Breeding Sites of Snipe Flies (Rhagionidae) and Other Diptera in Woodland-Grass Soils

Abstract

During terrestrial surveys for immature and adult rhagionids in northern California (Mendocino Co.), USA, woodland-grass soils were found to be a breeding source for 8 species of snipe flies: Chrysopilus , 2; Ptiolina , 1; Rhagio , 1; and Symphoromyia , 4. Immatures of a Ptiolina sp. near zonata obtained by hand sorting moss-covered soil samples from 1978–1980 yielded 2 adults. This is apparently the first time that Ptiolina has been reported from the state and that Ptiolina immatures have been successfully reared in the Nearctic Region. Adults of 8 rhagionid species were collected in emergence traps from April to July and in December 1980, with emergence densities ranging from 0.04 individuals/m2 for S. inconspicua to 1.30/m2 for Ptiolina sp. Emergence traps also captured miscellaneous dipterans belonging to ca. 48 species in 20 families. Incidental to other studies, a single male of an undescribed species of Symphoromyia near truncata was taken in an emergence trap in Contra Costa Co.