Laboratory evidence for mate recognition behaviour in a member of the Culex pipiens Complex (Diptera : Culicidae)

Abstract

Assortative mating between the mosquito taxon Culex pipiens variety molestus and both Culex fatigans and C. globocoxitus is examined in laboratory choice experiments by use of alcohol dehydrogenase allozymes, detected by gel electrophoresis, as genetic markers. Complete positive assortative mating results when molestus males are present with both sexes of either C. fatigans or C. globocoxitus. This is interpreted as due to the operation of different systems of mate recognition. The existence of mate recognition systems governing the complete positive assortative mating which results when either C. fatigans or C. globocoxitus males are present with both sexes of molestus is masked by the effects of differential development. Mate recognition behaviour in molestus females is inferred, however, from the discrimination against molestus males by C. fatigans and C. globocoxitus females. A consequence of the different behaviours responsible for mate recognition is the prediction that molestus can coexist in nature with other members of the C. pipiens group of species with which it is interfertile in artificial crosses. This argues for the reinstatement of molestus as a full species.