HR: 09:15h
AN: NB51A-04    [Abstracts]
TI: The Widespread use of Methoprene for the Prevention and Control of West Nile Virus in Ontario, Canada: Is it Impairing our Streams?
AU: * Fletcher, R
EM: rachael.fletcher@ene.gov.on.ca
AF: Ontario Ministry of the Environment Biomonitoring Section, 125 Resources Road, Etobicoke, ON M9P 3V6 Canada
AU: Baker, S L
AF: Ontario Ministry of the Environment Biomonitoring Section, 125 Resources Road, Etobicoke, ON M9P 3V6 Canada
AU: Hayton, A
AF: Ontario Ministry of the Environment Biomonitoring Section, 125 Resources Road, Etobicoke, ON M9P 3V6 Canada
AB: Catch basins have been identified as a major breeding location for the mosquito Culex pipiens, a primary vector for the spread of West Nile Virus in Ontario. Methoprene, an insect growth regulator, has been applied extensively in catch basins to combat the spread of mosquito populations. Since 2003, an estimated 1 million catch basins located around the Canadian shores of Lake Ontario were treated with 0.7g of 30-day, slow release methoprene pellets (4.25% active ingredient). Although studies have shown that methoprene breaks down quickly in the environment and is relatively non-toxic to mammals and fish, the large quantities being applied across Ontario raise concerns over the effects methoprene and its metabolites may have on non-target aquatic insects. The receiving streams of selected catch basins where methoprene was applied regularly were studied to assess the effects of methoprene application on stream macroinvertebrates. Although methoprene was not detected in the receiving waters, some changes in the community assemblages were observed. Many of the observed changes could be attributed to seasonality, however, percent Ephemeroptera, Plecoptera and Trichoptera (EPT) tended to be lower downstream of the storm sewer discharge compared to upstream and pre-application.
DE: 1871 Surface water quality
DE: 4857 Pollution
DE: 9810 New fields (not classifiable under other headings)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly