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Keys to the Families & Subfamilies of Nearctic Chalcidoidea

Nearctic Area:

(Derived fr. Grissell & Schauff, 1990 by E. F. Legner)

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[Please refer to <Guide> for illustrations (Powerful connections use <Guide-2>)]

 

1a.    Hind femur enlarged, with ventral teeth, either a few large or many small ones (saw-like); hind tibia subequal

     to femur and arched; specimens usually 5-15 mm, stout bodied, rarely <1-2 mm .................................................2

 

1b.    Hind femur not enlarged, ventral denticles, if present, 2 or less, or ventral edge serrate; hind tibia straight

     (rarely half length of femur); specimens usually 1-10 mm., stout to fragile ..........................................................6

 

2a.    Prepectus reduced or fused, not readily apparent, of if so, not triangular in outline...........................................3

 

2b.    Prepectus apparent as a triangular plate..............................................................................................................5

 

3a.    Ovipositor directed horizontally [in most species not extended beyond apex of metasoma (gaster)]; tegula

almost an oval disc; fore wing not folded longitudinally ......................................................Chalcididae...4

 

3b.    Ovipositor curved dorsally over metasoma (gaster); tegula narrowly extended forward; fore wing often folded

longitudinally...............................................................................................................................Leucospidae

 

4a.    Frons projects as 2 "horns" (surrounding antennae) in dorsal view.....Chalcididae ........................(Dirhininae)

 

4b.    Frons not modified as "horns," mostly flat in dorsal view; hind tibia squarely truncate at apex; 2 hind tibial

spurs.................................................................................................................Chalcididae  (Haltichellinae)

 

4c.    Frons not modified as "horns," mostly flat in dorsal view; hind tibia obliquely truncate at apex; either 1 hind

tibial spur or spur not apparent.............................................................................Chalcididae  Chalcidinae)

 

5a.    Eyes diverge ventrally; antennae inserted low on face; ovipositor not exserted .........Pteromalidae  (Chalcedectini: Cleonyminae)  (part)

 

5b.    Eyes nearly parallel; antennae inserted near middle of face; ovipositor exserted .......................... Torymidae  (Podagrionini: Monodontomerinae)  (part)

 

6a.    Antennae with 5-7 segments between pedicel and club; tarsi usually with 5 segments (if with 4, then males of

Tetracampidae, or tiny specimens with long antennae and characteristic wings, (see Mymaridae illustration)  7

 

6b.    Antennae with 0-4 segments between pedicel and club; tarsi with 3, 4, or 5 segments; or specimens 0.2-1 or 2

mm. long and such characters hard to see (many tiny fragile specimens)...................................................40

 

7a.    Hind wing without stalk, expanded as shown; forewing venation ends beyond basal 1/3rd (postmarginal

present, stigmal elongated to sessile); specimens usually >2 mm ..................................................................9

 

7b.    Hind wing stalked and elongated (rarely reduced to only a short stub, hooked at tip); fore wing venation linear,

ending in basal 1/3rd (postmarginal absent, stigmal rudimentary), or apparently absent; specimens usually <2 mm

......................8

 

8a.    Abdominal petiole with 2 segments; fore wing reticulate (rare in North American collections) ......................

................................................... Mymarommatidae

 

8b.    Abdominal petiole with 1 segment or none; fore wing membrane smooth (common in North American

collections).......................................................................... Mymaridae

 

9a.    Mesopleuron concave; midtibial spur thin and like a spine...............................................10

 

9b.    Mesopleuron convex (bulging); midtibial spur relatively thick..........................................36

 

10a.    Head projects forward, female mandible with rasplike appendage; at least hind tibia shorter than femur; male

wingless (much modified); collected from fig fruits ................................................Agaonidae

 

10b.    Head projects downward, female without appendage on mandible; hind tibia at least as long as femur, usually

longer; male similar to female...............................................................11

 

11a.    Antennal insertion definitely more than one torulus diameter above free margin of clypeus; if doubtful, then

     either eyes diverge ventrally or side of head ("cheeks") carinate..........................................................13

 

11b.    Antennal insertion less than one torulus diameter above free margin of clypeus; if doubtful, side of head

without carinae..............................................................................................................................................12

 

12a.    Antennae arise at side and below free margin of clypeus; abdominal petiole longer than wide (common in

North American collections)............................................................................Pteromalidae  (Spalangiinae)

 

12b.    Antennae arise slightly above free margin of clypeus; abdominal petiole not visible (rare in North American

collections)........................................................Pteromalidae  (Ceinae)  [also see Asaphinae & Eunotinae].

