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DIPTERA, Sarcophagidae
(Brauer 1889) Description & Statistics
Sarcophagidae
is a moderately sized family with ca. 1,030 species known by 1993. Although widespread globally, they are
most diverse in the tropics.
Important morphological characters include an antennal arista that is usually
plumose on the basal half, occasionally bare; bristles on posterior abdominal
segments conspicuous. The body is
medium-sized, but several species are 14-16 mm. long; abdominal surface is
pollinose (powdery), reflects light in a checkered or mottled pattern. They are strong fliers. Early
reviews of host preferences were by Aldrich (1915) and Greene (1925a). Entomophagous species are in subfamilies
Sarcophaginae and Melanophorinae.
Many species of Sarcophagidae are limited to carrion, others to manure;
but there are both predaceous and parasitic species. Predaceous species attack egg pods of
Acrididae. Well known genera having
this habit are Sarcophaga
and Blaesoxipha. Oophagomyia
and Wohlfahrtia are
predaceous in the egg capsules of the same host group, and an occasional
species of Blaesoxipha is
both parasitic on the active stages and predaceous on the eggs. Mantidophaga
is an internal parasitoid of the late nymphs and adults of Mantidae. Clausen
(1940) noted that an unusual degree of plasticity was revealed in the
behavior of species of this family, and many were apparently only in the
transitional stages to obligate parasitism.
Most parasitic species are primary, solitary, endoparasitoids, though
gregarious species are known. The
principal host range includes Orthoptera (Acrididae, Mantispidae) and
Lepidoptera, but other insect orders may be attacked. A few species are parasites of snails,
while others are carrion feeders or vertebrate parasites. A
host group frequently attacked by species of the Sarcophaginae are the social
wasps and bees. The relationship ins
some cases is strictly parasitic, while in others it is commensal. Myiapis
and Senotainia are internal
parasitoids of worker honeybees, and Sphixapate
develops within the larvae. Metopia and Brachicoma are external
parasitoids or predators of the brood of wild bees, the latter genus
attacking mainly bumblebees. Hilarella and Miltogramma develop on various insects
which are stored in cells of hunting wasps or on the material with which the
cell of bees are provisioned. Several
genera have widely different host preferences. Lepidopterous larvae and pupae frequently yield sarcophagid
flies, and it has been thought that there were parasitic. Several species of Sarcophaga associated with the gypsy moth were found to be
scavengers only (Patterson 1911).
Young larvae were unable to enter healthy larvae or pupae, and if
artificially introduced into the bodies of living individuals they died. However, species of Agria are predaceous on pupae of Lepidoptera. Eleodiomyia
has been reared from adult beetles of the family Tenebrionidae; Scarabaeophaga from pupae and
adults of Cotinus nitida L.; and Sarcophaga spp. from adult
Pentatomidae, Blattidae, etc (Clausen 1940/62). Arachnidomyia
sp. has been reared from egg sacs of spiders and various genera and species
from snails. There
is a wide range in host preference found among the parasitic and predaceous
species of Sarcophaga. Not much is known regarding insect hosts
of Melanophorinae, although species have been reared occasionally from spider
egg masses and from coleopterous larvae and adults. Melanophora, Cirillia, and closely related
forms are parasitic in Isopoda (Porcellio,
Metaponorthus, Oniscus), and some species of
this subfamily have been reared from snails.
Biology &
Behavior
In
B. lineata, S.
lellyi and S. caridei, the maggots enter the host body through the thin
membrane at the base of the wing. B. filipjevi enters through the membranes of the abdomen or
through the genital opening. The
latter behavior is similar to that of Eleodiomyia
in attacking tenebrionid beetles.
Wood (1933) noticed that the maggots of S. destructor
readily enter freshly molted hosts but are not able to if the integument is
fully hardened. The host dies within
a short time after the larvae have entered the body. Mature larvae of B. linerata
and S. caridei emerge from the host while the latter is still
alive, and some parasitized individuals may recover. However, the hosts of Wohlfahrtia are usually dead before the larvae finish
feeding. They usually emerge through
the thin membranes of the neck, although some individuals of S. kellyi are believed to emerge through the anal opening. Wood (1933)
found that 78 % of attacked hosts of B.
lineata recovered, but only
38% were able to reproduce thereafter.
