Abstract Strepsipterans are endoparasitic insects that parasitize hosts belonging to seven insect orders. They develop inside the host body, and adult males emerge to become free‐living. To date, male emergence has been observed only in the families Mengenillidae, Xenidae and Elenchidae (Order Strepsiptera), which parasitize silverfishes, hornets and planthoppers, respectively. In these cases, emergence sites on host bodies are exposed. However, in some strepsipterans, males emerge from the arthrodial membrane on the dorsal side of the abdomen, which is covered by the host's wings. Such emergence behavior has not been reported previously. Here, we report how Blissoxenos esakii (Strepsiptera: Corioxenidae) emerges from this covered site. Blissoxenos esakii was collected from nine locations in Tsukuba City, Japan, and reared in the laboratory until male emergence. Ten males successfully emerged from their hosts, and emergence was observed in four cases, including one case in which a host was parasitized by two male B. esakii . In all four cases, hosts raised their wings during male emergence, a behavior not observed in unparasitized hosts, thereby enabling B. esakii to emerge. Further investigation is needed considering the possibility that this behavior constitutes host manipulation and a common action among the hosts parasitized by corioxenids, which emergence site is covered by the host's wings.
Ishikawa et al. (Wed,) studied this question.