 

13a.    Fore wing stigma enlarged, longer than stigmal vein, and projects toward hind margin of wing; ovipositor

sheaths always exserted; antennae with 7 funicle segments ............................Torymidae (Megastigminae).

 

13b.    Fore wing stigma not enlarged, shorter than stigmal vein (stigma at times surrounded by pigmented stainlike

area); ovipositor and antenna variable......................................14

 

14a.    Scutellum with submedian grooves that meet prescutal sutures and delimit median rectangular area (ra) or

stigmal vein long and almost at right angle to marginal vein (rare in collections from fig fruits in

Florida) ..............................................................................................................Torymidae  (Sycophaginae)

 

14b.    Scutellum without submedian grooves, prescutal sutures separated from scutellum by axilla (ax); either

stigmal vein ling and angled off of marginal vein or short (common & widespread in North America) ..............15

 

15a.    Hind coxa much longer and winder than forecoxa by 2-3 times; if doubtful, then prescutal sutures absent or

weak and female with exserted ovipositor...................................................................................................16

 

15b.    Hind coxa nearly same size as fore coxa; if doubtful, then prescutal sutures well developed and female

ovipositor not exserted................................................................................................................................18

 

16a.    Ovipositor definitely exserted; both sexes: abdomen without pits; propodeum postero-laterally angled and

does not project over hind coxa (dorsal view); cerci of last tergum elongated and with long setae (not as

apparent in male as female); prepectus subequal to tegula; hind tibial spurs thin....... Torymidae...(Subfamilies:   17)

 

16b.    Ovipositor not exserted; both sexes:  abdomen with pits; propodeum postero-laterally rounded and projects

over hind coxa (dorsal view); cerci of last tergum like a disk; prepectus much smaller than tegula; hind

tibial spurs thickened....................................................................................................................Ormyridae

 

17a.    Metapleuron with straight anterior margin.................................................Torymidae  (Monodontomerinae)

 

17b.    Metapleuron with anterior margin angulate or protruding forward .........................Torymidae  (Toryminae)

 

18a.    Pronotum rectangular in dorsal view, about as wide as scutum, sides parallel and flat laterally; body black,

yellow, or mixed black & yellow, but rarely faintly metallic; abdomen usually oval in crossview and

compressed laterally................................................................................. Eurytomidae..(Subfamilies:   19)

 

18b.    Pronotum in dorsal view narrowed to a transverse strip, or not visible (if elongated, then narrower at base

than apex and sides concave to accomodate front femora (rare, some Cleonyminae); body often metallic blue or

green, rarely black; abdomen usually keel-shaped (triangular in cross view) and somewhat compressed dorsally

........... 1

 

19a.    Prepectus (p) as large or larger than tegula.......................................................Eurytomidae  (Eurytominae)

 

19b.    Prepectus smaller than tegula.........................................................................................................................20

 

20a.    Scutellum with projection; tegula sculptured......................................................Eurytomidae  (Heimbrinae)

 

20b.    Scutellum without projection; tegula smooth..........................................................Eurytomidae  (Rileyinae)

 

21a.    Pronotum not visible in dorsal view, covered by distinctly arched scutum; abdomen like a rudder, on long

petiole.......................................................................................................Eucharitidae...(Subfamilies:   22)

 

21b.    Pronotum visible in dorsal view, scutum not heavily arched; abdomen usually elongated and petiole usually

not visible (petiolate forms occur)..............................................................................................................23

 

22a.    Prepectus fused to pronotum..............................................................................Eucharitidae  (Eucharitinae)

 

22b.    Prepectus not fused to pronotum.........................................................................Eucharitidae  (Oraseminae)

 

