Mosquitoes and Flooding

These "floodwater" mosquitoes are typically nuisance related but are not good at picking up and transmitting West Nile Virus, therefore Fraser Health does not recommend management of these populations for human health protection.  Some communities in Fraser do have nuisance mosquito control programs in place, mostly to reduce the annoyance to area residents.

The mosquitoes most capable of transmitting WNv, Culex pipiens and Culex tarsalis are generally called the "vector" mosquitoes.  These mosquitoes like to lay their eggs in smaller bodies of stagnant water.  Should flooding contribute to the creation of pools of water, and these pools remain for extended periods, there is potential for vector mosquitoes to find and use these pools for breeding.  Local governments in Fraser Health have all agreed to monitor surface water breeding habitat on public lands that might contain vector mosquito larvae and treat that water with environmentally safe bacterial pesticides if and when the vector mosquitoes are identified. 

Personal protection continues to be the best way to protect oneself from mosquito bites, and eventually West Nile Virus.  Wearing approved mosquito repellents, proper clothing and protecting your home by screening all household windows and doors should always be considered the first line of defense against mosquitoes looking for a meal. 

The reduction of mosquito breeding habitat is a good way to improve personal protection, and following Integrated Pest Management techniques should include reducing the places where they live.  Bacteria-based larvicides such as Bti (Aqua Bac™) are available for sale and give homeowners another way to reduce mosquitoes on their property.  This may be a good option for concerned homeowners to address isolated pools of water on their fields left by flooding, especially if the receding water remains longer than a week or two.