Following are definitions of key scientific terms, as derived primarily from Borror (1960), Borror et al. (current running dates), Brown (1954), Carpenter (1938), Dorland (1932), Hanson (1959), Henderson & Henderson (1939), and Huber & Sharkey (1993) [see latter for illustrations], Jaeger (155), Jardine (1913), Pennak (1964), Service (2008), Smith (1906), Snodgrass (1935) Torre-Bueno (1937), Tuxen (1970) and Tweney & Hughes (1940).
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abdomen (adj., abdominal) = (Hymenoptera) The principal posterior division of the body, posterior to the leg-bearing
segments and composed of 10 or fewer apparent segments; in most Symphyta abdominal segment-1 is easily
recognized by its median split (cf. metasoma, propodeum). The posterior of three body regions.
abscissa (pl. abscissae) = A segment of a wing vein that is delimited by the intersection of other veins.
acaricide = Chemical that kills mites and ticks. Most acaricides are also insecticides.
accessory vein = An extra branch of a longitudinal vein (indicated by a subscript a; for example, an accessory of M, is designated Ml.
accessory pulsatile organ = Contractile organs that function to move hemolymph into and out of appendages.
accessory cell = A closed cell in the front wing of Lepidoptera formed by the fusion of 2 branches of the radius, usually
the R-2 cell
accessory gland = A secretory organ associated with the reproductive system; a gland associated with reproductive
organs or either males of females and producing substances accompanying the sperm or eggs.
accessory pulsatile organ = Contractile organs that function to move hemolymph into and out of appendages.
accessory vein = An extra branch of a longitudinal vein (indicated by a subscript "a").
acrosternite = The portion of a sternum anterior to the antecostal suture.
acrostichal bristles = One or more longitudinal rows of small bristles along the center of the mesonotum in Diptera.
acrotergite = The portion of a tergum anterior to the antecostal suture.
aculea (pl., aculeae) = Minute spines on the wing membrane in Lepidoptera.
aculeate = With aculea in Lepidoptera or a sting in Hymenoptera.
acuminate = Tapering to a long point.
acute = Pointed; forming an angle of less than 90°. Sharply angled, less than 90°
adecticous = A type of pupa in which the mandibles are immovable and nonfunctional.
adfrontal areas = A pair of narrow oblique sclerites on the head of a lepidopterous larva.
adventitious vein = A secondary vein, neither accessory nor intercalary, usually the result of cross veins lined up to form
a continuous vein = A wing vein that is not homologized with a standard wing vein =
aedeagus = The sclerotized median intromittent organ of a male insect = The male intromittent organ; the distal part of
the phallus; penis plus parameres.
aeropile = the opening in the chorion (egg shell) through which air enters, often covered by a plastron.
aestivation = Dormancy during a warm or dry season.
agamic = Reproducing parthenogenetically (without mating).
alinotum = The notal plate of the mesothorax or metathorax of a pterygote insect.
allometric growth = A genetically determined tendency for a certain body part to grow at a more rapid rate than other parts.
allomone = An external chemical signal that acts between different species to benefit the producer; e.g., to repel a
predator or parasitoid.
alula (pl., alulae) = A lobe at the base of the wing in Diptera; see calypter.
amastigote = Morphological form of species of Leishmania and Trypanosoma with a rounded body and without a flagellum
that occurs mainly in macrophages or muscle cells of vertebrate hosts.
ametabolous = Without metamorphosis (= changing little in form during the course of growth and molting).
amphipneustic = Only prothoracic and posterior abdominal spiracles present.
anal = Pertaining to the last abdominal segment (which bears the anus!; the posterior basal part Ifor example, of the wing.
anal crossing = Where A branches posteriorly from Cu+A in Odonata.
anal cell = A cell in the anal area of the wing; cell 1A of Diptera.
anal area of the wing = The posterior portion of the wing, usually including the anal veins.
anal lobe = A lobe in the posterior basal part of the wing.
anal loop = A group of cells in the hind wing of dragonflies between Cu-2, 1A, and 2A which may be rounded,
elongated or foot-shaped.
analogy = Similarity in function filling a common need but having a different evolutionary origin.
anamorphosis = Development of an organism in which one or more body segments are added posteriorly at each molt.
anapleurite = The upper and outer of the two incomplete subcoxal rings that form the thoracic pleurites.
anelli = ring-like segments
anelliform = ring-like
anellus = ring-like sgement
anemotaxis = Orientation with respect to currents in the air.
anepimeron = The portion of the anapleurite posterior to the pleural suture.
anepisternum = The portion of the anapleurite anterior to the pleural suture.
anisomorphal = A defensive allomone of the walkingstick Anisomorpha.
annulate = Ringed; formed in ring-like segments or color patterns.
annulated = With ringlike segments or divisions.
anteapical = Just proximad of the apex.
anteapical cell = A cell in the distal part of the wing of leafhoppers.
anteapical = Just proximal of the apex.
anteclypeus = An anterior division of the clypeus.
antecosta (pl., antecostae) = An internal ridge on the anterior portion of a tergum or sternum that serves as the site of
attachment of the longitudinal muscles.
antecostal sclerite = A sclerite of the metasternum, just anterior to the hind coxae.
antecostal suture = An external groove that marks the position of the internal antecosta.
antenna (pl., antennae; adj., antennal) = A paired, segmented sensory appendage of the head between the compound
eyes, which consists of 3 segments having intrinsic muscles and usually sensory in function.
antennal club = The enlarged distal segments of a clubbed antenna.
antennal fossa = A cavity or depression in which the antennae are located.
antennal groove = A groove in the head capsule into which the basal segment of the antenna fits.
antennule = The first antennae of Crustacea.
antenodal cross veins = Cross veins along the costal border of the wing, between the base of the wing and the nodus,
extending from the costa to the radius (Odonata).
antepenultimate = The 3rd from the last.
antepygidial bristle = One or more large bristles on the apical margin of the 7th (next to last) tergum in Siphonaptera.
anterior = Front; in front of.
antepygidial bristle = One or more large bristles on the apical margin of the seventh (next to the last) tergum
anterior = Front; in front of.
anterior cross vein = The r-m cross vein in Diptera.
anterodorsal = In the front and at the top or upper side.
anteromesal = In the front and along the midline of the body.
anteroventral = In the front and underneath or on the lower side.
antibiosis = Any deleterious effect on insect survival resulting from feeding on a resistant host.
anus = The posterior opening of the alimentary tract.
aorta = A blood-containing tube in insects that extends forward from the heart and is open anteriorly (nonpulsatile
portion of the dorsal blood vessel) = The anterior nonpulsatile portion of the dorsal blood vessel.
apex (pl., apices; adj., apical, apico-) = Part of a structure most remote from its point of attachment to the body.
apical = At the end, tip, or outermost part.
apical cell = A cell near the wing tip
apical cross vein = A cross vein enar the apex of the wing (Plecoptera, Homoptera).
apodeme = An invagination of the body wall forming a rigid process that serves for muscle attachment and for the
strengthening of the body wall. apolysis The separation of the epidermis from the cuticle (part of the process
of moltingl = An invagination of the exoskeleton that serves as a point of muscle attachment.
apolysis = Retraction of the epidermal cells from the inner surface of the endocuticle, the first step in molting.
apophysis (pl., apophyses) = A tubercular or elongated process of the body wall, either external or internal.
aposematism = Possession of vivid coloration that identifies an insect as having distasteful or unpleasant properties.
appendix = A supplementary or additional piece or part (eg., homopteran wing).
appetitive behavior = Searching behavior of variable pattern, seeking an appropriate stimulus.
apposition eye = A type of compound eye occuring in diurnal insects, in which each ommatidium is surrounded by a
shield of pigment.
apterous = Wingless
apterygote = A wingless insect of a group believed never to have had wings in its history (primitively wingless hexapod).
aquatic = Living in water.
arbovirus = A virus that multiples in a blood-sucking arthropod and is principally transmitted by the bite of arthropods to
vertebrate hosts. (e.g., Yellow Fever virus).
arcuate = Bent like a bow, or arched.
arculus = A basal cross vein between the radius and the cubitus in Odonata.
areola (pl., areolae; adj., areolate) = In Ichneumonidae, the median area of the propodeum that is enclosed by ridges.
areole An accessory cell Isee also basal areolel.
areolet = In Ichneumonidae, the small cell in the center of the forewing (submarginal cell opposite the 2nd m-cu cross vein);
the 1st radial sector cell.
arista = A large bristle, usually dorsally located, on the apical antennal segment in Diptera.
aristate = Bristlelike, with an arista; aristate antenna.
arolium (pl., arolia) = A pad-like median lobe between the tarsal claws (also see pretarsus) = A padlike structure at the
apex of the last tarsal segment, between the claws (Orthoptera); a padlike structure at the base of each tarsal
arrhenotoky = A form of parthenogenesis in which females are produced from fertilized eggs, males from unfertilized eggs.
articulation = A joint as between 2 segments or structures.
aspirator = A device with which insects may be picked up by suction.
associative learning = Acquisition of the capacity to associate a stimulus with a reward (or punishment).
asymmetrical = Not alike on the two sides.
asynchronous muscle = A rapidly contracting muscle in which the individual contractions are not initiated by a neuronal
impulse (compare synch‑onous orneurogenic musclel .
atrium (pl., atnal) = A chamber; a chamber just inside a body opening.
atrophied = Reduced in size, rudimentary.
attenuated = Very slender and gradually tapering distally.
auricle = A small lobe or earlike structure (Hymenoptera).
autocidal control = The use of insects for self destruction, mostly by release of sterile individuals.
autogenous = In blood-feeding insects, the ability to produce eggs without taking blood (as some mosquitoes).
auxiliary vein = The subcosta (Diptera)
axilla (pl., axillae; adj., axillar) = In groups with a transscutal articulation, posterolateral portion of the mesoscutum
separated from the mesoscutum lateral to the scutellum; usually triangular (also see scutum) = A triangular or
rounded sclerite laterad of the scutellum and usually just caudad of the base of the front wing (Hymenoptera).
axillary cell = A cell in the anal area of the wing (Diptera & Hymenoptera)
axillary sclerite = A small sclerite at the wing base that articulates with the thorax.
axillary sclerites = The small sclerites at the base of the wing that translate deformations of the thorax into movements.
axillula (pl., axillulae; adj., axillular) = In Chalcidoidea, the lateral subdivision of the scutellum delimited by a
axon = A fiber of a nerve cell that carries nerve impulses away from the cell body.
binominal nomenclature = The system of naming organisms with two names, generic and specific.
biological control = The employment of biotic agents, such as predators, parasitoids, and disease organisms, to control
populations of plants and animals. Particularly effective for organisms invading across geographic areas.
band = A transverse marking broader than a line.
basal areole = A small cell at the base of the wing; the cell at the base of the wing between Sc and R (Lepidoptera)
basal anal cell = An anal cell near the wing base; a cell at the base of the wing between IA and 2A (Plecoptera)
basal cell = A cell near the base of the wing, bordered at least in part by the unbranched portions of the longitudinal
veins; in the Diptera, one of the two cells proximad of the anterior cross vein and the discal cell (Diptera).
basal vein = A vein in about the middle of the front wing, extending from the median vein to the subcostal or cubital
vein; the first free segment of M (Hymenoptera).
basalare or basalar sclerite = An epipleurite located anterior to the pleural wing process.
base (pl., basal, basi-) = Part of a structure closest to its point of attachment to the body.
basement membrane = A noncellular membrane underlying the epidermal cells of the body wall.
basisternum That part of a thoracic sternum anterior to the sternacostal suture.
basitibial plate = In Apoidea, a small flat, hairless, raised region of the dorsal surface of the metatibia at its base.
beak = The protruding mouthpart structures of a sucking insect; proboscis.
bifid = Forked, or divided into two parts.
bilateral symmetry = See symmetry
bilobed = Divided into two lobes
biotic release = The sudden release of a population from its natural enemies, often resulting in a population explosion.
biotype = A population of a species that differs genetically from another population with respect to host affiliation (also
called "host race").
bipectinate = Having branches on two sides like teeth of a comb.
biramous = With two branches; consisting of an endopodite and an exopodite ICrustaceal.
bisexual = With males and females.
bituberculate = With two tubercles or swellings.
bivalved = With two valves or parts, clamlike.
bivoltine = Having two generations per year.
blastoderm = The thin cellular layer that surrounds the yolk of an egg.
bombyko = The sex attractant pheromone of the female silkworm moth.
blastoderm = The peripheral cell layer in the insect egg following cleavage.
book gills = The leaflike gills of a horseshoe crab.
book lung = A respiratory cavity containing a series of leaflike folds Ispiders).
borrow pit = A pit formed by an excavation, where earth has been "borrowed" for use elsewhere. boss A smooth lateral
prominence at the base of a chelicera Ispiders).
brace vein = A slanting cross vein; in Odonata, a slanting cross vein just behind the proximal end of the stigma.
brachypterous = With short wings that do not cover the abdomen.
brain = anterior ganglion of the nervous system, located above the esophagus; in insects composed of the protocerebrum,
deutocerebrum, and tritocerebrum.
brain hormone = A chemical messenger produced by neurosecretory cells in the brain that activates the prothoracic glands
to produce ecdysone jalso known as PTTH or prothoracicotropic hormone).
brevicomin = An aggregation pheromone of the bark beetle dendroctonus ore~icomis.
bridge cross vein = A cross vein anterior to the bridge vein (Odonata).
bridge vein = The vein that appears as the basal part of the radial sector, by M, and the oblique vein (Odonata).
brood = The individuals that hatch from the eggs laid by one mother; individuals that hatch at about the same time and
normally mature at about the same time.
bucca (pl., buccael) = A sclerite on the head below the compound eye and iust above the mouth opening (Diptera)
buccal cavity = The opening enclosed by the mouthparts, leading to the true mouth and the pharynx.
buccula (pl, bucculae) = One of two ridges on the underside of the head, on each side of the beak (Hemiptera).
bulla (pl., bullae) = In Ichneumonidae, unpigmented area of a vein where it is crossed by a wing fold or line of flexion.
bursa copulatrix = A pouch of the female reproductive system that receives the male genitalia during copulation. A pouch
on the median oviduct of the female that receives the aedeagus of the male.
bursicon = The hormone controlling tanning and expansion, produced by neurosecretory cells of the brain. A hormone involved
in the process of sclerotization.
caecum = (pl., caecae) A saclike or tubelike structure, open at only one end.
calamistrum = One or two rows of curved spines on the metatarsus of the hind legs of spiders.
calcaria = Movable spurs at the apex of the tibia.
callus (pl., callil) = A rounded swelling.
calypter (pl., calypteres) = One or two small lobes at the base of the wing, located just above the haltere (Diptera) (also
camera lucida = A device enabling one to make accurate drawings of objects seen through a microscope; when it is
attached to the eyepiece of a microscope; the observer can see the object under the microscope and his or her
drawing paper at the same time.
campaniform sensillum = A sense organ consisting of a dome‑shaped portion of the cuticle with associated sensory neuron;
perceives stresses in the cuticle = A sense organ consisting of a dome‑shaped cuticular area into which
the sensory cell process is insertcd like the clapper of a bell.
campestral = In epidemiology used to describe transmission occurring in fields and open spaces, such as plague transmission
among wild rodents or in woods & forests.
campodeiform larva = A larva shaped like the dipluran Campodea (that is, elongate and flattened), with well‑developed
legs and antennae, and usually active.
cantharidin = A defense allomotle of blister beetles (also known as "Spanish fly").
capitate = With an apical knoblike enlargement; capitate antenna.
carapace = A hard dorsal covering consisting of fused dorsal sclerites (Crustacea)
cardo (pl., cardines) = The basal segment or division of a maxilla; one of two small laterobasal sclerites in the millipede
gnathochilarium. The basal part of the maxilla.
carina (pl., carinae; adj. , carinate) = A ridge or raised line.
carinate = Ridged or keeled.
carnivorous = Feeding on the flesh of other animals.
caste = A form or type of adult in a social insect (termites &ants).
catapleurite = The lower and inner of the two incomplete subcoxal rings that form the thoracic pleurites lalso called the
catepleurite, katepleurite, and coxopleurite.
catepimeron = The portion of the catapleurite posterior to the pleural suture.
catepistetnum = The portion of the catapleurite anterior to the pleural sulcus.
caterpillar = An eruciform larva; the larva of a butterfly, moth, sawfly, or scorpionfly.
caudad = Toward the tail, or toward the posterior end of the body.
caudal = Pertaining to the tail or posterior end of the body.
caudal filament = A threadlike process at the posterior end of the abdomen.
cell = The area between the veins of a wing; it is closed when completely surrounded by veins, otherwise it is open. Cell (of the wing)
A thin, membranous area surrounded by veins
Cephalothorax = head + thorax
cercus (pl., cerci), An antennalike sensory appendage arising from the posterior end of the abdomen.
cenchrus (pl., cenchri) = In Symphyta, a paired circular, or oval structure on the sublateral portion of the metascutum.
Roughened pad on the metanotum of sawflies (Symphyta) serving to hold the wings in place when folded over
cephalad = Toward the head or anterior end.
cephalic = On or attached to the head; anterior.
cephalothorax = A body region consisting of head and thoracic segments (Crustacea and Arachnida).
cercus (pl., cerci; adj., cercal) = A paired, posterior, sensory appendage of the last (morphological 1/10th) abdominal
tergum, which usually bears sevgeral setae = With a reduction of the apical segments of the metasoma, the cerci
often seem to be on a more anterior segment. One of a pair of appendages at the posterior end of the abdomen.
cervical = Pertaining to the neck or cervix.
cervical sclerite = A sclerite located in the lateral part of the cervix, between the head and the prothorax.
cervix = The largely membranous neck region of an insect, between head and thorax.
chaetotaxy = The arrangement and nomenclature of the bristles on the exoskeleton (Diptera).
cheek = The lateral part of the head between the compound eye and the mouth (see genai
chela (pl., chelae; adj., chelate) = In Dryinidae, the modified tarsus in which the apical tarsomere forms a clasping
structure with its opposable tarsal claw; a pincer.
chelate = Pincerlike, having two opposable claws.
chelicera (pl., chelicerae) = One of the major elements in the mouthparts of spiders and related arthropods; not jawlike,
but in the form of fangs, pincers, or piercing organs. One of the anterior pair of appendages in arachnids.
cheliped = A leg terminating in an enlarged pincerlike structure (Crustacea).
chemoreceptor = A sensillum capable of detecting chemicals (by olfaction and/or gustationi. A sense organ modified for the r
eception of chemical stimuli.
chemotaxis = Orientarion with respect to a chemical gradient.
chitin = A nitrogenous polysaccharide formed primarily of units of N‑acetyl glucosamine, occurring in the cuticle of arthropods.
The tough, insoluble polysaccharide making up a major part of the insect procuticle
chordotonal organ = A sense organ, the cellular elements of which form an elongate structure attached at both ends to
the body wall. An elongate sense organ attached to the inner surface of the body wall and sensitive to stretching and to
choriogenesis = Formation of the shell (chorion) of the egg.
chorion = The outer shell of an arthropod egg.
chrysalis (pl., chrysalids or chrysalides) = The pupa of a butterfly.
cibarium = A preoral cavity enclosed by the labrum anterior, the hypopharynx or labium posteriorly, and the mandibles
and maxillae laterally.
circadian rhythm = An endogenous rhythm involving a response at about 24‑hour intervals .
circulatory virus = A virus that circulates within the body of an insect before being introduced into a new host.
cleptoparasite = A "thief parasite," one that consumes the food stored by another insect in a nest.
climatic release = Release of climatic restraints, such as a period of favorable weather or entry into a favorable region,
resulting in population increase.
clypeus = A sclerite on the front of the head, above the labrum.
coevolution = An evolutionary change in a trait of individuals of one population in response to a trait of individuals of
a second population, followed by an evolutionary response of the second population to a change in the first.
colleterial gland = An accessory gland of the female that produces the ootheca.
commensal = Animals living together or in closs association.
communication = The production of a signal by an individual that influences the behavior of another individual and that
is mutually beneficial.
companionate planting = The intercropping of certain repellent plants with crop plants.
circumesophageal connective = A nerve connecting the tritocerebral lobes of the brain with the subesophageal ganglion.
class = A subdivision of a phylum or subphylum, containing a group of related orders.
claval lobe = The posterior portion of a wing behind the claval fold and in front of the jugal fold, when present (also see
claval fold = The furrow on the forewing jsut anterior to, and aprallel with, vein 1A, and extending to the claval notch
on the wing margin.
claval suture = The suture of the front wing separating the clavus from the corium (Hemiptera).
claval vein = A vein in the clavus (Hemiptera, Homoptera).
clavate = Clublike, or enlarged at the tip; clavate antennae.
clavus = The oblong or triangular anal portion of the front wing (Hemiptera and Homoptera)
claw tuft = A dense tuft of hairs below the claws (spiders)
cleft = Split or forked.
cleptoparasite = A parasite that feeds on food stored for the host larvae.
closed cell = A wing cell bounded on all sides by veins.
closed coxal cavity = One bounded posteriorly by a sclerite of the same thoracic segment of front coxal cavities, (Co
leoptera) or one completely surrounded by sternal sclerites and not touched by any pleural sclerites of middle
coxal cavities (Coleoptera).
club = The enlarged apical flagellar segment or segments of an antenna (also see funicle).
clubbed = With the distal part ior segmentsl enlarged; clubbed antennae.
clypeus (adj. clypeal) = The medial sclerite of the head immediately above the labrum; often defined dorsally and
laterally by the epistomal groove = A sclerite on the lower part of the face, between the frons and the labium.
coarctate larva = A larva somewhat similar to a dipterous puparium, in which the skin of the preceding instar is not
completely shed but remains attached to the caudal end of the body; the sixth instar of a blister beetle, also
called a pseudopupa.
coarctate pupa = A pupa enclosed in a hardened shell formed by the last larval skin (Diptera).
cocoon = A silken case inside which the pupa is formed.
collophore = A tubelike structure located on the ventral side of the first abdominal segment of Collembola.
collum = The tergite of the first segment (Diplopoda).
colon = The large intestine; that part of the hindgut between the ileum and the rectum.
colulus = A slender pointed structure Iying just anterior to the spinnerets (spiders1
commensalism = A living together of two or more species, none of which is injured thereby and at least one of which
commissure = A structure (trachea or nervel that connects the left and right sides of a segment.
common oviduct = The median tube of the female internal genitalia leading from the lateral oviducts to the gonopore.
competitive exclusion principle = The concept that two species cannot long coexist if they have identical niches.
complete metamorphosis = Striking changes between larva and adult, with an intervening pupal stage.
conditioning = See Associative learning.
contest competition = Competition involving aggressive interactions between individuals.
coprophagous = Feeding on fecal material.
cornicle = One of a pair of tubelike processes on the abdomen of aphids, secretes an allomone and an alarm pheromone.
cornicles = dorsal tubular structures on posterior abdomen
corpus allatum (pl., corpora allata) = A small endocrine gland situated behind the brain, the source of juvenile hormone.
corpus cardiacum (pl., corpora cardiaca) = A small organ of nervous origin just behind the brain, associated with
storage and release of PTTH and other hormones.
corpus pedunculatum (pl., corpora pedunculata) See Mushroom body.
compound eye = An eye composed of many individual elements or ommatidia, each of which is represented externally
by a facet; the external surface of such an eye consists of circular facets that are very close together or of facets
that are in contact and more or less hexagonal in shape.
compressed = Flattened from side to side (higher than wide).
concave = Pertaining to a linear structure, margin, or surface that is curved inward (cf. convex).
concave vein = A vein protruding from the lower surface of the wing.
condyle = A knoblike process forming an articulation.
connate = Fused together or immovably united.
connective = A structure (such as a trachea or nervel that runs from one segment to another.
constricted = Narrowed.
contaminative = Infection or transmission is contaminative when the pathogenic organism gains entrance by way of abrasions,
by fecal wastes deposited on the skin, etc.
contiguous = Touching each other.
convergent = Becoming closer distally.
convex vein = A vein protruding from the upper surface of the wing.
convex = Pertaining to a linear structure, margin, or surface that is curved outward (cf. concave).
corbicula (pl., corbiculae) = In Apiformes, the concave, smooth region of the metatibia that is margined by a fringe of setae
arising from the margins; it forms a pollen basket = A smooth area on the outer surface of the hind tibia,
bordered on each side by a fringe of long curved hairs, which serves as a pollen basket (beesl)
corium = The elongate, usually thickened, basal portion of the front wing (Hemiptera).
cornea = The cuticular part of an eye.
cornicle = One of a pair of dorsal tubular structures on the posterior part of the abdomen (aphids).
corniculi (sing., corniculus) = See urogomphi.
coronal suture = A longitudinal suture along the midline of the vertex, between the compound eyes.
corpus allatum (pl., corpora allata) = One of a pair of small structures immediately behind the brain, involved in
secretion of juvenile hormone.
costa = A longitudinal wing vein usually forming the anterior margin of the wing; a sclerotized ridge in the cuticle.
costal area = The portion of the wing immediately behind the anterior margin.
costal cell = The wing space between the costa and the subcosta.
costal break = A point on the costa where the sclerotization is weak or lacking or the vein appears to be broken (Diptera)
costal notch = The excision of the wing margin between the apex of the costal vein and the base of the stigma.
coxa (pl., coxae; adj., coxal) = The first segment of a leg, between the body and the trochanter = The basal segment of
the leg = The most basal segment of the insect leg, articulating with the thorax.
coxopleurite = See catapleurite.
coxopodite = The basal segment of an arthropod appendage.
coxosternum = A sclerite representing the fusion of the sternum and the coxopodites of a segment.
crawler = The active first instar of a scale insect.
cremaster = A spinelike or hooked process at the posterior end of the pupa, often used for attachment (Lepidoptera).
crenulate = Wavy, or with small scallops.
cribellum = A sievelike structure Iying just anterior to the spinnerets (spiders).
crochets (pronounced croshays) = Hooked spines at the tip of the prolegs of lepidopterous larvae.
crop = An expansible part of the foregut that holds food until it can be passed into the midgut = The dilated posterior
portion of the foregut, just behind the esophagus.
crypsis = Close resemblance of an animal to its physical or biotic background (also called protective coloration).
cross vein = A vein connecting adjacent longitudinal veins.
cruciate = Crossing; shaped
cryptonephridia = Malpighian tubules that are closely associated with the hind gut and surrounded by a membrane, thus
separating this complex from the rest of the hemocoel.
ctenidium (pl., ctenidia) = A row of stout bristles like the teeth of a comb.
cubito‑anal cross vein = A cross vein between the cubitus and an anal vein.
cubitus = The longitudinal vein immediately posterior to the media.
cultural control = Modification of the environment‑‑for example, by tillage‑‑to make it less attractive to pests.
cuneus = Trriangular apical part of thickened portion of wing
cuticle = The noncellular outer portion of the integument.
cuticulin = The tough, insoluble substance making up the outer surface of the epicuticle, containing cross‑linked lipid
and protein molecules.
cytoform (or -type) = A cytologically defined population with a distinctive chromosomal complement.
cytoplasmic polyhedrosis virus (CPV) = A virus that develops in the cytoplasm of host cells, chiefly in the midgut.
