Observations on the ecology and behaviour of the New Zealand giraffe weevil (Lasiorhynchus barbicornis)

Abstract

The New Zealand giraffe weevil (Lasiorhynchus barbicornis) is an endemic, wood-boring insect (Coleoptera: Brentidae). Despite being a large and charismatic species, very little is known about its life history. We conducted observations of L. barbicornis behaviour and ecology in a wild population west of Auckland and developed a marking system in preparation for a future large-scale observational experiment. We found that giraffe weevils were easily located and observable in the field, and therefore provide a useful model species for behavioural ecology. Adults were found to aggregate, copulate and oviposit on 17 host tree species from 16 families, extending the current host plant association records for this species. A breeding experiment determined that the length of the larval stage is a minimum of 2 years and that the population at emergence has an unbiased sex ratio. © 2014 © 2014 The Royal Society of New Zealand.