Drosophilidae (Diptera) collected in spring in Michigan

Drosophilids in mid-Michigan overwinter in a preadult stage. One hundred twenty-two individuals (84 male, 38 female) representing 14 species were collected over bait in April and May 1992. All appeared recently emerged and had entire wings. This agrees with earlier reports in Michigan and Massachusetts that Drosophila affinis group species overwinter as preadults. Among the species overwintering as preadults in Michigan, Drosophila affinis, D. algonquin, D. athabasca, D. robusta, D. falleni and D. recens have been found to overwinter as adults in New York. Latitude and climate may play a role in drosophilid overwintering stage.