1. Mosquitoes in Neston, Cheshire Michael Clarkson, Mike Service and Cathy Glover National Centre for Zoonosis Research, Liverpool Veterinary School

2. We are grateful to many staff at Leahurst and their families who collected mosquitoes for identification, often involving pain! We thank the following for help and advice: Malcolm Bennett Tom Henderson Christian Setzkorn Staff of the Environmental Protection Unit, Ellesmere Port and Neston Borough Council

3. Many complaints of mosquito bites in the Neston area were received by the Local Authority in 2005 and 2006 Leahurst River Dee tidal marsh 1 km

4. Dee marshes at Parkgate, Neston looking towards Wales These tidal marshes are an internationally recognised site, being both an SSSI and an EU Special Area of Conservation They are also an excellent breeding site for Aedes detritus

5. Surveys were done in 2007 and 2008 by two methods – traps in gardens and mosquitoes collected by Leahurst staff recruited from our email list The Local Authority placed traps in residents’ gardens and sixth form students at the local comprehensive school had traps in their gardens. Three different types of trap were used Although the traps were useful for public relations, the mosquitoes collected by staff were in better condition, more numerous and more widely distributed geographically

6. CDC light-trap BG-Sentinel trap Midg-it trap

7. Type of Trap Aedes detritus Culex pipiens Culiseta annulata CDC light- trap 12613 BG trap, no CO2 0565 BG trap with CO2 150405 Midg-it trap 95283 Estimate of relative efficiency of traps

9. Map showing distribution of 3 species caught

10. Culex pipiens group in United Kingdom consists of three species which cannot be distinguished morphologically. Culex pipiens and Culex torrentium feed only on birds. Culex pipiens group mosquitoes transmit West Nile Virus in Europe and USA Culex molestus bites mammals including humans and also occasionally birds. Molecular methods for differentiating these species are being developed.

11. Mol wt markers Cx pipiens Ae detritus 310 194 A PCR technique described by US workers has been used to distinguish Cx pipiens group mosquitoes These studies suggest that our mosquitoes are Cx pipiens s.s. Cx molestus