File: <antho1.ima.htm> [For educational purposes only] Terminology Glossary <Principal Natural
Enemy Groups > <Citations> |
Immature
Stages of Anthomyiidae
Most larval Anthomyiidae are plant feeders, and their habit of invading
roots gave them the name "root maggots." Some species feed on dung, others are entomophagous. Adult flies are mainly predaceous, most
frequently attacking other Diptera, often of the same family (Clausen
1940/62). Most entomophagous species
are predaceous, although some species are primary, internal, solitary or
gregarious parasitoids. A number of
predaceous species attack the egg pods of grasshoppers and locusts, while the
adults of other species are predaceous on other flies, often members of the
same family. A early review of the
food habits of adult anthomyiids by Hobby (1934) noted the genera Lispa, Coenosia, Trichophthicus,
Helina, Ophyra, Hylemya,
Pegomyia and Prosaepia has having
entomophagous species. Lispa spp. are predaceous on various
aquatic larvae. Few species have been
used in biological control, although those attacking locust eggs are
important natural controls. Larval
food habits are exceeding variable; some are plant feeders, others scavengers
on decaying vegetable matter, and a number are parasitic or predaceous on
immature stages, and occasionally adults, of other insects. The most valuable entomophagous species
for natural control of crop pests are in genera Hylemya and Paregle,
which develop as predators in egg capsules of locusts. Acridomyia
is parasitic in larger nymphs of Locusta
in Russia, and Muscina pabulorium Fall. is reported as
a natural enemy of Lymantria
monacha L. and Dendrolimus pini L. in Europe. Muscina
stabulans Fall. feeds on
caterpillars of the latter two species and on larvae of housefly. Thomson (1937) discussing the food habits
of a number of species noted that certain species of Myiospila, Mydaea
and Hebecnema are partially
dependent on living food for their development, which is provided by larvae
of other Diptera present in dung.
Larvae of aquatic or semiaquatic species feed consistently on larvae
of other Diptera. Phaonia miribilis confines its attack mostly to larvae and pupae
of mosquitoes, and P. variegata Meig., which is not
aquatic, requires solely mycetophilid larvae in fungi of the genus Polyporus. Semiaquatic species of Lispocephala and Lispa feed on Chironomus spp. and other
larvae (Williams 1938). Of those species
developing as predators in locust egg capsules, one of the more interesting
and important is Hylemya cilicrura Rond., the
"shellat fly" or "seed corn maggot," a serious crop
pest. Hylemya cilicrura
has occasionally been reared from locust eggs in North America, Riley (1878a)
noting that during one season it also destroyed 10% of the eggs of the Rocky
Mountain locust. Eberhardt (1930)
observed a maximum of 60 maggots in one egg capsule of the migratory locust
in Dagestan. In some areas nearly
100% were attacked. Blanchard (1933)
studied H. cilicrura attacking Schistocerca paranensis F. in
Argentina. The female was observed to
insert her ovipositor into the soil near the host egg capsule and to lay a
series of eggs at 5-second intervals, a maximum of 80 being deposited. Hatching required a minimum of 2
days. Larvae immediately entered the
capsule to feed. If the food
contained in one capsule was inadequate, they would move to another. Feeding was completed in 8-12 days, after
which they burrowed a short distance away in the soil and pupated. In summertime, the duration of the pupal
stage was 8-15 days. Eberhardt (1930)
found pupation to take place 4-6 cm. beneath the egg capsules. There were 3 generations annually, and
hibernation was principally in the pupal stage, although some adults and
larvae could be found in winter.