Darwinian fitness = differential reproduction, in terms of the number of genes an individual passes to the next generation.
definitive host = Host in which parasites reach maturity. it occurs in arthropod vectors but also in malaria parasites.
depressed = Flattened from top to bottom (wider than high).
density‑dependent factor = A factor that causes a level of mortality that varies with the number of individuals in the population.
deutocerebrum = The middle section of the brain, which innervates the antennae.
diapause = A state of arrested behavior, growth, and development that occurs at one stage in the life cycle.
dichoptic = A condition of the head in adult Diptera in which the eyes are widely separated from each other.
diel periodicity = Periodicity that occurs about every 24-hours.
digitus = Pad-like lobe of male genitalia
direct pest = A pest insect that attacks a part of a plant that is harvested, as contrasted to an indirect pest.
diurnal = Refers to activity during the daylight hours, such as blood-feeding simulids.
dorsal = Referring to the upper surface (back) of an animal.
dorsal diaphragm = A muscular shcet underlying the heart which assists in the flow of blood.
dorsal longitudinal muscles = Muscles running longitudinally, dorsally in insect segments, in the thorax powering the
downstroke of the wings of most insects.
dorsoventral muscles = Muscles inserting on the dorsum of the thorax and originating ventrally, powering the upstroke
of the wings of most insects.
dorsum = The upper surface (back) of an animal .
Dufour's gland = An exocrine gland on the ventral, posterior part of the abdomen of female Hymenoptera, the source
of pheromones serving diverse functions.
disc (adj., discal) = The central surface of any structure.
dorsal diaphragm = An incomplete wall of muscle separating the area around the dorsal blood vessel (the pericardial
sinus) from the rest of the hemocoel.
dorsocentral bristles = A longitudinal row of bristles on the mesonotum, just laterad of the acrostichal bristles (Diptera).
dorsolateral = At the top and to the side.
dorsomesal = At the top and along the midline.
dorsoscutellar bristles = A pair of bristles on the dorsal portion of the scutellum, one on each side of the midline (Diptera).
dorsoventral = From top to bottom, or from the upper to the lower side.
dorsum = The back or top (dorsal) side.
Dyar's rule = The increase in width of the larval head capsule by a factor of 1.2‑1.4 from one molt to the next.
ecdysis = Splitting and casting off of the old cuticle, the major event in molting.
ecdysone = A molting hormone, secreted by the prothoracic glands.
eclosion = Hatching of the egg, or emergence of the adult insect at the terminal molt.
ecological homolog = One of two or more species having most niche parameters in common .
economic injury level (EIL) = The level of damage to a crop that is equal in value to the cost of suppressive measures.
economic threshold (ET) = The level of damage by a pest that serves to wam the agriculturalist of impending problems.
ecosystem = A biological community considered in relation to its physical environment.
egg‑development neurosecretory hormone (EdNH) = A product of the brain neurosecretory cells that stimulates vitellogenesis
in the female mosquito.
ejaculatory duct = A median duct that carries the sperm from the intemal reproductive system to the exterior.
elytra = Thickened front wings (eg = , Coleoptera)
elytron (pl., elytra) = The hardened front wing of a beetle.
emarginate = Notched; with an obtuse, rounded, or quadrate section cut out of a margin.
encapsulation = The enclosure of a parasitoid larva within the blood of the host by a layer of hemocytes.
endemic = Describes a disease in a human population that is constantly present and quite stable. Also the evolutionary
origin of an organism.
endocrine gland = A gland that discharges its products (hormones) to the inside (as contrasted to an exocrine gland).
endocuticle = The inner zone of the procuticle, softer and lighter in color than the exocuticle.
endogenous activity = Nervous discharges that arise spontaneously, in the absence of stimulation.
endodterygote = An insect that develops through the immature stages as a larva with wings retained internally as imaginal.
endodont mandible = A mandible with the teeth facing inward so that when the mandibles are closed their tips point
toward each other's base (cf., exodont).
endophagic = Describes insects, such as mosquitoes, that enter houses to feed on blood.
endophilic = Describes insects, such as some mosquitoes, that rest in houses before or aftr feeding on blood in houses or
entomophagous = Feeding on insects.
entomopox virus = A virus that multiplies in the cell cytoplasm of fat body and blood cells in a variety of insects.
epicuticle = The outer zone of the insect cuticle, rich in lipid and protein and lacking chitin.
epidemic = Occurrence of a disease in the human population where the number of cases exceeds the normal expected number.
epidermis = The single outer cell layer of the body, which secretes the cuticle.
epimorphosis = A type of development in which the insect emerges from the egg with its full complement of body segments
(opposite of anamorphosis).
epimastigote = Morphological form of a trypanosome with the flagellum emerging about halfway in the body but remaining
attached to the cell membrane.
equilibrium position (EP) = In insect bioeconomics, the average density of a potential pest on a specific crop.
esophagus = A tubular portion of the foregut, behind the pharynx.
epicnemial carina = The ridge on the mesopleuron that somewhat parallels the anterior margin of the mesepisternum and
that delineates the posterior margin of the epicnemium.
epicnemium (adj., epicnemial) = The anterior portion of the mesopleuron delimited posteriorly by the epicnemial carina
(also see prepectus).
epimeron (pl., epimera; adj., epimeral) = The portion of a pleuron posterior to the pleural groove (cf. episternum).
epipygium = In Chalcidoidea, a small, somewhat sclerotized, fingernail-like flap attached to the last metasomal tergum
between the cerci.
episternal groove = A groove on the mesopleuron, extending ventrally from a pit under the base of the forewing and,
when complete, reaching the anteroventral margin of the mesothorax.
episternum (pl., episterna; adj., episternal) = The portion of a pleuron anterior to the pleural groove (cf. epimeron).
epistomal groove = A groove defining the lateral and dorsal margin of the clypeus.
epomia (pl., epomiae) = In Ichneumonoidea, an oblique ridge crossing the transverse furrow on the side of the pronotum.
eusociality = A type of social behavior involving overlap of generations, cooperative brood care, and a caste system in
which many colony members are sterile.
exocrine gland = A gland that discharges its products to the outside (as contrasted to an endocrine gland).
exocuticle = The outer portion of the procuticle, generally harder and darker than the inner portion (endocuticle).
exodont = Extended outwards
exodont mandible = A mandible with the teeth facing outward so that when the mandibles are closed their tips point
anteriorly or away from each other (cf. endodont).
exophagic = Term applied to insects that feed on blood outdoors (e.g., Aedes aegypti & Simuliidae).
exopterygote = An insect that retains its wing pads externally through its immature stages.
exoskeleton = A skeleton extemal to the remainder of the body, the muscles attaching to its inner surface.
extrinsic = Having its origin outside the limits of an organ with which it is associated.
face (adj., facial) = In Parasitica, the anterior surface of the head between the eyes from the ventral margin of the toruli
to the oral cavity, excluding the clypeus; in Symphyta and Aculeata, anterior surface of the head between the
eyes from the ocelli to the oral cavity, including the clypeus.
face = The front of the head, below the frontal suture (Diptera).
facet = The external surface of an individual compound‑eye unit or ommatidium. falx An interantennal suture with internal
sclerotized margins connecting the upper ends of the antennal fossae ISiphonaptera).
facial fovea = In Apoidea, a depressed, often finely densely pubescent area along the inner orbit of a compound eye.
family = A subdivision of an order, suborder, or superfamily, containing a group of related genera, tribes, or subfamilies.
Family names of animals end in "idae".
farnesene = An alarm pheromone of aphids, secreted from the cornicles.
fat body = Accumulation of large cells in the hemocoel that store metabolites and are centers of intermediary metabolism.
femur (pl., femora) = The third segment of the insect leg, beyond the trochanter and before the tibia.
fibril = The contractile unit of a muscle cell (fiber).
filter chamber = A modification of the gut of many Homoptera (such as aphids), permitting much water and some
carbohydrates to bypass the midgut.
filter feeder = An insect that seines particles from water by means of brushes or webs.
fixed action pattern = A segment of behavior performed in a stereotyped, species‑specific manner.
flagellum = The outermost part of the antenna, beyond the scape and pedicel, usually divided into many subsegments
follicle = A tubule of the testis in which sperm are produced.
foulbrood = A bacterial disease of honey bee larvae and pupae.
founder effect = Speciation resulting from the establishment of a small population in an entirely new area and the
subsequent divergence of the resulting population from the parent stock.
frontalin = A sex attractant pheromone of male bark beetles.
fastigium = The anterior dorsal surface of the vertex (grasshoppers). fat body An amorphous organ involved in intermediate
metabolism, storage, and storage excretion.
feces (or faeces) = Excrement, the material passed from the alimentary tract through the anus.
felt line = In Mutillidae adn Bradynobaenidae, a longitudinal line of flattened setae and secretory pores laterally on
metasomal tergum 2.; narrow longitudinal band of relatively dense, closely appressed hairs of Mutillidae).
femur (pl., femora; adj., femoral) = The 3rd segment of a leg, between the trochanter and tibia.
fibula = A more or less triangular jugal lobe in the front wing that serves as a means of uniting the front and hind wings
filament = A slender threadlike structure. file A filelike ridge on the ventral side of the tegmen, near the base; a part of the stridulating
mechanism in crickets and long‑horned grasshoppers.
filiform = Hairlike or threadlike, filiform antenna.
filter chamber = A modification of the alimentary canal in Homoptera in which the anterior portion of the midgut is
closely associated with the hindgut.
flabellate = With fanlike processes or projections; flabellate antenna.
flabellum (pl., flabella) = A fanlike or leaflike process (Hymenoptera. In Apiformes, a small thin plate of the apex of the glossa.
flagellomere = A segment-like subdivision of the flagellum; it is numbered consecutively from the base of the flagellum.