Relatively little growth occurs in S.
destructor as long as the
host remains alive. The young larvae
of this species attack the wing muscles, nd death results primarily through
infection. After this, development of
the parasitoid is rapid. Only 16% of
hosts containing one parasitoid larva died, while 92% died when two or more
were present. If hosts are immature
at the time of attack, they do not attain the adult stage. Larval feeding is confined mostly to the
fat body. The number of individuals
developing in each host varies, being usually only 2 in the case of B. lineata, a maximum of 11 in B. filipjevi
and 9 in S. caridei. There
is often a high percent parasitization by Sarcophagidae, but opinions vary as
to their value in natural control.
Smith (1915) stated that swarms of Dissosteira
longipennis Thoms. in New
Mexico were almost eliminated by S.
kellyi. Kunckel d'Herculais (1894) found
parasitization of Schistocerca
by sarcophagids in Algeria to be 69% in 1889 and 75% in 1890. The flies followed host swarms, harassing
them continuously. In the case of Wohlfahrtia euvittata in South Africa,
50-90% of Locustana were
found parasitized, and in some areas this attack was responsible for
discontinuing poisoning programs. Some
species that were discussed as internal parasitoids of nymphs and adults of
locusts are also predaceous in egg masses of the same hosts. This range in habit has been found for Sarcophaga opifera Coq. in British Columbia, and Treherne &
Buckell (Clausen 1940/62) thought that the larvae, after leaving the body of
the adult host, continued their development on the eggs in soil. Potgieter (1929) in South Africa observed
that W. euvittata is very important in natural control of Locusta pardalina Wlk., when parasitic on the active stages. About 50% of the egg masses in one area
were destroyed by this fly. The
maggots are laid in groups in the openings of partly hatched egg pods or in
the froth at the upper ends of those freshly laid or exposed. Larvae in various stages of development
were found on the surface of the ground, and these were migrating to other
egg pods for further feeding (Potgieter 1929). Sarcophagids
that are parasitic or predaceous on the brood of bees and wasps are mostly in
genera Metopia, Brachicoma and Hilarella. Bougy (1935) described the attack of H. stictica Meig on Ammophila
hirsuta Scop. in
France. The host stores its nest with
noctuid larvae, and the female fly appears while the prey is being
transported to the nest. She does not
attempt to larviposit on it at this time.
It is only after the caterpillar has been placed in the cell and the Ammophila egg laid that she
evades the host, enters the burrow and lays her own minute larva alongside
the host egg. This egg is consumed
within 24 hrs., and the larva then enters the body of the caterpillar to
complete its development. Each
individual may be regarded as a predator on the egg of Ammophila and an internal parasitoid of noctuid
caterpillars. Mature
larvae and young pupae of bumblebees are parasitized by B. sarcophagina
Tns. in North America. The live young
are laid on or in the brood cells.
They enter the body and feed until larval maturity. Pupation occurs in the nest material at
the bottom of the comb. B. davidsoni Coq. is thought to lay eggs directly on the
larvae; and after one is consumed, the parasitoid larva enters other cells to
attack their occupants. Metopia leucocephala Rossi has been found in cells of Philanthus. Females enter the host burrow for a short
distance and there lay their larvae, which have to find their own way to the
cells, sometimes several feet away.
Adult honeybees are found heavily parasitized by Senotainia tricuspis
Meig. in some parts of Russia. The
larvae feed principally in the thoracic region, the same habit being recorded
for Myiapis angellozi Seguy (Seguy 1930). Agria mamillata Pand. is predaceous
on pupae of Hyponomenta in
Italy, with flies appearing in the field in early June to lay their partially
incubated eggs on caterpillars when they are mature but before cocoon
formation. The young larva enters the
body of the pupa and quickly consumes its contents. It then penetrates the adjoining cocoons and continues its
feeding, destroying 50 or more pupae per single larva before maturity
(Servadei 1931). S. latisterna Perk was reared from
various pupae of Lepidoptera, where it was believed to be a true facultative
parasite (Hallock 1929). Thompson
(1920a, 1934) studied several sarcophagids that are parasitic in isopods of
genera Oniscus, Porcellio and Metaponorthus. They differ in several ways from the
general habits of the family. The
adaptive characters of the 1st instar larvae, as well as the habits of the
immature stages, show a closer biological affinity with Tachinidae than by
any other members of Sarcophagidae. Parafeburia maculata Fall, is a solitary
internal parasitoid of the first two genera.
