Comparison of the weevil fauna (Coleoptera: Curculionoidea) in two tussock grassland sites in Otago, New Zealand)

Abstract

Invertebrates exhibit exceptional levels of diversity and endemism in New Zealand where, historically, they have received only limited consideration in land management decisions. Many species exist outside the habitats typically set aside for conservation, such as lowland to subalpine Chionochloa tussock grasslands. These habitats are under‐represented as protected areas due to their modified state and their invertebrate fauna is poorly understood. Compiling inventories has been suggested as one means of facilitating a greater awareness of invertebrate diversity and ecology. This study presents an inventory of Curculionoidea recorded during a single quantitative sampling event in mid summer 2001, from two Otago Chionochloa tall‐tussock grasslands. Species diversity is compared with that of other southern South Island tussock grassland areas, and notes on weevil ecology and distribution are given. Of the 35 species known from the two sites, only 17 were recorded from samples taken in January 2001, demonstrating the importance of factors such as seasonality and microhabitat to study design. Genera recorded showed affinities with those of grassland studies in neighbouring ecological districts. Almost 50% of the species collected from the two sites were undescribed; this not only limits the capability of land managers to compare areas under consideration for protection or other land uses, but also indicates an abundance of unrecorded and unprotected biological diversity. © 2003 Journal of the Royal Society of New Zealand.