One of the subsegments of the flagellum.
flagellum (pl., flagella; adj., flagellar) = The 3rd primary division or segment of the antenna; it articulates with the pedicel
basally and almost always is subdivided into segments (= flagellomeres) = A whiplike structure that part
of the antenna beyond the second segment.
flexor muscle = A muscle that decreases the angle between two segments of an appendage.
foliaceous = Leaflike.
follicle = A minute cavity, sac, or tube.
follicular epithelium = Layer of epithelial cells surrounding the oocyte.
fontanelle = A small, depressed, pale spot on the front of the head between the eyes (lsoptera).
foramen (pl., foramina) = A hole in the body wall through which vessels or nerves pass = The foramen magnum is the
central hole in the back of the head; the propodeal foramen is the hole in the posterior area of the propodeum.
foramen magnum = The opening on the posterior side of the head, through which pass the internal structures that extend
from the head to the thorax; also occipital foramen.
foregut = The anterior portion of the alimentary tract, from the mouth to the midgut.
fossorial = Fitted for or with the habit of digging. frass Plant fragments made by a wood‑boring insect, usually mixed
frenulum = A bristle or group of bristles arising at the humeral angle of the hind wing Lepidoptera).
frenum (pl., frena; adj., frenal) = In Chalcidoidea, the transverse line on the scutellum that delineates a posterior portion
of the scutellum, the frenal area.
frons = The area of the head bvetween the ventral margin of the toruli and the anterior margin of the median ocellus (this
is not equivalent to the true frons of larvae). The head sclerite bounded by the frontal lor frontogenali and
epistomal sulci and including the median ocellus.
front = That portion of the head between the antennae, eyes, and ocelli; the frons.
frontal bristles = Bristles above the antennae, away from the edge of the compound eye (Diptera).
frontal carina = A longitudinal ridge or pair of ridges on the frons between (and sometimes partly covering) the toruli.
frontal lunule = A small crescent‑shaped sclerite located just above the base of the antennae and below the frontal suture
frontal suture = One of two sutures arising at the anterior end of the coronal suture and extending ventrad toward the
epistomal sulcus; a suture shaped like an inverted U, with the base of the U crossing the face above the bases
of the antennae and the arms of the U extending downward on each side of the face (Diptera; actually a ptilinal
frontal vitta = An area on the head between the antennae and the ocelli (Diptera).
fronto‑orbital bristles = Bristles on the front next to the compound eyes (Diptera).
frontogenal suture = (or sulcusi) A more or less vertical suture on the front of the head, between the frons and the gena.
funicle (adj., funicular) = A group of flagellomeres between the pedicel and the club.
funiculus (or funicle) = The antennal segments between the scape and the club ICole6pteral, or between the pedicel and
club in Hymen6pteral.
furca = A fork or forked structure; a forked apodeme arising from a thoracic sternum.
furcula = The forked springing apparatus of the Collembola.
galea (pl., galeae) = The outer apical lobe of the maxilla that articulates basally with the stipes. An apical lobe of the maxilla
of an insect, borne by the stipes.
gall = An abnormal growth on a plant, produced by stimulation of an insect or other organism and housing that organism.
ganglion (pl., ganglia) = A mass of nervous tissue, the basic anatomical unit of the central nervous system.
gastric caecum (pl., caeca) = A fingerlike, anterior extension of the midgut that sen~es a function in food absorption.
genitalia = Structures associated w ith the release of sperm or eggs.
gall = An abnormal growth of plant tissues, caused by the stimulus of an animal or another plant.
ganglion (pl., ganglia) = A knotlike enlargement of a nerve, containing a coordinating mass of nerve cells.
gaster = The rounded part of the abdomen posterior to the nodelike segment or segments IHymen6ptera Ap6crital .
gastric caecum = Caecum located at the anterior portion of the midgut.
gastrocoelus-thyridium (pl. gastrocoeli) = In Ichneumonidae, the usually transverse impression anterolaterally on
metasomal tergum 2 = The gastrocoelus includes the thyridium, which is the surface area with specialized
sculpture, while the gastrocoelus is the impression iteself.galea (pl., galeae) = The outer apical lobe of the
maxilla, articulated basally with the stipes.
gena (pl., genae; adj., genal) = The cheek; the lateral part of the head between the compound eye and, when present,
the occipital carina; otherwise, the lower (in hypognathous head) or anterior (in prognathous head) part of the
back of the head between the compound eye and the occiput = The part of the head on each side below and
behind the compound eyes, between the frontal and occipital sulci.
genal comb = A row of strong spines borne on the anteroventral border of the head (Siphonaptera).
gneration = From any given stage in the life cycle to the same stage in the offspring.
geniculate = Elbowed, or abruptly bent; geniculate antenna.
genital chamber = See bursa copulatnx.
genitalia = The sexual organs and associated structures; the external sexual organs.
genovertical plate = An area on the head above the antenna and next to the compound eye (Diptera; also called orbital plate).
genus (pl., genera) = A group of closely related species; the first name in a binomial or trinomial scientific name. Names
of genera are latinized, capitalized, and when printed are italicized.
germ band = A thickening of the klastoderm that produces the embryo.
germarium = An area at the tip of the sperm follicles or ovarioles where sperm or egg formation is initiated = Apical portion
of the ovariole or sperm follicle.
giant axon = A large‑diameter axon of an interneuron that traverses several body segments and conducts messages quickly.
glial cell = A cell surrounding the axon of a neuron.
gill = Evagination of the body wall or hindgut, functioning in gaseous exchanges in an aquatic animal.
gonopore = The external opening of the reproductive tract.
granulosis virus (GV) = A virus that multi plies in both the nucleus and cytoplasm of host cells, usually in the fat body.
glabrous = Smooth, without hairs.
globose, globular = Spherical or nearly so.
glossa (pl., glossae) = The paired, fused, median lobe of the labium articulated basally with the prementum. One of a pair of
lobes at the apex of the labium between the paraglossae (in bees).
glymma (pl., glymmae) = In Ichneumonidae, the paired groove or pit on the side of metasomal segment 1 between its
base and the spiracle; it is nearly always present when sternum 1 is free from tergum 1 but absent when tergum
1 and sternum 1 are fused.
gnathochilarium = A platelike mouthpart structure in the Diplopoda, representing the fused maxillae and labium.
gonangulum = A sclerite of the female external genitalia derived from the second gonocoxa, connecting the second
gonocoxa, ninth tergum, and first gonapophysis.
gonapophysis (pl., gonapophyses) = A mesal posterior process of a gonopod, in the female forming the ovipositor; first
or second valvula.
gonocoxa = A modified coxa that forms a part of the external genitalia ( = valviferi).
gonoplacs = Lateral sheaths enveloping the ovipositor in pterygotes ( = third valvulael).
gonopod = A modified leg that forms a part of the external genitalia.
gonopore = The external opening of the reproductive organs.
gonostylus = Stylus of a genital segment labdominal segment 8 or 91.
gonotrophic cycle = Time from first blood-feeding to oviposition and subsequently between successive ovipositions.
Also referred to as "The Ovarian Cycle."
gregarious = Living in groups.
grub = A scarabaeiform larva; a thick‑bodied larva with a well‑developed head and thoracic legs, without abdominal
prolegs, and usually sluggish.
groove = A linear impression on a sclerite (also see suture).
gula = A sclerite on the ventral side of the head between the labium and the foramen magnum.
gular sutures = Longitudinal sutures, one on each side of the gula.
gustation = Taste detection of chemicals in liquid.
gynandromorph = An abnormal individual containing structure characteristics of both sexes (usually male on one side
and female on the other)
habitat = The physsical environment where an animal lives (e.g., for entomology it is the skin of scabies mites, streams for
simuliid larvae and animal nests for ixodid ticks and other animals.
habituation = Leatning not to respond to a stimulus that provides no reward or punishment .
haemocoel = The main body cavity of arthropods where insect blood (the haemolymph) circulates.
hair pencils = Tufts of fine setae serving to dust pheromone‑coated particles onto a memher of the opposite sex.
haltere (pl, halteres) = A small knobbed structure on each side of the metathorax, formed from a modified hind wing Diptera).
(A modified hind wing of a fly (Diptera), acting to maintain flight stability.
haplodiploidy = A type of parthenogenesis in which males are produced from unfertilized eggs and are therefore haploid,
while the females are diploid.
hamuli (Sing., hamulusl) = Minute hooks; a series of minute hooks on the anterior margin of the hind wing, with which
the front and hind wings are attached together lHymenopterai .
haustellate = Formed for sucking, the mandibles not fitted for chewing (or absent).
haustellum = A part of the beak (Diptera).
head = The anterior body region, which bears the eyes, antennae, and mouthparts. The principal anterior division of the body;
it bears the mouthparts and antennae.
heart = A muscular tube extending dorsally and longitudinally through the insect abdomen, continuous with the aorta,
serving in circulation of blood = The posterior pulsatile portion of the dorsal blood vessel
hematophagous = Feeding on blood.
hemelytron (pl., hemelytra) = The forewing of an insect that is sclerotized basally but membranous apically (literally,
half an elytron; applied chiefly to Hemiptera).
hemimetabolous = Having incomplete or simple metamorphosis, that is, showing gradual change from molt to molt, with
externally developing wing pads. (Odonata, Ephemeroptera, Plecoptera), with nymphs aquatic.
hemocoel = The blood‑filled body cavity or arthopods.
hemocyte = A blood cell =
hemocytes = Blood cells.
hemolymph = The "blood" of insects, combining functions of the lymph and blood of vertebrates (other than respiration).
The blood of arthropods.
herbivorous = Feeding on plants.
hermaphroditic = Possessing both male and female sex organs.
hereditary transmission = Involves a female vector passing disease organisms to her eggs and therefore to the next generation.
hertz = Cycles per second (Hz).
heterodynamic life cycle = A life cycle in which there is a period of dormancy.
heterogamy = Alternation of bisexual with parthenogenetic reproduction.
heteromerous = The three pairs of tarsi differing in the number of segments lColeoptera, for example, with a tarsal
formula of 5‑5‑41.
hibernation = Dormancy during the winter. Also, a period of inactivity and/or altered behavior caused by cold weather.
hindgut = The posterior portion of the alimentary tract, between the midgut and the anus.
holarctic = The two, Palaearctic and Nearctic regions combined.
holocrine secretion = Release of enzymes by disruption of the entire cell.
holometabolous = Having complete metamorphosis, passing through egg, larval, pupal, and adult stages.
homeostasis = Maintenance of a functionally steady state in the body, in the colony of social insects, or in an ecos~stem.
holoptic = The eyes contiguous above (Dipterai). Usually for adult Diptera wehree eyes meet or almost meet each other.
homodynamic lile cycle = A life cycle in which there is continuous development, without a period of dormancy.
homology = Similarity in structure resulting from having had a common evolutionary origin.
honeydew = The liquid excretions of sucking insects (Homoptera), consisting largely of water and sugars.
hormone = An intemal chemical signalproluced by an endocrine gland and carried to the tissues by the hemolymph.
horns = Found around antennae in Chalcididae
host preference = The preferred hosts (e.g., species, sex, age) of an arthropod in an area where a choice exists.
host race = A population of a species that shows a genetically determined preference for a particular host plant or animal
hydrostatic skeleton = Maintenance of body form by the pressure exerted by muscles on a fluid‑filled body cavity, most
important in soft‑bodied larvae.
hypermetamorphosis = A type of development in which there are two or more quite distinct larval forms sequentially.
hyperparasitoid = An insect that is a parasitoid of a parasitoid.
hypopharynx = A tonguelike structure in the buccal cavity, associated with the labium.
homonym = One and the same name for two or more different things (taxa)
honeydew = Liquid discharged from the anus of certain Homoptera.
hornworm = A caterpillar (larva of Sphingidae) with a dorsal spine or horn on the last abdominal segment.
horny = Thickened or hardened.
host = The organism in or on which a parasite lives; the plant on which an insect feeds.
humeral = Pertaining to the shoulder; located in the anterior basal portion of the wing.
humeral angle = The basal anterior angle or portion of the wing.
humeral bristles = The bristles on the humeral callus (Diptera).
humeral callus = One of the anterior lateral angles of the thoracic notum, usually more or less rounded (Diptera).
humeral cross vein = A cross vein in the humeral portion of the wing, between the costa and subcosta.
humeral plate = The anterior sclerite of the wing at the base of vein C.
humeral suture = The mesopleural suture (Odonata).
humeral vein = A branch of the subcosta that serves to strengthen the humeral angle of the wing (Neuroptera,
humerus (pl., humeri) = The shoulder; the posterolateral angles of the pronotum (Hemiptera1
humulus (pl., hamuli) = One of a series of small bristle-like hook on the anterior martin of the hind wing; in some groups
there may be a basal and an apical series of hamuli.
hyaline = Like glass, transparent, colorless.
hypermetamorphosis = A type of complete metamorphosis in which the different larval instars represent two or more
different types of larvae.
hyperparasite = A parasite whose host is another parasite.
hypodermis = See epidermis.
hypognathous = With the head somewhat at a right angle to the plane of the body (vertical), so the mouthparts are
directed ventrally (cf. prognathous).
hypopharynx = A median mouthpart structure anterior to the labium; the ducts from the salivary glands are usually
associated with the hypopharynx, and in some sucking insects the hypopharynx is the mouthpart structure
containing the salivary channel.
hypopleural bristles = A more or less vertical row of bristles on the hypopleuron, usually directly above the hind coxac
hypopleuron (pl, hypopleura) = The lower part of the mesepimeron; a sclerite on the thorax located just above the hind
hypopygium (adj., hypopygial) = The last visible sternum of the abdomen.
hypostigmatic cell = The cell immediately behind the point of fusion of Sc and R (Neuroptera, Myrmeleontoidea).
hypostomal bridge = The sclerotized posterior part of the head that sometimes separates the foramen magnum from the
oral cavity (the bridge may sometimes be formed by the median fusion of the postgena or gena and is then
called the postgenal or genal bridge) = Mesal extension of the hypostomae on each side to meet below the
hypostomal carina = The ridge on the back of the head along the oral cavity that normally delimits the hypostoma from
the postgena and occiput.
