Parasitoid infection and sexual selection in the beetle Timarcha maritima Perris (Coleoptera : Chrysomelidae)

We investigated the influence of the hymenopteran parasitoid Perilitus sich eli Giard (Braconidae) on the pattern of mating and mate choice processes i n the Chrysomelid beetle Timarcha maritima Perris. In the field, the preval ence of infection was higher in unpaired males and females than in paired i ndividuals, although this result was significant only for males. The size o f infected and uninfected individuals was not significantly different. The fecundity was significantly reduced by the infection in females. However, i n experimental conditions males were unable to detect and to avoid infected females as sexual partners. We discuss the possible reasons for this absen ce of preference.