Its unincubated eggs are probably laid in the general vicinity of the
hosts or where they are in the habit of congregating. They hatch in ca. one week when these membranous
eggs give rise to planidium type larvae.
This is the only instance in the Muscoidea in which this larval form
hatches from membranous eggs that are unincubated at the time of laying. Young larvae enter the host body through
the soft cuticle separating the ventral sclerites or at the bases of the
appendages. Once inside the host, the
larva is found with its posterior end fixed in a perforation in the
integument, and a respiratory funnel is formed. The 2nd instar larva has a very thin integument, and tests have
shown that an exchange of gases takes place through it; The greater part of the oxygen
requirements of the larva may be secured in this way, and pupation occurs
within the remains of the host. Clausen
(1940) commented on the definite effect on the reproductive system and the
secondary sexual characters of the host as a result of parasitism by Parafeburia. Female ovaries are atrophied, owing to
absorption of fat by the parasitoid, and such females do not develop a brood
pouch. Less complete information
regarding Cirillia angustifrons Rond. was
presented by Thompson (1920a).
General habits are similar to those for Parafeburia, with the outstanding distinction in the host
relationships being the formation of the integumentary respiratory funnel by
the larvae. This habit is unknown elsewhere
in Sarcophagidae, although it is common in Tachinidae, indicating a higher
development of the parasitic relationship than has been attained by other
species. Life Cycle
The
life cycle of parasitic Sarcophagidae, from larviposition to adult emergence,
is relatively short, being completed in 16-30 days, of which the larval
feeding period takes only 5-10 days.
In Wohlfahrtia,
larval maturity is followed by a resting period of 6-12 days, and the pupal
stage then requires 16-30 days.
Several generations are usually produced each year, and 5-6 are
recorded for S. kellyi. Hibernation is known for B. lineata and S.
kellyi, in both of which
mature larvae rather than pupae persist through winter. The life cycle of P. maculata
in Oniscus and Porcellio differs from the
general habit of the family by having only a single generation each
year. Adults appear in midsummer, and
winter is passed as 2nd instar larvae within the live host (Clausen 1940/62). For
detailed descriptions of immature stages of Sarcophagidae, please see Clausen
(1940/62). References: Please refer to <biology.ref.htm>, [ Additional references
may be found at: MELVYL Library] Aldrich, J. M. 1916.
Vol. 1, Thomas Say Found., Ent. Soc. Amer. 302 p. Allen, H. W. 1926.
Proc. U. S. Natl. Mus. 68:
1-106. Clausen, C. P. 1940/1962. Entomophagous Insects.
McGraw-Hill Book Co., Inc., NY. & London. 688 p.
[reprinted 1962 by Hafner Publ. Co.]. Cole, F. R. 1969.
The Flies of Western North America.
Univ. Calif. Press, Berkeley & Los Angeles. 693 p. James, M. T. & R. F.
Harwood. 1969. Herm's Medical Entomology, 6th ed. MacMillan Co. 484 p. Kunckel D'Herculais, J. 1894.
Les Dipteres parasites des Acridiens: les Muscidae vivipares a larves
Sarcophages. Aptenie et castration
parasitaire. Acad. Sci. Compt. Rend.,
Paris 118: 1106- Potgieter, J. T. 1929.
A contribution to the biology of the brown swarm locust Locustana pardalina (Wlk.) and its natural enemies. Proc. Agr., Union So. Afr., Dept. Agr.
& For., Pan-Afr. Agr. Vet. Conf., Pretoria. p. 265-308. Roback, S. S. 1954.
Illinois Biol. Mon. 23: 1-181. Wood, O. H. 1933.
Notes on some dipterous parasites of Schistocerca and Locusta
in the Sudan. Bull. Ent. Res.
24: 521-30. |