No evidence for kin discrimination in cannibalistic tree-hole mosquitoes (Diptera : Culicidae)

Kin selection theory suggests that cannibalism is more likely to spread and be maintained if cannibalism of close relatives can be preferentially avoi ded. One important group of insects in which kin discrimination might be ex pected to evolve is cannibalistic tree-hole mosquitoes. Larvae of these spe cies develop in small, ephemeral water bodies, where they regularly encount er both relatives and nonrelatives. In this study we compared the degree of sib cannibalism with the degree of nonsib cannibalism in two ecologically distinct mosquito species: an anautogenous (blood-feeding) detritivore Tric hoprosopon digitatum (Culicinae) and an autogenous predator Toxorhynchites moctezuma (Toxorhynchitinae). Despite a wealth of literature documenting ki n-biased discrimination in other insects, neither of these tree-hold mosqui to species preferentially consumed nonrelatives. In the case of Tr. digitat um, the size-dependent nature of larval cannibalism may preclude additional selection for preferential consumption of nonrelatives, but in the autogen ous Tx. moctezuma the direct nutritive and indirect competitive benefits of indiscriminate cannibalism may outweigh the immediate costs of consuming a relative.