The biologies of two species of weta endemic to the Snares Island : Zealandrosandrus subantarcticus Salmon (Orthoptera : Stenopelmatidae) and Insulanoplectron spinosum Richards (Orthoptera : Rhaphidophoridae)

Abstract

The life histories, behaviour, diet, habitat, and diurnal activity patterns of two species of Snares Island weta, Zealandrosandrus subantaraticus and Insulanovlectron spinosum, are presented. The males and females of Z. subantarcticus had 12 instars. The males of I. spinosum had 9 instars while the females had 10 instars. Eclosion, moulting, inter- and intraspecific interactions, oviposition, and cannabalism are described. The diet of both species included arthropods, plant material, and dead seabirds. Descriptions of abdomina-femoral stridulatory apparatus for both species are presented. Reproductive parameters and sex ratio of both species were examined. Diurnal activity patterns showed an increase in activity half an hour after sunset and a decrease half an hour before sunrise for both species. These species of weta from the Snares Island showed similarities in aspects of their biologies to those of mainland species