Hz Hertz = (cycles per second).
ileum = The anterior part of the hindgut, preceding the rectum.
imaginal disc = A group of cells set aside in the embryo and maintained through the larval stage as a center of
development of adult structures .
imago = The terminal instar, or adult.
inclusion body = A protein crystal that encloses an insect virus.
inclusive fitness = Net genetic representation of an individual in succeeding generations, through personal reproduction
and that of individuals bearing identical genes.
incomplete metamorphosis = Slight changes from molt to molt until wings and genitalia are fully formed in the adult.
indirect pest = A pest insect that feeds on a part of the plant that is not marketed.
infected = Applied to arthrops where a parasitic infection has been taken up by the vector but is not yet in a stage where
it can be transmitted to a host.
ingestive = Term applies when parasites are obtained at the time of feeding, the infective stage being gested through
inoculative = Term applied when invasion of an organism takes place through the act of biting, the organism being
inoculated during the feeding process.
insect growth regulator (IGR) = A substance produced by a plant that mimics or antagonizes an insect hormone.
insight learning = The ability to combine leamed behavior from diverse experiences to solve a problem.
instar = The stage of an insect's development between molts. Also, one of a series of life-cycle stages in metamorphosis that are
separated by a molt.
instinct = Behavior performed without previous experience and without interaction with other members of the species.
integrated pest management (IPM) = An approach to the control of pests (insects, diseases, weeds) in which all available
techniques are evaluated and integrated into a unified program (very difficult to administer).
integument = The cellular epidermis and outher non-cellular cuticle which together provide the outer covering of arthropods.
interference competition = Competition in which individuals are prevented from feeding, mating, or laying eggs as a result
of the presence of other individuals.
intermediate host = A host in which a parasite does not reach sexual maturity. Applies to most parasites in arthropod vectors.
Intermediate Host Reservoir = Hosts in which a natural supply of the sexual stage of a parasite occurs
interneuron = A nerve cell located within the central nervous system and serving to connect other neurons.
intersexual selection = Natural selection involving choices between the sexes, often on the basis of courtship displays.
intrasexual selection = Natural selection involving competition among members of one sex of a species, usually for mates.
intrinsic = Located entirely within an organ (as contrasted to extrinsic).
intrinsic incubation period = Duration of the life cycle of a parasite in the vertebrate host; interval between infection and
first clinical symptoms
ipsenol = An aggregation pheromone of bark beetles of the genus Ips.
Johnston's organ = A sense organ similar to a chordotonal organ, located in the second antennal segment of most insects;
this organ functions in sound perception in some Diptera. joint An articulation of two successive segments or
parts = An organ in the pedicel of the antenna, consisting of a cluster of chordotonal sensilla.
jugal lobe = A lobe at the base of the wing, on the posterior side, proximad of the vannal lobe (Hymenoptera). The
posterior area of the wing behind vein 1A and set off from more anterior areas by a slight fold (jugal fold) on
the wing and by a notch on the wing margin (also see claval lobe).
jugal vein = The most posterior of the major longitudinal vein systems according to Kukalova‑Peck. jugum A lobelike
process at the base of the front wing, which overlaps the hind wing (Lepidoptera); a sclerite in the head
(Hemiptera and Homoptera).
juvabione = An insect growth regulator occurring in certain trees and causing abnormal development of insects feeding
on the tree.
juvenile hormone (JH) = A hormone secreted by the corpora allata that maintains juvenile features in immature insects
and controls certain aspects of adult physiology and behavior.
kairomone = An interspecific chemical messenger that benefits the receiver but not the emitter.
karyotype = The number and appearance of the chromosomes in the nuclei of a species.
katepleurite = See catapleunte. keeled With an elevated ridge or carina.
kHz (Kilohertz) = kilocycles per second.
kin selection = Natural selection that involves inclusive fitness.
kinesis . An undirected movement in which the speed of movement or the frequency of tuming depends on the intensity
K‑strategist = A species characterized by a low reproductive rate, increased survival mechanisms, minor tendency to
disperse, and often a relatively large body size (as compared to an r‑strategist).
labellum (pl. labellae) = The expanded tip of the labium IDiptera; Iabial or pertaining to the labium.
Iabial gland = Exocrine organ opening on or at the base of the labium, usually functioning as salivary or silk gland.
Iabial suture = The suture on the labium between the postmentum and prementum.
Iabial palp = One of a pair of small feelerlike structures arising from the labium.
labium = One of the mouthpart structures, the lower lip.
Iabrum = The upper lip, Iying just below the clypeus.
Iabrum‑epipharynx = A mouthpart representing the labrum and epipharynx.
Iacinia (pl., laciniael) = The inner lobe of the maxilla, borne by the stipes.
Iamella = (pl., lamellae) A leaflike plate.
Iamellate = With platelike structures or segments; lamellate antennae.
Iamina = In the cuticle, a layer of cuticle with chitin microfibrils oriented in the same direction.
Iamina lingualis (pl., laminae linguales) = One of two median distal plates in the millipede gnathochilarium.
Ianceolate = Spear‑shaped, tapering at each end.
lanule = Crescent-shaped sclerite above base of antennae
Iarva (pl., larvae) = The immature stage, between egg and pupa, of an insect having complete metamorphosis; the
six‑legged first instar of Acari; an immature stage differing radically from the adult.
Iarviform = Shaped like a larva.
larviparous = Reproduction in which the egg or eggs hatch within the female and the larva or larvae are deposited.
Common in tsetse-flies.
Iaterad = Toward the side, away from the midline of the body.
Iateral = Of or pertaining to the side (that is, the right or left side).
Iateral oviduct = A tube in the female internal genitalia connecting the ovaries and the common oviduct.
Iaterotergite = A tergal sclerite located laterally or dorsolaterally.
Iateroventral = To the side laway from the midline of the body) and below.
Ieaf miner = An insect that lives in and feeds upon the leaf cells between the upper and lower surfaces of a leaf.
life cycle (syn: life history) = In entomology and parasitology this usually means the series of morphological stages an
organism passes through to reach the mature adult stage, and the biology of each stage.
Iigula = The terminal lobe (or lobej of the labium, the glossae and paraglossae.
Iinear = Line like, long and very narrow.
longevity = The length of time an organism lives, often expressed as the mean expectancy of life. Vector longevity is an
important factor in disease transmission dynamics and vector control.
Iongitudinal = Lengthwise of the body or of an appendage.
Iooper = A caterpillar that moves by looping its body, that is by placing the posterior part of the abdomen next to the
thorax and then extending the anterior part of the body forward; a measuringworm.
Iorum (pl., lora) = The cheek; a sclerite on the side of the head of Hemiptera and Homoptera; the submentum in bees.
Iuminescent = Producing light.
Iunule, frontal = See frontal lunule.
labium (adj., labial) = The posterior, medial appendage of the mouthparts between adn behind the maxillae, composed
of the submentum, emntum, prementum, glossa, paraglossa, and labial palpi. The third set of mouthparts of
insects (or underlip), located behind the maxillae.
labrum (adj., labral) = The anterior, medial appendage of the mouthparts attached to the underside of, and often
concealed by, the clypeus. A flaplike structure anterior to the mouthparts, kelow the clypeus.
lacina (pl., laciniae) = The inner apical lobe of the maxilla, articulated to the stipes.
lamina (pl., laminae; adj., laminate) = A thin plate or leaf-like process.
latent learning = Conditioning in which the reward occurs some time following receipt of the stimulus.
life table = A tabulation of the life stages of an insect with a cumulative record of mortality and survival.
light compass orientation = Orientation in which a constant angle with a light source (usually the sun) is maintained.
laterotergite = The lateral part of an abdominal/metasomal tergum that is marked by a crease or groove, or is even
completely detached from the main dorsal part of the tergum (also see tergite, tergum).
locustol = A primer pheromone of the desert locust that triggers development from the solitary to the gregarious form.
maggot = A vermiform larva; a legless larva without a well developed head capsule, thorax or abdomen (Diptera).
maintenance host = A vertebrate or arthropod host that allows long-term survival of a parasite population. The host must have
an infection rate that is at least adequate to maintain a population of the disease agent endemic in an area.
malar space = The shortest distance between the base of the mandible and the margin of the compound eye.
Malpighian tubules = Excretory tubes that arise near the anterior end of the hindgut and extend into the body cavity.
An excretory tubule, opening into the gut at the junction of the midgut and hindgut.
mandible (adj., mandibular) = Jaw; one of the anterior pair of paired mouthpart structures. One of the most anterior pair
of insect mouthparts, often jawlike and working from side to side. The paired, heavily sclerotized biting and
chewing lateral appendage of the mouthparts between the labrum and maxilla.
mandibulate = With jaws fitted for chewing.
marginal cell = A cell in the distal part of the wing bordering the costal margin (Diptera, Hymenoptera).
marginal vein = A vein on or just within the wing margin; the vein forming the posterior side of the marginal cell
margined = With a sharp or keellike lateral edge.
maxilla (pl., maxillae; adj., maxillary) = The paired appendage of the mouthparts between the mandible and labium,
consisting of the cardo, stipes, lacinia, galea, and maxillary palpus.
maxillary = Of or pertaining to the maxilla.
maxillary palp = A small feelerlike structure arising from the maxilla.
maxilliped = One of the appendages in Crustacea immediately posterior to the second maxillae.
maxilla = One of a pair of mouthparts behind the mandibles and before the labium, bearing the maxillary palpi.
mechanical transmission = Transmission where there is no multiplication or cyclical development of the aetiological agent
(i.e., parasite or pathogen), it being only passively carried by the vector.
mechanoreceptor = A sensillum sensitive to physical displacement =
media = The longitudinal vein between the radius and cubitus.
medial (or median) = Referring to the center, usually the midline, of an animal.
medial cross vein = A cross vein connecting two branches of the media.
median = In the middle; along the midline of the body.
medio‑cubital cross vein = A cross vein connecting the media and cubitus.
membrane = A thin film of tissue, usually transparent; that part of the wing surface between the veins; the thin apical
part of a hemelytron (Hemiptera).
membranous = Like a membrane; thin and more or less transparent lwingsi; thin and pliable lcuticle1.
mental setae = Setae on the mentum (Odonata).
mentum = The distal part of the labium, which bears the palps and the ligula; a median, more or less triangular piece in
the millipede gnathochilarium.
mentum = A labial sclerite articulating basally with the submentum and apically with the prementum; often fused with
the latter and indistinguishable as a separate sclerite.
merocrine secretion = Release of enzymes across the cell membrane, without destruction of the entire cell.
meroistic ovary = An ovary possessing nurse cells that are connected to or accompany the oocytes.
meroistic ovariole = Ovariole with nurse cells.
meropleuron (pl., meropleura) = A sclerite consisting of the meron lbasal part1 of the coxa and the lower part of the eplmeron.
The lateral and ventral part of the mesothorax (also see mesosternum)
mes-, meso- = A Greek prefix meaning middle or mid; used with Latin, latinized, or Greek words to indicate the middle
(often 2nd) part of a structure.
mesad = Toward the midline of the body. mesal At or near the midline of the body.
mesenteron = The midgut, or middle portion of the alimentary tract.
mesepimeron (pl., mesepimera) = The epimeron of the mesothorax.
mesepimeron = The posterior subdivision of the mesopleuron, usually small relative to the mesepisternum or almost
mesepisternal groove = A groove on the mesopleuron, extending ventrally from a pit under the base of the forewing
and, when complete, reaching the anteroventral margin of the mesothorax.
mesepisternum (pl., mesepisterna) = The episternum of the mesothorax = The anterior subdivision of the mesopleuron,
usually comprising most of the mesopleuron.
mesinfraepisternum = A ventral subdivision of the mesepisternum (Odonata).
meson = The midline of the body, or an imaginary plane dividing the body into right and left halves.
