Insects represent the largest component of Australasia’s animal diversity. While the uniqueness and conservation needs of Australia and New Zealand’s vertebrates are generally understood, the importance of our insects and the threats they face are less appreciated. Some groups, including locally endemic butterflies and flightless giants, such as giant weta, are important for raising public awareness of insect conservation. However, our understanding of how broad processes influence insect populations and communities is in its infancy. Part of the issue is due to a complete lack of knowledge of the biology of the vast majority of insect species, as most insects in Australasia remain undescribed. In this chapter we discuss insect biodiversity in Australia and New Zealand and discuss both insect species and diversity conservation, contrasting patterns in Australia and New Zealand. We then discuss some of the major threats facing insect species and diversity, specifically focussing on the impacts of habitat loss and fragmentation, predation by invasive rodents and climate change. Lastly, we discuss interactions between insects and humans including the provision of ecosystem services by insects in an agricultural context, human consumption of insects (entomophagy) and concerns surrounding the lack of taxonomic expertise for insects in Australasia.
Insect biodiversity in Australia and New Zealand
The uniqueness of the Australian fauna has been known for centuries, and since the first European explorers returned from voyages to the Antipodes, naturalists have remarked on the diversity of Australasian life, and its peculiarity. While most people are familiar with the stories of European incredulity when faced with a stuffed platypus or kiwi, many may not appreciate that the insect fauna of Australia and New Zealand is equally unique, and far more diverse. The first insect formally identified in Australia was the charismatic Botany Bay weevil (Chrysolopus spectabilis) by Joseph Banks who accompanied James Cook in 1770, but since then over 60 000 species have been described from Australia and New Zealand. Estimates for the species-richness of Australia’s terrestrial insects range between 84 000 species (CSIRO, 1991) and 205 000 (Yeates et al., 2003), of which 75% are yet to be described, and given a name. New Zealand has lower diversity owing to its smaller landmass and its more temperate latitudinal range, but still holds an estimated 20 000 species of insects with 10 000 still requiring description (Cranston, 2010).