Sex-specific response of a mosquito to parasites and crowding.

Host-parasite interactions are significantly influenced by the sex of the host and the environment in which the host is found. Sex-specific responses to parasite infection, however, may change according to the host environment. I examine the combined effect of parasite infection and crowding on males and females of the mosquito Aedes albopictus. At a high larval density, infected males experienced a greater relative reduction in body size than did infected females, whereas the pattern was reversed at low density. This experiment demonstrates the importance of the environment on sex-specific responses to parasites and contributes to a growing body of work examining sources of variation in host-parasite interactions.