Symposium: Insect Behavioral Ecology-'88: Genetic Considerations in the Study of Attack Behavior of Parasitoids, with Reference to Muscidifurax Raptor (Hymenoptera: Pteromalidae)

Abstract

Genetic variation in attack behaviors of parasitoids is taxonomically widespread, and evidence for genetic variation comes from two sources: from comparisons among strains and from selection experiments. Most workers on genetics of attack in parasitoids treat attack behaviors as traits with relatively simple inheritance. Attack behaviors are complex traits that have polygenic inheritance that can be complicated by linkage and genetic correlation with other traits, and by genotype-environment interaction. Ignoring the genetic complexity of attack behavior may limit the effectiveness of searching for new strains of parasites and may confound selection for favorable traits. I demonstrate this point through a literature review, and through my research on the genetics of Muscidifurax raptor Girault & Sanders, a pteromalid that attacks the pupae of flies that breed in animal filth. Attack rates, functional response, the numbers of eggs laid per patch, sex ratio, and development times vary among five geographis strains of M. raptor. Furthermore, brood size, sex ratio, and development time are positively correlated. This tangle can be unravelled by careful quantitative genetic experiments, where genetic correlation and genotype-environment interaction can be measured.