Mosquitoes in Karori Sanctuary
Back to Research
Mosquito.
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
Larval dipping at lower lake wetland.
Photo by 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.
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.
Another undertaking in Karori Wildlife Sanctuary was the post-establishment mosquito survey of a constructed wetland to determine if any mosquito species colonised this new habitat (refer to technical report).
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.
Acknowledgements
Amy received a post-graduate scholarship from the University of Otago. Shane Geange assisted in the field. Thanks also to Dr. Mary McIntyre.
Profile - Amy Snell
Checking a carbon-dioxide
baited miniature light trap.
Photo by Mary McIntyre
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.
Published October 2004, updated May 2007
Back to Research