Decision-making in a bisexual line and a thelytokous Wolbachia-infected line of Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) regarding behavior toward their hosts.

Abstract

The use of thelytokous Wolbachia-infected Trichogramma (parasitic wasps) has long been considered as a way to enhance the efficacy of biocontrol. However, Wolbachia can affect the host physiology. We compared decision-making between bisexual and thelytokous Wolbachia-infected lines of Trichogramma dendrolimi Matsumura regarding behavior toward fresh and old eggs of Corcyra cephalonica at 25 ± 1 °C and 70 ± 5% relative humidity. The behavioral patterns and sequences of the two lines were basically the same. The durations of various behavioral patterns and values of fitness indicators of the bisexual line on fresh eggs were generally significantly shorter and better, respectively, than on old eggs, whereas the thelytokous line behaved similarly toward the two types of eggs, and differences in most fitness indicators between fresh and old eggs were not significant. On fresh eggs, the durations of various behaviors in the bisexual line were generally significantly shorter than in the thelytokous line and the fitness indicators were generally significantly better. Wolbachia affected the fitness of T. dendrolimi negatively. The potential of the thelytokous line as a biocontrol agent would not be as good as that of the bisexual line when decision-making only is considered. Therefore, further evaluations need to be carried out before the thelytokous line can be used in practical biocontrol. © 2018 Society of Chemical Industry.