Description & Statistics

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).

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.

This worldwide family has more than. 3,002 known species as of 2000. Diagnostic characters include an antenna with a short arista; vein M-1+2 not sharply deflected towards R-4+5, cell R-5 is not conspicuously narrowed apically; body bristly on thoracic dorsum. The body is rather small, resembling a blowfly. The hypopleura are without bristles.

This is a large and diverse family of Muscoidea flies. Name came from Greek "anthos" (flower) + "myia" (a fly). Some species are commonly called "root-maggots", as the larvae are found in the stems and roots of various plants. As larvae, some also feed on decaying plant material, and some are leaf miners; the family also includes inquilines, commensals, and parasitic larvae.

Some species in the family are significant agricultural pests, particularly some from the genus Delia, which includes the onion fly (Delia antiqua), the wheat bulb fly (Delia coarctata), the turnip root fly (Delia floralis), the bean seed fly (Delia platura) and the cabbage root fly (Delia radicum).

References: Please refer to <biology.ref.htm>, [Additional references may be found at: MELVYL Library ]

Cole, F. R. 1969. The Flies of Western North America. Univ. Calif. Press, Berkeley & Los Angeles. 693 p.

Clausen, C. P. 1940/1962. Entomophagous Insects. McGraw-Hill Book Co., Inc., NY. & London. 688 p. [reprinted 1962 by Hafner Publ. Co.].

Hobby, B. M. 1934. Ent. Mon. Mag. 70: 185-90.

Seguy, E. 1937. Genera insectorum, Fasc. 205, Bruxelles.

Stein, P. 1920. Beitr. Arch. Naturges. 84: 1-106.

Thomson, R. C. 1937. Parasit. 29: 273-358.