A preliminary survey of the insects collected using mushroom baits in native and exotic New Zealand woodlands

Abstract

The insects associated with the fruiting bodies of macrofungi are an important component of woodland biodiversity. A preliminary survey of the woodland insects associated with macrofungi was undertaken using commercial mushrooms as a standard bait. Adult insects were collected in different categories of woodland (native mixed forest; native Nothofagus forest; exotic conifers; restoration/conservation areas) at 17 sites on the South Island of New Zealand. In total, 2429 specimens were collected, consisting of 1282 Coleoptera, 1022 Diptera and 125 Hymenoptera. Several newly-described genera and species of Diptera were recorded, indicating that the use of unconventional collecting techniques such as bait trapping can be useful in augmenting site-species inventories.

Different orders of insects showed different patterns in terms of their abundance and species richness amongst the different categories of woodland. Coleoptera were more abundant and species-rich in native mixed and Nothofagus forests than in plantations of exotic conifers, and were very poorly represented in urban conservation/restoration sites. However, Diptera and Hymenoptera were most abundant and diverse in stands of exotic conifers such as Pinus radiata plantations and urban conservation sites. The results indicate that monoculture plantations of exotic tree species can compare favourably to native forests in terms of richness and diversity of insect faunas and, although faunistically poor, urban reserves can also play a valuable role in maintaining indigenous invertebrate biodiversity at a local level.

Some species, such as the agyrtid beetle Zeanecrophilus prolongatus, were found primarily in native forest, and the occurrence of such species might be utilized as indicators of site quality in remnant patches of woodland.

Keywords:

• Conservation
• Diptera
• forests
• fungi
• parasitoids