Abstract
Wolbachia are common intracellular bacteria that are generally found in arthropods including a high proportion of insects and also some nematodes. This intracellular symbiont can affect sex ratio with a variety of reproductive anomalies in the host, including cytoplasmic incompatibility (CI) in haplodiploides. In this study, we questioned if the parasitoid wasp, Habrobracon hebetor (Hym.: Braconidae), which is one of the most important biological control agents of many lepidopteran larvae, is infected with Wolbachia. To test this, DNA was extracted from adult insects and subjected to PCR using specific primers to Wolbachia target genes. The results showed high rate of Wolbachia infection in this parasitoid wasp. To find out the biological function of Wolbachia in H. hebetor, we removed this bacterium from the wasps using antibiotic treatment (cured wasps). Results of the crossing experiments revealed that Wolbachiainduced CI in H. hebetor in which cured females crossed with infected males produced only males, while in the progeny of other crosses, both males and females were observed. Also, our result showed that the presence of Wolbachia in the females increased fecundity and female offspring of this parasitoid wasp. However, the presence of Wolbachia in the males had no significant effect on the fecundity and female production, but might have incurred costs. We also investigated the effect of Wolbachia on mate choice and found that Wolbachia affects mating behavior of H. hebetor. Together, we show that Wolbachia induce CI in H. hebetor and affect host mating behavior in favor of its transmission. Wolbachia utilize these strategies to increase the frequency of infected females in the host population.