Mesonotal suture = Dorsal sclerite of mesothorax
mesonotum = The dorsal sclerite of the mesothorax.
mesothorax = The middle segment of the insect thorax.
mesopleural bristles = Bristles on the mesopleuron (Diptera).
mesopleuron (pl., mesopleura) = The lateral sclerite~s1 of the mesothorax; the upper part of the episternum of the
mesoscutal lobe = The mesoscutum is usually divided by the notauli into a medial part and two lateral lobes (also see
mesoscutellar appendage = In Symphyta, the posterior subdivision of the mesoscutellum, usually crescent-shaped and
overhanging the postnotum of the mesothorax.
mesoscutellum = The scutellum of the mesothorax, usually simply called the scutellum. The middle region of the m
esonotum or metanotum, behind the scutum = In Apocrita, only the mesoscutellum is evident and is simply
called the scutellum, while in Symphyta both the mesoscutellum and metascutellum are present.
mesoscutum = The scutum of the rnesothorax. In groups with a transscutal articulation, the portion of the mesonotum
anterior to the articulation; the mesoscutum is usually divided by the notauli into a medial part and two lateral
lobes (also see scutum).
mesosoma (pl., mesosomata; adj., mesosomal) = In Apocrita, the thorax plus the propoedum (cf. thorax) = In Apocrita
(Hymenoptera) the middle tagma of the body, composed of the three thoracic segments and the first true
abdominal segment Ithe propodeum).
mesosternum = The sternum of the mesothorax, usually invaginated and not visible, but sometimes incorrectly used as
a general term for the ventral surface of the mesothorax, such as when it is modified into a flattened plate with
posteriorly projecting lobes (also see mesopleuron) = The sternum, or ventral sclerite, of the mesothorax.
mesothorax = The middle or second segment of the thorax. The 2nd and largest of the 3 primary subdivision of the thorax,
bearing the middle pair of legs and, when present, the forewings.
mesotrochantinal plate = The ventral part of the mesothorax inflected towards the metasternum beneath the base of the
mesocoxae; visible only by removing the mesocoxae.
met-, meta- = A Greek prefix meaning "hind" or "posterior"; used with Latin, latinized, or Greek words to indicate the
posterior (usually 3rd) part of a structure.
metacyclic trypanosome = The final, and usually smaller, version of the trypomastigote form in the vector that is infective
for the vertebrate host.
metamere = A primary body segment lusually referring to the embryo).
metamorphosis = A change in form during development. Also, changes in form from the first stage (egg) in the life cycle of
an arthropod to the adult form. Rates of change differ among the species.
metanotum = The dorsal sclerite of the metathorax.
metapleuron = The lateral and ventral part of the metathorax.
metapneustic = Only two spiracles are retained at the posterior end of the body.
metascutellum = The scutellum of the metathorax.
metascutellum = In Symphyta, the middle region of the metanotum.
metasoma (pl., metasomata; adj., metasomal) = In Ap6crita (Hymenoptera) the posterior tagma of the body, comprised
of all segments posterior to the propodeum. = In Apocrita, the apparent abdomen, consisting of the abdomen
excluding the 1st segment or propodeum (cf. abdomen).
metasternum = The sternum of the metathorax, usually invaginated and not visible but sometimes used as a general term
for the ventral surface of the metathorax.
metatarsus (pl., metatarsi) = The basal segment of the tarsus.
metathorax = The 3rd of the three primary subdivision of the thorax, bearing the hind pair of legs and, when present,
the hind wings = The most posterior of the three segments of the thorax.
metazonite = The posterior portion of a mlllipede tergum when the tergum is divided by a transverse groove.
metepimeron (pl., metepimera) = The epimeron of the metathorax.
metepimeron = The posterior subdivision of the metapleuron.
metepisternum (pl., metepisterna) = The episternum of the metathorax.
metepisternum = The anterior subdivision of the metapleuron.
metinfraepisternum = A ventral subdivision of the metepisternum (Odonata).
microbial insecticide = Insecticide comprising a biological agent such as bacteria (e.g., Bacillus thuringiensis) or toxic
compounds derived from such agents.
micropile = A pore in the chorion through which sperm enter = A minute opening lor openings) in the chorion of an insect
egg, through which sperm enter the egg.
midgut = The mesenteron, or middle portion of the alimentary tract.
migration = A form of dispersal involving longdistance movements under at least partial control of the insects.
mimicry = Presence of a pattem in a palatable species that closely resembles the pattem of an unpalatable species
( = Batesian mimicry) (see also Mullerian mimicry).
millimeter = 0.001 meter, or 0.03937 inch (about ~s inch).
minute = Very small; an insect a few millimeters in length or less would be considered minute.
molt = A process of shedding the exoskeleton; ecdysis; to shed the exoskeleton.
molting gland = See prothoracic glands
molting hormone (MH) = See Ecdysone.
monoculture = A uniform stand of one kind of crop plant.
monecious = Possessing both male and female sex organs, hermaphroditic.
moniliform = Beadlike, with rounded segments; moniliform antenna.
monocondylic = A joint with a single point of articulation.
monophagous = Feeding on a single plant or animal species.
morphology = The science of form or structure. Also, the outward structure of an organism. Most arthropods are
identified by their morphology, that is by their outer appearance.
motor neuron = A neuron that forms a synapse with a muscle.
moulting = The process of shedding the cuticle between developmental stages of arthropods.
mouthparts = The appendages of the head used for feeding, including the labrum, hypopharynx, mandibles, maxillae,
Mullerian mimicry = Presence of a similar aposematic pattem in unrelated, distasteful or poisonous species.
multivoltine = Having several generations a year.
mushroom body = A complex fiber tract in the anterior part of the brain, often suggesting the shape of a mushroom,
associated primarily with the integration of sensory information .
mutualism = A living together of two species of organisms, with both species being benefited by the association.
myiasis = Invasion of vertebrate organs or tissues by larvae of Diptera that feed on living or deat tissues. Myiasis may
be accidental, obligatory or facultative.
mycetome = A specialized internal organ that houses symbiotic microorganisms.
mycoplasma = A pathogenic microorganism that passes through bacterial filters but has certain features in common with
myiasis = A disease caused by the invasion of dipterous larvae. Infestation with the maggots of flies.
myogenic flight muscles = Flight muscles that contract repeatedly as a result of mechanical stretch and do not require
a nervous impulse for each contraction.
myogenic = Produced by muscle; contraction of a muscle generated by that muscle itself, without neuronal stimulus.
myogenic rhythms = Rhythms produced by spontaneously active muscles.
myrmecophile = A symbiont found in the colonies of ants, usually living at the expense of the food in the nest.
myrmecophyte = A plant that has special cavities in which ants live.
myriapod . A many‑legged arthropod; a centipede, millipede, pauropod, or symphylan.
naiad = An aquatic, gill‑breathing nymph.
nasute soldier (or nasutus) = An individual of a termite caste in which the head narrows anteriorly into a snoutIike
natural control = The maintenance of a population at nonoutbreak levels by natural environmental factors, biotic and abiotic.
Nearctic Region = The United States, Canada, Greenland and northern Mexico.
nebulous vein = A wing vein that is uniformly pigmented (not darker on its margins), without a tubular structure; it can
be seen with both reflected and transmitted light (cf. spectral, tubular veins).
necrophagous = Feeding on dead animal matter.
nectar guide = A streak on a flower that guides insects to nectar sources.
neopterous = Possessing the ability to fold the wings backward over the abdomen.
Neotropical Region = South America, Central America, southern Mexico and Caribbean islands.
neural lamella = A fibrous, noncellular layer that surrounds and supports a ganglion.
neurogenic = Produced by a neuron; contractions of muscle stimulated by a neuronal impulse. nidi In the midgut, clusters
of regenerative epithelial cells.
neurogenic flight muscles = Flight muscles that contract each time a nerve impulse is received.
neurogenic rhythms = Rhythms maintained by spontaneously active neurons.
neurohemal organ = An organ associated with the nervous system that stores and releases hormones.
neuron = Nerve cell.
neuropile = The mass of closely packed nerve cell processes comprising the central part of a ganglion.
neurosecretory cell . A cell of the nervous system that is specialized for the production and release of hormones.
New World = North, Central and South America, and the Caribbean area.
niche = The role that a species occupies in nature; that is, its precise habitat plus its behavior in that habitat.
nidicolous = In medical entomology often used to describe the habit of soft and some hard ticks of living in and around the
homes, nests, burrows and caves of their hosts. Such ticks disperse very little.
nocturnal = Active at night. Refers to activity during the night, such as blood-feeding in anopheline mosquitoes and the
appearance in vertebrate blood of nocturnally periodic microfilariae of some helminths.
node = A knoblike or knotlike swelling.
nodilorm = In the form of a knob or knot.
nodus = A strong cross vein near the middle of the costal border of the wing (Odonata).
notal wing process = Point at which the notum articulates with the wing (or axillary sclerites at the base of the wing).
notaulus (pl., notauli) = The usually oblique, longitudinal groove on the mesoscutum, often dividing the mesoscutum
into medial and lateral parts = A longitudinal line on the mesoscutum of Hymen6ptera, marking the separation
of the dorsal longitudinal and dorsoventral flight muscles; also sometimes called notaulix notaulices),
parapsidal furrow, or parapsidal suture.
notopleural bristles = Bristles on the notopleuron (Diptera).
notopleural suture = A groove separating the mesonotum from the mesopleuron = A suture between the notum and the
notopleuron (pl., notopleura) = An area on the thoracic dorsum, at the lateral end of the transverse suture (Diptera).
notum (pl., nota; adj., notal) = A thoracic tergum, usually subdivided into a scutum and a scutellum = A dorsal sclerite
of the insect thorax = The dorsal sclerite of a thoracic segment; the fused second gonapophyses of the
nuclear polyhedrosis virus (NPV) = A vinus that multiplies in cell nuclei, chiefly in the epidermis, fat body, and blood cells.
nurse cells = Nutritive cells associated with the developing oocyte.
nymph = An immature stage (following hatching) of an insect that does not have a pupal stage; the immature stage of
Acari that has eight legs.
oblique scutal carina = In Spheciformes, the ridge on the mesoscutum extending obliquely posteriorly and medially
from the lateral margin near the posterior of the tegula.
oblique vein = A slanting cross vein; in Odonata, where Rs crosses M, 2.
obtect pupa = A pupa in which the appendages are more or less glued to the body surface, as in the Lepid6ptera.
occipital carina = A ridge on the posterior surface of the head that separates the occiput from the vertex and gena; the
ventral part of the ridge is sometimes called the genal carina.
occipital foramen = See foramen magnum.
occipital suture (or sulcus) = A transverse suture in the posterior part of the head that separates the vertex from the
occiput dorsally and the genae from the postgenae laterally.
occiput (adj., occipital) = The posterior part of the head behind the vertex dorsally and teh genae laterally. If an occipital
carina is present, the occiput is the area betwen it and the very narrow postocciput surrounding the foramen
magnum (also see postgena). The dorsal posterior part of the head, between the occipital and postoccipital
ocellar bristles = Bristles arising close to the ocelli (Diptera).
ocellar triangle = A slightly raised triangular area in which the ocelli are located (Diptera).
ocellus (pl., ocelli) = A simple eye on the dorsal part of the head, containing a single facet = Hymenoptera usually have
three ocelli: one median (anterior) and two lateral (posterior).
Old World = All countries and aras east of the Americas.
olfaction = The sense of smell; the ability to detect chemicals in a gas.
oligolectic = Utilizing a very limited number of plant species as sources of pollen (said chiefly of bees).
oligophagous = Feeding on a somewhat restricted group of (often related) plant or animal species.
olistheter = A tongue‑in‑groove mechanism connecting the first and second gonapophyses of the ovipositor.
ommatidium (pl., ommatidia) = A functional unit of the compound eye, expressed extemally as a facet. A single unit
or visual section of a compound eye.
onisciform larva = See platyform larva.
oocyte = Egg.
oocyst rate = the percentage of mosquitoes that have malarial oocysts on the stomach.
oogenesis = The production of eggs.
oogonium (pl., oogorlia) = The primary germ cells of the female.
ootheca = A hardened protective structure surrounding the egg mass, composed of tanned protein and secreted by
accessory glands. The covering or case of an egg mass IMantodea, Blattaria.
open coxal cavity = One bounded posteriorly by a sclerite of the next segment (front coxal cavities, Coleoptera), or one
touched by one or more pleural sclerites (middle coxal cavities, Coleoptera).
open cell = A wing cell extending to the wing margin, not entirely surrounded by veins.
operculum (pl., opercula) = A lid or cover.
opisthognathous = With the mouthparts directed backward.
opisthorhynchous = With the beak directed backward
oral = Pertaining to the mouth.
oral cavity = The opening of the head from which the mouthparts are suspended.
oral vibrissae = A pair of stout bristles, one on each side of the face near or just above the oral margin, and larger than
the other bristles on the vibrissal ridge (Diptera).
orbit = The narrow border around the eye = The inner and outer orbits are those parts of the face plus the frons and the
gena, respectively, immediately next to the eye.
orbital plate = An area on the head above the antenna and next to the compound eye (Diptera); also called genovertical plate.
order = A subdivision of a class or subclass, containing a group of related superfamilies or families.
