Shed antlers as a larval environment: antler quality and adult performance of wild <i>Protopiophila litigata</i> (Diptera: Piophilidae)

Abstract The developmental environment can have an especially large impact on life history plasticity in animals, influencing body size, reproductive success, and longevity. This is because developmental processes interact with environmental factors to determine phenotypes such as body size, sexual investment, and metabolic rate, which in turn can influence longevity and senescence. We investigated how natural differences in the larval environment (discarded moose antlers) influenced development time, survival, and mating success of wild male antler flies, Protopiophila litigata Bonduriansky (Diptera: Piophilidae). Antlers become depleted of resources from year to year, as multiple generations of larvae feed within them. We collected larvae that grew inside nine different shed moose antlers, and we individually tracked them in the field as adults. Moose antlers that were more attractive to adult P. litigata also supported a greater number of larvae, suggesting they are of higher quality. Flies that developed in more attractive antlers completed metamorphosis more quickly but did not differ in body size, longevity, or lifetime mating success. This suggests that the observed differences in larval density may, in part, balance the variation in resource availability among antlers. Regardless of natal antler, large male P. litigata tended to live longer and have higher mating success, as found in previous studies of this species.