Mate choice in the parasitoid Lysiphlebus fabarum is conditioned by host species and influences progeny fitness

Abstract

Abstract We used the aphid parasitoid wasp, Lysiphlebus fabarum (Hymenoptera: Braconidae) reared on host aphids Aphis fabae (Hemiptera: Aphididae) and Aphis gossypii to examine whether or not mating preference can be conditioned by the host species on which the wasps were reared. The effect of the parental hosts on the fitness of the progeny was also examined. The results revealed that male and female wasps reared on one host species preferred each other as mates than those individuals reared on a different species. This was demonstrated by counting the number of mating successes and the olfactory response of males to the odor of females that developed in Aphis fabae or A. gossypii. The results also revealed that conditional mate choice mediated by a host species increased the fitness of the female progeny (i.e. larger bodies, shorter developmental time and higher egg load with larger eggs), and led to a higher female sex ratio. Because the particular host species confers fitness on the developed wasps, the fitness traits appear in the progeny when both parents are reared on one host species, but not in the progeny of two parents reared on different host species.