Differential Predation by Fish on Two Species of Chaoborus (Diptera, Chaoboridae)

Abstract

Larvae of the 2 spp. C. obscuripes (V.D. Wulp) and C. flavicans (Meig.) differ with respect to shape and behavior. These characteristics are significant for a visually dependent predator. C. obscuripes, which has more pigment (e.g., larger eyes) and the least marked diel migration pattern, may be more susceptible to fish predation. The results from a field study, where C. obscuripes appeared after an experimental reduction of the fish population, were discussed. The importance of fish predation for the spatial distribution of C. obscuripes was examined.