Oriental Region = Asia east of Pakistan and south of the Himalayas and central China, covering Taiwan, Sri Lanka, & the
southeast Asia archipelago eastwards to include Sulawesi.
ornithophagic = Arthropods that feed on the blood of birds.
orthognathous = With mouth directed ventrad
osmeterium (pl., osmetena) = A fleshy, tubular, eversible, usually Y‑shaped gland at the anterior end of certain
caterpillars (Papilionidae). An eversible gland on the thorax of the larvae of swallowtail butterflies that
osmoregulation = The regulation of water balance in arthropods; maintaining the homeostasis (balance) of osmotic
and ionic content of body fluids.
ostia = Segmentally arranged inlet pores in the walls of the heart.
ostiole = A small opening.
ostium (pl., ostia) = A slitlike opening in the insect heart.
outer vertical bristles = The more laterally located of the large bristles on the vertex, between the ocelli and the
compound eyes (Diptera).
ovariole = One of the tubules making up the ovary, in which the eggs are formed = A more or less tubular division of an
overwintering = Describes the survival tactics of arthropods during winters. Examples include some mosquitoes that cease
feeding and ovipositing and enter a state of hibernation until warmer weather reappears and activitiy resumes.
ovipositor = The egg‑laying apparatus of insects, typically composed of two sets of valves or a tubular extension of the
ovisorption = Resorption of eggs prior to the time of oviposition.
ovoviviporous = Producing small larvae, the eggs having hatched inside the mother.
ovary = The egg‑producing organ of the female.
oviduct = The tube leading away from the ovary through which the eggs pass.
oviparous = Laying eggs.
ovipore = The external opening of the female reproductive system through which the eggs pass during oviposition.
oviposit = To lay or deposit eggs.
ovipositor = The egg‑laying apparatus; the external genitalia of the female. In females, a slender, paired and interlocking, saw-like
or tubular structure used for laying the eggs or, in Aculeata, for stinging or, in some Ichneumonoidea, for both; it may
be concealed or may extend beyond the apex of the body and is protected by a pair of ovipositor sheaths.
ovipositor sheath = A paired, slcerotized structure enclosing the external part of the ovipositor =
oviscapt = Modification of the terminal abdominal segments of a female to serve as an egg‑laying organ.
paedogenesis = Reproduction by larviform individuals; production of eggs or young by an immature or larval stage of an animal.
Palaearctic Region = Europe, North Africa, Saia north of the Himalayas and central China, Japan, Iceland, and
paleopterous = Lacking the ability to position the wings backward over the abdomen.
palp = A segmented process born by the maxillae or labium.
palpifer = The lobe of the maxillary stipes that bears the palp.
palpiform = Segmented process
palpiger = The lobe of the mentum of the labium that bears the palp.
palpus (pl., palpi; adj., palpal) = Paired sensory appendages of the maxilla and labium, consisting of 1-6 segments and
1-4 segments, respectively.
panoistic ovariole = Ovariole without nurse cells.
panoistic ovary = An ovary in which the ovarioles lack nurse cells.
papilla = A small nipple like elevation.
paraglossa (pl., paraglossae) = A paired, lateral lobe of the labium articulated basally with the prementum lateral to the base of
the glossa = One of a pair of lobes at the apex of the labium, laterad of the glossae.
paramere = A structure in the male genitalia of insects, usually a lobe or process at the base of the aedeagus.
paranotum = Lateral expansion of the notum.
paraproct = One of a pair of lobes bordering the anus lateroventrally.
parasite = An animal that lives in or on the body of another living animal (its hostl, at least during a part of its life cycle, feeding
on the tissues of its host; most entomophagous insect parasites kill their host (see parasitoid )
parasitic = Living as a parasite.
parasitoid = An animal that feeds in or on another living animal for a relatively long time, consuming all or most of its tissues
and eventually killing it (also used as an adjective, describing this mode of life). Parasitoid insects in this book are
referred to as parasites. An insect that lives in its immature stages in or on another insect, which it kills after completing
its own feeding.
parental investment = Behavior of a parent that increases the probability of offspring survival at the cost of the parent's ability
to produce more offspring.
parthenogenesis = Development of the egg without fertilization. Production of young from unfertilized eggs.
patella = A leg segment between the femur and tibia (arachnids).
paurometabolous = With simple metamorphosis, the young and adults living in the same habitat, and the adults winged.
pecten = A comblike or rakelike structure.
pectinate = Comblike; that is, having a series of slender projections from an elongate shaft. With branches or processes like
the teeth of a comb; pectinate antenna; pectinate tarsal claw.
pedicel = The 2nd primary division or segment of the antenna; it articulates apically with the flagellum and basally with the
scape. The second, usually small, segment of the antenna; the stem of the abdomen, between the thorax and the
pedipalps = The second pair of appendages of an arachnid.
pedunculate = An intermediate, club-like condition between sessile and petiolate (also see petiolate).
pelagic = Inhabiting the open sea; ocean‑dwelling.
penultimate = Next to the last.
pericardial sinus = A space around the heatt, limited below by the dorsal diaphragm. The body cavity surrounding the dorsal
blood vessel, limited ventrally by the dorsal diaphragm.
perineural sinus = The body cavity surrounding the ventral nerve cord, limited dorsally by the ventral diaphragm.
perineurium = The layer of cells surrounding a ganglion, which secretes the neural lamella.
periodicity = Several organisms, including both vectors and parasites, exhibit temporal periodicity in aspects of their behavior.
peripneustic = Lateral spiracles on the abdomen.
peristalsis = Waves of contraction.
peristome = The ventral margin of the head, bordering the mouth.
peritrophic membrane = A membrane in insects secreted by the cells lining the midgut; this membrane is secreted when food is
present and forms an envelope around the food; it usually pulls loose from the midgut, remains around the food, and
passes out with the feces.
perivisceral sinus = The body cavity surrounding the digestive system, reproductive system, etc., between the dorsal and
petiolate = Attached by a narrow stalk or stem. Stalked, drawn out into an extended process.
petiole = Part of the metasoma, usually metasomal segment 1; the usually narrow, parallel-sided stalk joining the rest of the
metasoma to the propodeum.
pH = A measure of the acidity or alkalinity of a medium. A pH value of 7.0 indicates neutral; lower values indicate acid, and
higher values alkaline. Defined as ‑log IH~I.
phagostimulant = A natural plant substance that induces feeding by an insect.
phallotreme = External opening of the male reproductive system on the aedeagus.
phallus = The male copulatory organ, including any processes that may be present at its base.
pharate stage = A stage in which molting has occurred but the insect has not cast off the old cuticle.
pharynx = A muscular portion of the foregut, just behind the mouth. The anterior part of the foregut, between the mouth
and the esophagus.
phenological asynchrony = Lack of synchrony between the life cycle of a pest and the appropriate stage of its host plant.
pheromone = A substance given off by one individual that causes a specific reaction by other individuals of the same species,
such as sex attractants, alarm substances, etc.
phoresy = A condition in which an individual is carried about by another individual without harming that individual.
photoperiod = The relative amount of time during
phragma (pl., phragmata) = A plate like apodeme or invagination of the dorsal wall of the thorax.
phylogeny = The study of the history of lines of evolution .
phylum (pl., phylal) = One of the dozen or so major divisions of the animal kingdom.
physical gill = A bubble or packet of air that adheres to the body of an aquatic insect and is continuous with the tracheal
phytoecdysone = A plant product that mimics ecdysone.
phytophagous = Feeding on plants.
phytotoxemia = A diseaselike plant condition produced by the injection of toxic substances by insects.
pictured = With spots or bands (pictured wings.
pilifer = One of a pair of lateral projections on the labrum (Lepidoptera).
pilose = Covered with hair.
placoid sensillum (pl., placoid sensilla) = An elongated, appressed, plate-like or rounded roof-like or groove-like
planidium larva = A type of first‑instar larva in certain Diptera and Hymenoptera that undergoes hypermetamorphosis;
a larva that is legless and somewhat flattened.
plantar lobe = A small membranous pad projecting from the ventral apex of tarsomeres 1-4.
plastron = A framework of stiff, water‑repellent hairs or cuticular structures on the bodies of aquatic insects, containing a film
of air into which oxygen diffuses from the water.
platyform larva = A larva that is extremely flattened, as the larva of Psephenidae; also called onisciform larva.
pleural = Pertaining to the pleura, or lateral sclerites of the body; lateral.
pleural apophysis (or arm) = Internal process extending from the pleural suture to the sternal apophyses. Pleural suture
(or sulcusl A suture of a thoracic pleuron extending from the base of the wing to the base of the coxa, which separates
the episternum and epimeron.
pleural groove = A groove on the mesopleuron and metapleuron extending between the wing base and the coxal articulation;
it separates the episternum from the epimeron.
pleural suture = A vertical or oblique suture marking an intemal ridge of the thoracic pleuron, running from the dorsal coxal
articulation to the pleural wing process.
pleural wing process = A fulcrum for the wing base, formed at the top of the intemal ridge fommed by the pleural suture.
pleurite = A lateral or pleural sclerite.
pleuron (pl., pleura; adj., pleural) = The lateral part of a body segment, usually of a thoracic segment where the pleuron
occupies the lateral as well as the ventral areas of the mesothorax and metathorax.
pleuropodium = Embryonic appendages of the first abdommal segment.
pleurotergite. A sclerite containing both pleural and tergal elements.
plicae = folds
plumose = Featherlike; plumose antenna.
podite = A segment of an arthropod leg, moved by muscles inserted in its base.
poikilothermous = Cold‑blooded, the body temperature rising or falling with the environmental temperature.
point = A small triangle of stiff paper, using in mounting small insects.
pollen basket = See corbicula.
pollen rake = A comblike row of bristles at
polyculture = A mixed stand of crop plants.
polyembryony = Division of a single egg to form several identical embryos. An egg developing into two or more embryos.
polyethism = The presence of several discrete types of behavior by different groups of individuals in colonies of social insects.
polylectic = Utilizing a variety of plant species as sources of pollen.
polymorphism = The presence of two or more distinct, structurally different types of individuals within the same stage of one species.
Polynesia = A group of numerous islands in the western Pacific extending from Hawaii to New Zealand and including the
Solomon Islands, New Caledonia, Fiji, Tuvatu, Tonga, Samoa, Cook Islands, Society Islands and Tahiti.
polyphagous = Feeding on a broad array of plant or animal species.
polytene chromosomes = The giant chromosomes found only in certain tissues of Diptera, such as the ovarian nurse cells of
half-gravid anophelines and larval salivary glands of simulids.
polytrophic ovariole = Meroistic ovariole in which trophocytes pass into the vitellarium with the oocyte.
population dynamics = The forces that control population size, and their effects.
population regulation = The maintenance of an almost constant population size and density, and the forces that control it.
population resilience = The capacity of a population to adapt to change or to persist in a changing environment.
population stability = The ability of a population to absorb disturbance and to return to an equilibrium state.
porrect = Extending forward horizontally; porrect antennae.
postabdomen = The modified posterior segments of the abdomen, which are usually more slender than the anterior segments
(Crustacea); see also the postabdomen in a scorpion.
postalar callus = A rounded swelling on each side of the mesonotum, between the base of the wing and the scutellum (Diptera).
posterior = Hind or rear.
posterior cell = One of the cells extending to the hind margin of the wing, between the 3rd and 6th longitudinal veins (Diptera).
posterior cross vein = A cross vein at the apex of the discal cell (Diptera)
posterior lingual plate = A sclerite on the posterior (ventral) surface of the glossa.
postgena (adj., postgenal) = The lower part of the occiput; when the occipital carina is absent, the gena and postgena are c
ontinuous, and the entire lower area constitutes the gena (also see occiput).
postgena (pl., postgenae) = A sclerite on the posterior lateral surface of the head, posterior to the gena.
postgenal bridge = Mesal extension of the postgenae on each side to meet below the foramen magnum.
posthumeral bristles = Bristles on the anterolateral surface of the mesonotum, just posterior to the humeral callus (Diptera).
postmarginal vein = The vein along the anterior margin of the front wing, beyond the point where the stigmal
vein arises (Hymen6ptera),
postmentum = The basal portion of the labium, proximad of the labial suture.
postnodal cross veins = A series of cross veins just behind the costal margin of the wing, between the nodus and stigma, and
extending from the costal margin of the wing to Rl (Odonata).
postnotum (pl., postnota) = A notal plate behind the scutellum bearing a phragma, often present in wing‑bearing segments,
A posterior sclerite of the mesonotum and metanotum behind the scutellum = The postnotum of the metathorax is fused
dorsally with abdominal tergum 1 and laterally with the metepimeron; in Apocrita the postnotum is seldom visible,
and then only as an impressed line in front of the propodeum.
postoccipital suture = The transverse suture on the head immediately posterior to the occipital suture.
postocciput (adj., postoccipital) = A narrow area surrounding the foramen magnum; it is separated from the occiput by the
postoccipital groove = The extreme posterior rim of the head, between the postoccipital suture & the foramen magnum.
postpectal carina = In Ichneumonoidea, the posterior transverse carina ventrally on the mesopleuron.
postpetiole = The second segment of a two‑segmented pedicel jantsl.
postscutellum = A small transverse piece of a thoracic notum immediately behind the scutellum, in Diptera, an area just
behind or below the mesoscutellum.
postvertical bristles = A pair of bristles behind the ocelli, usually situated on the posterior surface of the head (Diptera).
preapical = Situated just before the apex; preapical tibial bristles of Diptera.
prebasilare = A narrow transverse sclerite, just basal to the mentum in the gnathochilarium of some millipedes.
precoccinelline = A defensive allomone produced by lady beetles during autohemorrhage.
precocene = An insect growth regulator produced by certain plants that depresses the source of juvenile hormone.
precosta = The most anterior of the major longitudinal wing veins laccording to Kukalova‑Peckl.
predaceous = Feeding as a predator.
predator = An animal that attacks and feeds on other animals (its prey), usually animals smaller or less powerful than itself.
