Life cycle, survival rates and longevity of an alpine weta

Although reproductive and behavioural studies have been conducted on captive tree weta, there have been very few ecological field studies of any of the weta species involving free-ranging, marked individuals. The mountain stone weta (Hemideina maori) is a tree weta that lives on rock tors in the alpine region of the South Island of New Zealand. Over three seasons each of 480 adults and 789 juveniles was individually marked on four large and 14 small tors to gather baseline information on aspects of H. maori’s life cycle and life history. Seasonal patterns were seen in the appearance of the smallest nymphs, moulting, and in the survival and recruitment of adults. Some marked juveniles were recaptured after 10 or more months, with a maximum interval of 14.1 months, indicating that instar intervals can be exceptionally long. Adult males and females had similar survival rates and often lived for 2 or 3 breeding seasons. Relatively high recapture rates (~60–70%) and long life spans make adult H. maori amenable to modern mark-recapture analyses using the programme MARK. We believe this research will be a useful template for further mark-recapture studies such as those to verify life history characteristics of endangered species of weta or the effects of secondary poisoning on invertebrates.