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[For educational purposes only; do not review, quote or abstract]

CHLOROPID GNATS (Hippelates spp., Leptoconops spp., etc.) -- Diptera, Chloropidae

These are expophilic synanthropic species which include flies that persist in nature in the absence of humans, but whose populations can increase dramatically as a result of certain human activities such as providing more breeding habitat. The complex of problems that confront field programs in biological control of exophilic flies has clearly had a dampening effect on research in this area. The unforseen problems associated with attempts to biologically control the eye gnat, Hippelates collusor (Townsend), in California exemplify those problems. In the early 1960s, a concerted effort was mounted to control this gnat with the use of both indigenous and exotic parasitoids in orchards in southern California. About a dozen species and strains were evaluated for several years. Some of the exotics established, but eye gnat reductions were obvious only where cultivation practices were curtailed (Legner et al. 1966, Legner 1970). Cultivation of the orchards buried the larvae and pupae of the eye gnat below the search zone of the parasitoids and cultivation also removed vegetation that offered the parasitoids protection and possibly nutrients (Legner 1968, Legner & Olton 1969, Legner & Bay 1970). Buried eye gnats emerged from several centimeters below the soil surface and thus continued to pose a serious problem (Bay et al. 1976).

Biting gnats of the genus Leptoconops have bee investigated for biological control, with extensive surveys conducted for natural enemy predation. Although no natural enemies were ever imported to combat this group of gnats, natural predation is effective in maintaining population densities below annoyance thresholds if the breeding habitat is managed properly (Legner et al. 1970).

Please refer to additional references cited below for greater detail on host and natural enemy biologies and biologcial control activities. [ Please refer also to Selected Reviews & Detailed Research #1, #2 ]

REFERENCES: [ Additional references may be found at: MELVYL Library ]

Bay, E. C. & E. F. Legner. 1963a. The prospect for the biological control of Hippelates collusor (Townsend) in southern California. Proc. Calif. Mosq. Contr. Assoc., Inc. 31: 76-79.

Bay, E. C. & E. F. Legner. 1963b. Quality control in the production of Hippelates collusor (Tsnd.) for use in the search and rearing of their natural enemies. Proc. New Jersey Mosquito Exterm. Comm. 1963. 403-410.

Bay, E. C., E. F. Legner & R. Medved. 1964. Hippelates collusor (Diptera: Chloropidae) as a host for four species of parasitic Hymenoptera in southern California. Ann. Entomol. Soc. Amer. 57(5): 582-584.

Legner, E. F. 1966. Competition among larvae of Hippelates collusor (Diptera: Chloropidae) as a natural control factor. J. Econ. Entomol. 59(6): 1315-1321.

Legner, E. F. 1967. Two exotic strains of Spalangia drosophilae merit consideration in biological control of Hippelates collusor (Diptera: Chloropidae). Ann. Entomol. Soc. Amer. 60(2): 458-462.

Legner, E. F. 1968. Parasite activity related to ovipositional responses in Hippelates collusor. J. Econ. Entomol. 61(5): 1160-1163.

Legner, E. F. 1969. Distribution pattern of hosts and parasitization by Spalangia drosophilae (Hymenoptera: Pteromalidae). Canad. Entomol. 101(5): 551-557.

Legner, E. F. 1970a. Advances in the ecology of Hippelates eye gnats in California indicate means for effective integrated control. Proc. Calif. Mosq. Contr. Assoc., Inc. 38: 89-90.

Legner, E. F. 1970b. Attraction of Hippelates eye gnats and other minute Diptera to baits and man with considerations on competitive displacement by exotic non-problem species. Proc. Calif. Mosq. Contr. Assoc., Inc. 37: 119-126.

Legner, E. F. 1971. Observations on the distribution, relative abundance, and behavior of anthropophilic Chloropidae in the Caribbean area. Carib. J. Sci. 11(3-4): 163-169.

261. Legner, E. F. 1995. Biological control of Diptera of medical and veterinary importance. J. Vector Ecology 20(1): 59-120.

Legner, E. F. & E. C. Bay. 1964a. Natural exposure of Hippelates eye gnats to field parasitization and the discovery of one pupal and two larval parasites. Ann. Entomol. Soc. Amer. 57(6): 767-769.

Legner, E. F. & E. C. Bay. 1964b. La primera exploración para buscar enemigos naturales de Hippelates en Puerto Rico (Insecta: Chloropidae). Carib. J. Sci. 4(4): 467-471.

Legner, E. F. & E. C. Bay. 1965a. Predatory and parasitic agents attacking the Hippelates pusio complex in Puerto Rico. J. Agric. Univ. Puerto Rico 49(3): 377-385.

Legner, E. F. & E. C. Bay. 1965b. Ooencyrtus submetallicus Howard in an extraordinary host-relationship with Hippelates pusio Loew. Canad. Entomol. 97(5): 556-557.

Legner, E. F. & E. C. Bay. 1965c. Culture of Hippelates pusio (Diptera: Chloropidae) in the West Indies for natural enemy exploration and some notes on behavior and distribution. Ann. Entomol. Soc. Amer. 58(4): 436-440.

Legner, E. F. & E. C. Bay. 1970a. The introduction of natural enemies in California for the biological control of noxious flies and gnats. Proc. Calif. Mosq. Contr. Assoc., Inc. 37: 126-129.

Legner, E. F. & E. C. Bay. 1970b. Dynamics of Hippelates eye gnat breeding in the Southwest. Calif. Agric. 24(5): 1, 4-6.

Legner, E. F. & G. S. Olton. 1969. Migrations of Hippelates collusor larvae from moisture and trophic stimuli and their encounter by Trybliographa parasites. Ann. Entomol. Soc. Amer. 62(1): 136-141.

Legner, E. F., E. C. Bay & T. H. Farr. 1966a. Parasitic and predacious agents affecting the Hippelates pusio complex in Jamaica and Trinidad. Canad. Entomol. 98(1): 28-33.

Legner, E. F., G. S. Olton & F. M. Eskafi. 1966b. Influence of physical factors on the developmental stages of Hippelates collusor in relation to the activities of its natural parasites. Ann. Entomol. Soc. Amer. 59(4): 851-861.

Legner, E. F., E. C. Bay & R. A. Medved. 1966c. Behavior of three native pupal parasites of Hippelates collusor in controlled systems. Ann. Entomol. Soc. Amer. 59(5): 977-984.

Legner, E. F., R. D. Sjogren & J. T. Wiles. 1970. Effects of low biuret urea on natural populations of Hippelates collusor (Townsend) and Leptoconops kerteszi (Kieffer). J. Amer. Mosq. Contr. Assoc. 30(4): 634-640.

Legner, E. F., L. Moore & R. A. Medved. 1971. Observations on predation of Hippelates collusor and distribution in southern California of associated fauna. J. Econ. Entomol. 64(2): 461-468.