23a.    Abdomen covered by first two terga (or seemingly covered by single tergum); body short and squat; head

with well defined clypeus and at least 1 mandible with 2 teeth ................Perilampidae  (Subfamilies:   24)

 

23b.    Abdomen with 3 or more readily visible terga; body usually elongated; head variable but usually with

inconspicuous clypeus and small mandibles with 3-4 teeth.......................Pteromalidae...(Subfamilies:   25)

 

24a.    Prepectus not fused to pronotum; suture clearly visible............................ ..Perilampidae  (Chrysolampinae)

 

24b.    Prepectus fused to pronotum (suture absent or faint).........................................Perilampidae  (Perilampinae)

 

25a.    Axillae (ax) advanced far forward of scutellum or cuts a distinct angle into side lobe of scutum...................26

 

25b.    Axillae not extended forward of scutellum, or if slightly advanced, does not cut a distinct angle into side lobe

of scutum.......................................................................................................................................................28

 

26a.    Axillae enlarged, nearly meeting medially; body covered with white, scale-like setae ................Pteromalidae

 (Eutrichosomatinae)

 

26b.    Axillae not enlarged, not close medially; body without white, scale-like seta ....................................27

 

27a.    Scutellum posterior without triangular "projection" and with parallel dorsal grooves ........... Pteromalidae 

(Colotrechninae)

 

27b.    Scutellum posterior with triangular "projection" (is part of metanotum) and without apparent dorsal

grooves........................................................................................................Pteromalidae  (Macromesinae)

 

28a.    Head in dorsal view with posterior ocelli touching sharp occipital edge ..............Pteromalidae  (Eunotinae)

 

28b.    Head in dorsal view with posterior ocelli distant from rounded occipital margin; if doubtful, then head with

curved black spines ........................ 9

 

29a.    Head with projection between antennae, visible both from above and side (antennae not shown) ............

Pteromalidae  (Cerocephalinae)

 

29b.    Head without interantennal projection ................... 30

 

30a.    Head and thorax dorsally with black, curved spines; hind coxae with find transverse carinae .........................

.............................................................................................................................Pteromalidae  (Diparinae)

 

30b.    Head and thorax may have setae, but not black spines; hind coxae sculptured or smooth, without transverse

carinae..........................................................................................................................................................31

 

31a.    Body typically elongated (1-2 cm.); head with ridged, raised areas between eye and scrobal basin.  (Very rare

in North America).........................................................................................Pteromalidae  (Leptofoeninae)

 

31b.    Body less elongated (usually less than 1 cm.); head without ridged, raised area between eye and scrobal basin

(commonly collected in North America) ........... 32

 

32a.    Eyes divergent ventrally, parallel dorsally; pronotum often, though not always, longer than wide ...................

................. Pteromalidae  (Cleonyminae)

 

32b.    Eye margins mostly parallel; pronotum always wider than long ..................................... 33

 

33a.    Either eyes, head, and thorax densely covered with setae, or scutellum largely polished and with only 2 pairs

of bristles (rare in North American collections) .................................... 34

 

33b.    Eyes not densely covered with setae, head and thorax occasionally so; scutellum rarely with paired bristles,

but if so there are 3 or more pairs and they are inconspicuous .......................................35

 

34a.    Eyes, head and thorax densely covered with setae........................... Pteromalidae  (Herbertinae)

 

34b.    Eyes not covered with setae; scutellum largely polished and with 2 pairs of prominent bristles ......................

....... Tetracampidae

 

35a.    Sides of head ("cheeks") laterally carinate ..................Pteromalidae  (Asaphinae)

 

  35b.    Sides of head rounded laterally ........... Pteromalidae (Pteromalinae / Miscogasterinae)

 

36a.    Cercus at apex of gaster; fore and midcoxae separated (midcoxa posterior to midpoint of mesopleuron);

axillae (ax) do not meet medially (if so, at least as long as wide); marginal vein longer than stigmal or

postmarginal .........................37

 

36b.    Cercus anterior to apex of gaster; fore & mid coxae nearly touching (mid coxa anterior to middle of

mesopleuron); axillae (ax) meet medially; marginal vein usually shorter than stigmal or postmarginal

................ Encyrtidae

 

