Our mosquito traps occasionally capture low numbers of Culex tarsalis mosquitoes, the main transmitter of West Nile virus (Wnv) locally. This species is typically found in late July and early August, particularly following hot, dry conditions.
When enjoying the outdoors, wear bug repellent, pants and long-sleeved shirts. Loose-fitting and light-coloured clothing also helps prevent mosquito bites. It's also recommended that homeowners remove standing water on their properties to reduce potential development sites for mosquitoes.
Mosquito activity is based on standard New Jersey light trap data. These traps are commonly used to record changes in abundance of mosquitoes before and after control campaigns and to compare seasonal and annual fluctuations in population. The City has consistent light trap data going back for decades.
As with any other insect trapping techniques, there is an accepted sampling bias. Not all species respond the same to light and it's recognized that the species caught in the traps can be in disproportionate numbers to the size of their actual populations. The trap catches are also heavily influenced by ever changing environmental conditions that affect mosquito flight activity. Each collection date reflects the levels of general mosquito activity captured during the previous one week period.
This Culex graph compares current levels of Culex tarsalis with levels in 2003 when WNv first arrived in the Edmonton area.
Compare recent nuisance mosquito populations with a history of Edmonton mosquito levels. As these graphs show, Edmonton mosquito populations have been much higher in the past.