The prey is usually killed and mostly or entirely eaten; each predator eats many prey individuals.
prefemur = The second trochanter segment of the leg.
pregenital = Anterior to the genital segments of the abdomen.
preimaginal conditioning = Conditioning of an immature insect that persists into the adult stage.
prementum = A labial sclerite that articulates basally with the mentum and bearing the glossae, paraglossae, and palpi apically.
The distal part of the labium, distad of the labial suture, on which all the labial muscles have their insertions.
preoral = Anterior to or in front of the mouth.
prepectus = A sclerite of the thorax between the pronotum and the mesepisternum (also see epicnemium). An area along
the anteroventral margin of the mesepisternum, set off by a suture (Hymenoptera)
prepupa = A quiescent stage between the larval period and the pupal period; the third instar of a thrips. A resting stage of the
last larval instar, prior to the molt to the pupal stage.
prestigma = The enlarged and sclerotized apex of one or more veins on the anterior margin of the wing basal to the costal notch
and almost continuous with the stigma.
presutural bristles = Bristles on the mesonotum immediately anterior to the transverse suture and adjacent to the notopleuron (Diptera).
pretarsus (pl, pretarsi) = The terminal segment of the leg, typically consisting of a pair of claws and one or more padlike structures.
primary defense = A defense mechanism that is continuously present, such as crypsis.
primer pheromone = A pheromone that acts to modify the phvsiological state of an animal.
pro- = A Latin prefix meaning "before" or "anterior"; used with Latin, latinized, or Greek words to indicate the anterior
(usually 1st) part of a structure.
proboscis = The extended beaklike mouthparts.
proclinate = Inclined forward or downward.
proctodaeum . The hindgut, or the hindmost of the three major divisions of the alimentary tract, from the Malpighian tubules
to the anus.
procuticle = The inner zone of the insect cuticle, containing chitin and protein, divisible into exocuticle and endocuticle.
produced = Extended, prolonged, or projecting.
proepimeron (pl., proepimeral) = The epimeron of the prothorax.
proepisternum (pl., proepisterna) = The episternum of the prothorax.
profile = The outline as seen from the side or in lateral view.
prognathous = With the head somewhat in the same plane as the body (horizontal) so the mouthparts are directed
anteriorly (cf. hypognathous).
progressive provisioning = The supplying of food to the offspring over time, as the offspring grow.
proleg = A fleshy, unjointed "false leg," occurring ventrally on the abdomen of caterpillars and other larval insects.
One of the fleshy abdominal legs of certain insect larvae.
promastigote (leptomonad) = Morphological form of a trypanosomatid with the flagellum arising near the anterior
end (e.g., Leishmania parasites in the phelebotomine sandfly gut.
prominence = A raised, produced, or projecting portion.
prominent = Raised, produced, or projecting.
promote = To move anteriorly.
pronate = To turn the leading edge of the wing downward.
pronotal collar = The horizontal surface of the posterior to the sloping, & often narrowing, region just behind the head.
pronotal comb = A row of strong spines borne on the posterior margin of the pronotum (Siphonaptera).
pronotal flange = The anterior projected rim of the pronotum; it is often hidden by the head.
pronotal lobe = The rounded posterolateral extension of the pronotum that covers the mesothoracic spiracle.
pronotal plate = In Cynipoidea, the dorsal disc of the pronotum.
pronotum (adj., pronotal) = The dorsal sclerite of the prothorax; in most Hymenoptera, occupying also the dorsolateral
or lateral part of the prothorax. The dorsal, often shieldlike sclerite of the prothorax.
propleural bristles = Bristles located on the propleuron (Diptera).
propleuron (pl., propleura) = The lateral part of the prothorax = In Hymenoptera, it is displaced a bit by the pronotum so as to
occupy an oblique position ventrolateral and anterior to the pronotum.
propneustic = Lateral spiracles on the thorax.
propodeal carina = In Ichneumonoidea, one or more, usually distinct, transverse or longitudinal ridges on the propodeum.
propodeum (adj., propodeal) = In Apocrita, the first tergum of the abdomen, widely and immovably fused with the metanotum
and with each metapleuron of he thorax, and usually narrowly and flexibly joined to the rest of the abdomen
(also see abdomen, metasoma, thorax) = The posterior portion of the thorax, hich is actually the first abdominal
segment united with the thorax (Hymenoptera, suborder Apocrita).
proprioception = Detection by an animal.
proprioreceptor = A sense organ that detects the relative position of parts of an animal's own body.
prosoma = A term referring to the anterior part of the body, usually applied to the cephalothorax; the anterior part of
the head or cephalothorax.
prosternum = A ventral sclerite of the prothorax, between the propleura = The sternum, or ventral sclerite, of the prothorax.
protelean parasite = An entomophagous insect that attacks its prey only when the attacking insect is immature, the adult being
prothoracic glands = Endocrine organs located in the prothorax of immature insects, secreting molting hormone. Also
endocrine glands located in the prothorax generally that secrete ecdysone.
prothoracicotropic hormone (PTTH) = A hormone secreted by neurosecretory cells of the brain and serving to activate
the prothoracic glands.
prothorax = The first of the 3 primary subdivisions of the thorax, composed of the pronotum, the propleuron, and the
prosternum. Also, the anterior of the three thoracic segments.
protocerebrum = The largest and most anterior part of the brain, which includes the optic lobes = The dorsal lobes of the brain
innervating linter alial the compound eyes and ocelli.
protonymph = The second instar of a mite.
proventriculus = The portion of the foregut, just before the midgut, that controls entry of food into the midgut; often lined with
sclerotized teeth that grind the food = The valve between the foregut and midgut.
proximal = Nearer to the body or to the base of an appendage = Referring to the part of an appendage that is closest to the body.
prozonite = The anterior portion of a millipede tergum when the tergum is divided by a transverse groove.
pruinose = Covered with a whitish waxy powder.
pseudarolium (pl., pseudarolial) = A pad at the apex of the tarsus resembling an arolium.
pseudocercus (pl., pseudocerci) = See urogomphi.
pseudocubitus = A vein appearing as the cubitus, but actually formed by the fusion of the branches of M and Cu, (Neuroptera).
pseudomedia = A vein appearing as the media, but actually formed by the fusion of branches of Rs (Neuroptera).
pseudopod (= "false leg") = Stumpy protuberance present on dipterous larvae of some species of Tabanidae.
pseudopupa = A coarctate larva; a larva in a quiescent pupalike condition, one or two instars before the true pupal stage
pseudotracheae = Small tubes in the labella of some adult Diptera (e.g., Muscidae, Calliphoridae, Tabanidae), which are
supported by sclerotized rings. Liquid food passes thru' minute openings in these pseudotracheae to the fly's mouth.
pseudovipositor = See oviscapt.
pteralia = See axillary sclentes.
pteropleural bristles = Bristles on the pteropleuron (Diptera).
pteropleuron (pl., pteropleura) = A sclerite on the side of the thorax just below the base of the wing, and consisting of the upper
part of the mesepimeron (Diptera).
pterostigma = A thickened opaque spot along the costal margin of the wing, near the wing tip lalso called the stigmal (Odonata).
pterothorax = The wing‑bearing segments of the thorax (mesothorax and metathoraxl.
pterygote = A winged insect, or a wingless insect believed to have been derived from winged ancestors. Winged; a member of
the subclass Pterygota.
ptilinum = A temporary bladderlike structure that can be inflated and thrust out through the frontal lor ptilinal~ suture,
just above the bases of the antennae, at the time of emergence from the puparium (Diptera) See brain hormone.
pubescence = The short, fine, often closely set setae on the body.
pubescent = Downy, covered with short fine hairs.
pulvilliform = Lobelike or padlike; shaped like a pulvillus; pulvilliform empodium.
punctate = Having fine, impressed points or pits.
punctiform = With impressed pits or depressions)
puncture = A tiny pit or depression.
pupa (pl., pupae) = The stage between the larva and the adult in insects with complete metamorphosis, a nonfeeding and usually
an inactive stage.
pupariation = Formation of the puparium by larvae of Diptera.
puparium (pl., puparia) = A case formed by the hardening of the last larval skin, in which the pupa is formed. Also: Life stage
resulting from the hardening of the cuticle of the last larval instar of some Diptera (e.g., tsetse-flies, houseflies)
pupate = To transform to a pupa.
pupiparous = Giving birth to larvae that are full grown and ready to pupate.
pygidial plate = A specialized area of the tergum of the last externally visible segment of the metasoma; it is usually flattened
and defined laterally by ridges or grooves.
pygidium = The last dorsal segment of the abdomen.
pyloric valve = The valve between the midgut and hindgut.
quadrangle = A cell immediately beyond the arculus (Odonata, Zygoptera)
quadrate = Four‑sided.
qualitative defenses of plants = Toxins and small‑molecular‑weight compounds (such as alkaloids) that are active against the
physiological systems of phytophagous insects = Complex, digestibility‑reducing substances (such as tannins) that reduce
the ability of insects to feed on plants.
queen substance = A pheromone produced by the queen honey bee and serving various functions in the hive as well as during
mating and swarming flights.
questing = The behavior of ticks, mainly Ixodidae, when climbing up vegetation, such as grasses & herbaceous plants in order
to seek out passing hosts, to which they attach themselves.
quiescence = A temporary stage of arrested or slowed development, such as in Ixodidae tick larvae after blood-feeding but prior
to molting to the nymphal stare of some hibernating dult mosquitoes.
radial cell = A cell bordered anteriorly by a branch of the radius; the marginal cell (Hymen6ptera)
radial cross vein = A cross vein connecting Rl and the branch of the radius immediately behind it.
radial sector = The posterior of the two main branches of the radius.
radicle = The basal part of the scape often strongly defined by a constriction; it articulates with the torulus.
radius = The longitudinal vein between the subcosta and the media.
raptorial = Fitted for grasping prey; raptoriai front legs.
reaction chain = A continuous series of behavioral acts, each of which is dependent on completion of the preceding act.
reclinate = Inclined backward or upward.
rectal pad = A portion of the rectum containing enlarged cells, responsible for active water and ion uptake from the
contents of the rectum.
rectum = The posterior region of the hindgut.
recumbent = Referring to a seta lying parallel to the body surface.regulatory control The use of enforceable regulations
to prevent the spread of a pest or to suppress or eradicate it.
recurrent vein = One of two transverse veins immediately posterior to the cubital vein (Hymenoptera); a vein at the base
of the wing between the costa and the subcosta, extending obliquely from the subcosta to the costa
recurved = Curved upward or backward.
releaser = An environmental or communicative stimulus that triggers a fixed action pattern.
releaser pheromone = A pheromone that acts via the central nervous system to produce a quick behavioral response.
releasing mechanism = An innate capacity to respond in a particular way to a specific stimulus.
remote = To move posteriorly =
reniform = Kidney‑shaped.
reservoir host = An animal in which populations of disease organisms persist indefinitely, and which passes the disease to
other species of hosts, often by vectors.
resilin = A rubberlike, proteinaceous constituent of the insect procuticle.
resting potential = The slight charge that can be measured in an unstimulated nerve cell.
reticulate = Covered with a network of lines; meshed or webbed. Like a network.
retina = The receptive apparatus of an eye.
retinula cell = A monopolar sensory neuron within an ommatidium of the compoun‑l eye.
retractile = Capable of being pushed out and drawn back in.
rhabdom = The central, rodlike element in an ommatidium, consisting of several rhabdomeres, one from each retinula
cell. A rodlike light‑sensitive structure formed of the inner surfaces of adiacent sensory cells in the omma
tidium of a compound eye.
Rickettsiae = A group of Gram-negative intracellular coccoid-shaped bacteria, many of which are transmitted by arthropods.
These were once regarded as microorganisms intermediate between bacteria and viruses.
Riker mount = A thin glass‑topped exhibition case filled with cotton.
rostrum = Beak or snout.
round dance = A torm of recruitment in the honey bee, used when a food source close to the hive is communicated to
royal jelly = A nutritive substance produced by glands in the heads of worker honey bees and fed to the larvae. Larvae
fed this diet throughout development produce queens.
r‑strategist = A species characterized by having rapid development, high motility, and a high reproductive rate relative
to a K‑strategist .
rudimentary = Reduced in size, poorly developed, embryonic.
rugose = wrinkled.
saprophagous feeding = on dead or decaying plant or animal materials, such as carrion, dung, dead logs, etc.
saprophagous = Feeding on dead organic matter.
scape = The most basal segment of the antenna = The first primary division or segment of the antenna; it articulates
apically with the pedicel and basally with the torulus.