Gestation of females was exceptionally long, taking 30-60 days, and
adults lived more than 3 months. A gregarious internal parasitoid of 5th instar nymphs and adults
of Locusta migratoria L., Acridomyia sacharovi Stack females feed on the body fluids of the
host. The feeding puncture serves
also as a point of insertion for oviposition (Olsaufiev 1929, Rukavishnikov
1930). A maximum of 103 larvae were
found in a single host, although the average number completing development
was 20-30. Some hosts recovered from
attack by this parasitoid if the number of larvae was small. The spiracles, the anterior pair each with
11 papillae and the posterior pair with 9 openings, arranged in a 3/4 circle,
distinguish mature larvae. The first
brood of adults appeared in June, and there was at least 3 generations
annually. Winter was passed as pupae
in the soil. Phaonia mirabilis Ringd. shows a great
deal of adaptability to a predaceous life.
Larvae are aquatic in habit and feed on larvae and pupae of mosquitoes
(Tate 1935). The white eggs are 1.8
mm. long, ventrally keeled, and with lateral flanges. They are deposited on the water surface in
recesses of tree trunks, etc. The
larvae that emerge from these eggs have all the characters of typical 3rd
instar cyclorrhaphous larvae, which was verified by an examination of larvae
still within the egg. Thus, the early
appearance of this form is not due to rapid molting after hatching. No molts occur during the active larval
stage, and there are three groups of long, slender hairs, presumably sensory,
on the ventral surface of the thoracic segments; and paired retractile
protuberances, surmounted by numerous curved hooks, are present ventrally on the
2nd to 8th abdominal segments. The
anterior spiracles are 4-5 lobed, and the posterior ones have three
openings. The tracheal system is
modified for aquatic life, the main lateral trunks being expanded into two
large reservoirs, one in the thorax and the anterior portion of the abdomen,
and the other in the mid abdominal region.
Near each posterior spiracle, a short stout trachea is given off
ending in a blind sac, and mouthparts are well developed (see Clausen, 1940,
for diagrams). Please
CLICK on picture
to view details: The precocious assumption of the 3rd instar characteristics by the
larva at the time of hatching is seemingly correlated with the predatory role
that is immediately assumed, for the larva must overcome an active host in
water (Clausen 1940/62). It swims
freely, either entirely submerged or with posterior spiracles protruding
through the surface film. When
encountering a mosquito larva of pupa, it quickly encircles it by the
anterior portion of the body, and firmly grasps it with the ventral
protuberances. More mosquitoes are
killed than consumed, so that each individual anthomyiid may account for more
than 100 during its lifetime (Clausen 1940/62). The egg stage lasts 3-4 days, and larval development requires
one month, and the pupal stage ca. 2 weeks.
Pupation occurs in crevices in decaying wood slightly above the water
surface. Thomson (1937) reported on the peculiar biology of Phaonia variegata Meig. in Scotland. Eggs are deposited on the upper surface of the pileus of fungi
of the genus Polyporus, and
the larvae are predaceous on those of Mycetophilidae in the fungus. Third instar larvae also were found to
hatch from the egg, and it was found that the scarcely recognizable exuviae
of a preceding instar are present.
Thomson believed that hatching of 3rd instar larvae from an egg could
be found commonly in the family. He
suggested that the occurrence of three active larval instars would prove to
be the exception in species of Mydaea
and Phaonia. The larva of P. variegata
differs from that of P. mirabilis by lacking the
conspicuous ventral pseudopods, surmounted with hooks, upon the abdomen,
which are replaced by bands of ventral spines at the anterior margins of the
first 8 abdominal segments. The anal
plate is found on the venter of the last abdominal segment. The larvae of several additional species of Phaonia were described by Keilin (1917), from decaying
wood, forest litter, etc. Larvae of P. leilini Coll, found in very moist decaying wood, are
similar to those of P. mirabilis, while larvae of P. cincta Zett., inhabiting wounds and rotting areas in
trees, have the same adaptive modifications as P. variegata. These studies deal particularly with
larval morphology, and include a discussion of a number of carnivorous
species in genera Allognota,
Melanochelia and Graphomyia. References: Please refer to <biology.ref.htm> [Additional
references may be found at: MELVYL Library] |