37a.    Prescutal sutures rarely visible, do not meet; prepectus flat, not projected .....Eupelmidae...(Subfamilies:   38)

 

37b.    Prescutal sutures meet medially; prepectus inflated and projected forward ..........................Tanaostigmatidae

 

38a.    Lack membranous area anterior to mid coxal insertion................................... Eupelmidae  (Metapelmatinae)

 

38b.    With membranous area (m) anterior to midcoxal insertion............. 39

 

39a.    Scutum wider than pronotum, with anterolateral shoulders produced ....................Eupelmidae  (Calosotinae)

 

39b.    Scutum not much wider than pronotum, with anterolateral shoulders indistinct ....Eupelmidae  (Eupelminae)

 

40a.    Usually 1 mm. or longer; body often metallic or dark in color; abdomen narrowly joined at propodeum

(petiole may or may not be apparent); tarsi always with 4 segments; postmarginal vein present or

absent ................... 41

 

40b.    Usually 1 mm or less in length; body mostly pale yellow to white, sometimes with dark markings or wholly

dark, but not metallic; abdomen broadly joined to propodeum; postmarginal vein absent; tarsi usually with

3-5 segments (if 4 segments, then club large and undivided or wing fringed with long setae, or middle tarsi

with only 4 segments) ...... 45

 

41a.    Hind coxa greatly enlarged; posterior scutellum with triangular, usually translucent flap overhanging

propodeum; hind tibia with irregular, linear, or diamond-shaped patterns of setae; habitus as shown . .......  Elasmidae

 

41b.    Hind coxa not greatly enlarged (normal); posterior scutellum without overhanging triangular flap; hind tibia

without irregular setal patterns............................ Eulophidae..(Subfamilies:   42)

 

42a.    Scutellum with 1 pair of setae; submarginal vein with 2 setae; face usually with scrobal and facial grooves

............. Eulophidae  (Entedoninae)

 

42b.    Scutellum with 2 pairs of setae (rarely 3 or more); submarginal with 3 or more setae (rarely with 1 or 2); face

usually without distinct grooves...................................................................................................................43

 

43a.    Fore wing with bare area posterior to marginal vein with single row of setae; usually with 2-3  "lines of setae"

radiating from stigmal vein.................. Eulophidae  (Euderinae)

 

43b.    Fore wing usually evenly setose posterior to marginal vein without row of setae; rarely with any "lines of

setae" radiating from stigmal, when present, usually only............ 44

 

44a.    Postmarginal vein usually absent; scutellum often with paired submedian grooves that divide the scutellum

into 3 distinct pieces.................. Eulophidae  (Tetrastichinae)

 

44b.    Postmarginal vein present; scutellum without submedian grooves, rarely with lateral grooves, when present at

extreme lateral margins..................... Eulophidae  (Eulophinae)

 

45a.    Tarsi with 3 segments; setae on wings usually arranged in rows; stigmal vein usually elongated; antennae

short and with few discernible funiculars, male with elongated antennal "setae."................. Trichogrammatidae

 

45b.    Tarsi with 4-5 segments; setae on wings largely absent, evenly covering wings, orwith only a few bare spots

or rows present; stigmal vein short and not obviously divergent from wing margin; antennae variable, but

usually with discernible funicles (if not, then with large undivided club).......................... 46

 

46a.    Propodeum without median triangular area; scutellum (sc) not transverse (anterior, posterior sides not

parallel), axillae (ax) distinct from scutellum, rarely meeting medially; club of antenna almost always

segmented (a few species here have antennae like Signiphordae).  Axillae (ax) do not meet medially,

generally widely separated; prescutal sutures (n) present; (antennal club in Eretmocerus large and

undivided, tarsi with 4 segments)........................................ Aphelinidae

 

46b.    Propodeum with triangular median area (ma); scutellum (sc) transverse (sides parallel), axillae either united

with scutellum or widely separated; club of antenna elongated and not segmented ..............Signiphoridae

 

REFERENCES:

 

Grissell, E. E. & M. E. Schauff.  1990.  A Handbook of the Families of Nearctic Chalcidoidea (Hymenoptera).

     Publ. Ent. Soc. Wash..  Cushing-Malloy, Ann Arbor, MI.  85 p.