Identification of Muscidifurax spp. parasitoids of muscoid flies, by composition patterns of cuticular hydrocarbons

Gas chromatographic analysis of cuticular hydrocarbons of Muscidifurax spp. adult females revealed species-specific patterns of composition that allowed identification of Muscidifurax raptor Girault and Sanders, Muscidifurax zaraptor Kogan and Legner, and Muscidifurax raptorellus Kogan and Legner. A total of 18 components, all C29-C37 alkanes and methylalkanes, accounted for over 90% of the total cuticular hydrocarbons for all three species. Muscidifurax zaraptor was characterized by a high ratio (11.9) of 3-MeC31:internal Me2C35'S, whereas this ratio was <3 for the other species. Muscidifurax raptorellus was characterized by a low (<1) 3-MeC31:3,7,15-Me3C37 ratio compared with ratios of 3.1 and 6.3 for these components in M. raptor and M. zaraptor, respectively. Three populations of M. raptorellus could be distinguished from one another based on two other component ratios (5- and 7-MeC31:3MeC32, 5- and 7-MeC31:3,7- to 3,15-Me2C33) With either 100% (Nebraska population) or 90% (Chilean and Peruvian populations) certainty. Comparison of M. raptor colonies established from five different locations (Florida, France, Germany, Brazil, Hungary) indicated that the hydrocarbon pattern was highly conserved in this species. A dichotomous key to species based on ratios of cuticular hydrocarbon components unambiguously classified the 50 samples of Muscidifurax spp. used to construct the key, plus five additional samples from different geographic locations. (C) 1998 Academic Press.