SEXUAL SELECTION, VIABILITY SELECTION, AND DEVELOPMENTAL STABILITY INTHE DOMESTIC FLY MUSCA-DOMESTICA

Associations between developmental stability, sexual selection, and vi ability selection were studied in the domestic fly Musca domestica (Di ptera, Muscidae). Developmental stability of the wings and tibia of fl ies of both sexes, measured in terms of their level of fluctuating asy mmetry, was positively associated with mating success in free ranging populations and in sexual selection experiments. Mated individuals may have obtained indirect fitness benefits from sexual selection of two different kinds, First, the entomopathogenic fungus Enthomophthora mus cae (Zygomycetes, Entomophthorales) infects and kills adult domestic f lies, and flies dead from fungus infections had more asymmetric wings than flies dead for other reasons. Experimental deposition of fungus s pores on uninfected dies demonstrated that flies with asymmetric wings were more susceptible to fungus infections than dies with symmetric w ings. Second, domestic dies were frequently eaten by insectivorous bar n swallows Hirundo rustica, and flies depredated by birds had more asy mmetric wings and tibia than surviving flies.