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Chloropids are usually phytophagous in habit, with several species being important crop pests. However, some species such as Siphonella palposa Fall, are predaceous, developing in the egg capsules of Stauroderus in Russia. Siphonella oscinina Fall. develops in egg sacs of spiders. Pseudogaurax signata L. (= Gaurax araneae Coq.) is a predator in the egg sacs of the black widow spider, Latrodectes mactans F. (Jenks 1936). The latter lays spindle shaped eggs on the outer surface of the spider's egg sac; and after hatching in 2-3 days, the young larvae burrow through the covering to feed on the eggs. After consuming the eggs over a period of ca. 2 days, they pupate in the same area.
This is a family of flies commonly known as frit flies or grass flies. There are approximately 2000 described species in over 160 genera distributed worldwide. These are usually very small flies, yellow or black and appearing shiny due to the virtual absence of any hairs. The majority of the larvae are phytophagous, mainly on grasses, and can be major pests of cereals. However, parasitic and predatory species are known. A few species are kleptoparasites. Some species in the genus Hippelates and Siphunculina (S. funicola being quite well known in Asia) are called eye gnats or eye flies for their habit of being attracted to eyes. They feed on lachrymal secretions and other body fluids of various animals including humans.
There are scant records of chloropids from amber deposits, mostly from the Eocene and Oligocene periods although some material may suggest that the group dates back to the Cretaceous or earlier.
Chloropisca glabra Meig. is a predator of the sugar beet root aphid, Pemphigus betae Doane, and has been considered to be the most effective natural enemy of this pest (Parker 1918). Hundreds of individuals are found on a single infested plant. The female crawls down the base of the plant to insert her ovipositor by a backward thrust into a soil crevice, where the eggs are laid. Aphids in the habitat provide the oviposition stimulus because no eggs are found on uninfested plants. Eggs hatch in 3-5 days, and each larva consumes up to 50 mature aphids during a 9-12 day development period. They remain as pupae for ca. 9 months, although some individuals emerge in 2-3 weeks, producing a partial 2nd generation. Anatrichus erinaceus Loew is predaceous on larger larvae of the rice borer, Schoenobius incertellus Wlk. in Taiwan (Clausen 1940/62).
Behavior varies among the wholly phytophagous, scavenger and predaceous species. Larvae of Pseudogaurax anchora Lw. and others of that genus feed on cast skins of Hemerocampa, while those of Botanobia darlingtoniae Jones feed on dead insects in pitcher plants. Other species in several genera have been found in the burrows of other insects where their roles were undetermined (Clausen 1940/62).
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Andersson, H., 1977 Taxonomic and phylogenetic studies on Chloropidae (Diptera) with species reference to Old World genear. Entom. Scand. Suppl. 8: 1-200 Keys most Old World genera.
Becker, T., 1910 Chloropidae. Eine monographische Studie. Archivum Zoologicum Budapest 1:23-174 Keys genera and species of world fauna.
Clausen, C. P. 1940/1962. Entomophagous Insects. McGraw-Hill Book Co., Inc., NY. & London. 688 p. [Reprinted 1962 by Hafner Publ. Co.].