Parasites of the Face Fly and Two Other Species of Dung-Inhabiting Flies in Missouri1

Abstract

The parasitic insects attacking the face fly, Musca autumnalis De Geer, in Missouri were investigated during 1964 and 1965, along with those attacking Orthellia caesarion (Meigen) and Ravinia querula (Walker) in 1965. Since face fly populations are low most of the year in Missouri, a method of infesting field manure with face fly eggs from a laboratory colony, and subsequently recovering the puparia, was used. During 1964, 3 species of parasites, Aphaereta pallipes (Say), Eucoila impatiens (Say), and Aleochara bimaculata (Gravenhorst), were reared from the face fly. E. impaliens was the most frequent parasite recovered, Aphaereta pallipes was 2nd, and Aleochara bimaculata was 3rd. Parasitism was highest from mid-August through September. This feature is significant because parasitism during this period reduces the overwintering populations of adult face flies. In addition to the 3 species found attacking the face fly in 1964, 2 more were found in 1%5. However, both of these species, Alysia n. sp. and Muscidifurax raptor Girault and Sanders, were each reared from the face fly only once. Aphaerela pallipes was the most frequent parasite recovered, E. impatiens was 2nd, and Aleochara bimaculata was 3rd. As in 1964, parasitism was highest from mid-August through September. During 1965 O. caesarian was a major bucoprophilous host of A. bimaculala but not of Aphaereta pallipes and E. impatiens. R. querula was a major host of both A. pallipes and Aleochara bimaculata , but not of E. impatiens .