Main content area

The cost of autotomy caused by the parasitoid fly Blaesoxipha japonensis (Diptera: Sarcophagidae): an interspecific comparison between two sympatric grasshopper host species

Miura, Kazumi, Ohsaki, Naota
Ecological research 2015 v.30 no.1 pp. 33-39
Blaesoxipha, adults, death, grasshoppers, habitats, locomotion, mortality, parasitoids, predators, rearing
In insects, while much is known about how autotomy, the loss of a host’s hind leg(s), affects locomotion, mating and escape from predators, little is known about the effects of such loss on mortality caused by a parasitoid fly in natural habitat. We tested to see if host mortality caused by the parasitoid fly, Blaesoxipha japonensis, was related to the presence or absence of a hind leg(s) in two closely related, sympatric grasshopper species, Parapodisma tanbaensis and P. subastris. After capturing adult grasshoppers of both species in the same three locations simultaneously for 2 years, we assessed whether B. japonensis caused the death of a host by rearing these captured grasshoppers until they died. The results showed that autotomy significantly affected the mortality caused by B. japonensis in P. subastris adults, but not in P. tanbaensis adults. This suggests that the increased mortality caused by parasitoids can be one of the costs of autotomy in P. subastris in its natural habitat, and that the mortality effect caused by B. japonensis in autotomized adults may differ based on behavioral, physiological, and/or ecological factors that differ between these two sympatric Parapodisma species.