Aedes notoscriptus A native of Australia (exotic to NZ). Photo by Richard Toft (Landcare, Nelson)

Research Profile

Mosquitoes in Karori Wildlife Sanctuary

Amy Snell-Wakefield, BSc, BEnvTox Hons, PhD
Ecology and Health Research Centre
Department of Public Health
Wellington School of Medicine
University of Otago
amysnell@gmail.com

Ecology and Health Research Centre
Department of Public Health
Wellington School of Medicine
University of Otago

Larval Dipping at Taylor Wetland (Photo J. Wakefield)

Humans are very good at changing the environment. This is widely recognised as a key factor in the resurgence and spread of mosquito-borne diseases. People move around, change the vegetation and replace native species with farm animals and cultivated plants. This is allowing nuisance and potential disease-bearing insects to move into new habitats, in particular the more closely settled farming areas, and areas around towns, especially where there is a mix of housing and forest.

New Zealand has 16 species of mosquito, 12 native and four exotic. The exotic mosquitoes in New Zealand can carry arboviruses (arthropod-borne viruses) that cause human illness in other countries.

Amy's research at Karori Wildlife Sanctuary is part of a wider project that compares mosquito species present and their distribution in urban and agricultural areas and in native forest — in the Wellington Region. This new information is making it possible to assess the potential risks to human health from mosquitoes.

Profile Amy Snell After completing a B.Sc and B.Environmental Toxicology Honours at the University of South Australia, Australia and working for the Mosquito Research Laboratory at the University of SA. Amy moved to NZ to take up a PhD scholarship at the University of Otago. She completed her PhD on the Identification and distribution of endemic and exotic mosquitoes in New Zealand, which included a case study of land-use and mosquito distribution in the Wellington Region and a pilot health promotion project. Photo by Mary McIntyre: Checking a carbon-dioxide baited miniature light trap.

Mosquito trapping was undertaken in each of three land use types at Karori (including native forest in the Sanctuary, Belmont and Waikanae). Mosquitoes were trapped at these sites (9 locations) every two weeks September–April, 2002/03 and 2003/04, using carbon-dioxide baited miniature light traps (12 traps per site, total 36). Traps were set approximately 1–2 m above ground level, 1–2 hours before sunset and collected the following morning. This method served to catch a variety of mosquito species that have dawn/dusk or night-time host-seeking behaviour.

Only two species of mosquito were collected in Karori Wildlife Sanctuary. These were the native Culex pervigilans and the exotic Aedes notoscriptus, which is now well established within the Wellington Region, especially in urban areas.

Papers and Presentations

Snell, A.E. and McIntyre, M. (in prep). Land-use, mosquito diversity, relative abundance and distribution of mosquitoes in the Wellington Region, New Zealand.

Snell, A.E. 2005. Identification keys to larval and adult female mosquitoes (Diptera: Culicidae) of New Zealand. New Zealand Journal of Zoology 32: 99-110.

Snell, A.E., Derraik, J.G.B. and McIntyre, M. 2005. Maorigoeldiaargyropus Walker (Diptera: Culicidae): is this another threatened endemic species? New Zealand Entomologist 28: 95-99.

Snell, A.E. 2007. Post-establishment mosquito survey of a constructed wetland in the Karori Wildlife Sanctuary (Technical Report) (pdf format, 786 kB)

Related Links

• Ecology and Health Research Centre at Wellington School of Medicine
• Ecology, Conservation and Biodiversity Research Group at Otago University

Acknowledgments

Amy received a post-graduate scholarship from the University of Otago. Shane Geange assisted in the field. Thanks also to Dr. Mary McIntyre.