West Nile Virus

Larval Mosquito Surveillance

Catch Basin Larviciding ProgramMosquito Larvae
Regionally and municipally-owned roadside catch basins throughout the Region are monitored for larval mosquito activity annually beginning mid-May of each year.  Three catch basin treatments are conducted during the WNV season with the first catch basin treatment traditionally occurring in mid-June and subsequent treatments occurring mid-July and mid-August.  To maximize the effects of the larvicide, the treatments are separated by a maximum of twenty-one (21) days.

Standing Water Larviciding Program
Beginning in mid-May, areas of standing, stagnant water are assessed as WNV vector larval mosquito development sites. Where remediation of identified larval mosquito development sites is not possible, a biological larvicide is applied based on the results of a local risk assessment.

For more information, please refer to Facts About... Stagnant Water & Mosquito Prevention and Facts About... Larviciding