Extensive larviciding program underway in response to heavy rainfalls

WINNIPEG - May 29, 2007- Today, the Insect Control Branch announced that a full-out larviciding program is underway in response to the heavy rainfall. The Branch is now utilizing all resources to treat standing water sites in Winnipeg and the surrounding 10 km treatment area. All sites that have mosquito larvae will be treated.

Over the past week, the City has received between 70 and 100 mm of rain with the southeast part of the City receiving the most rainfall. In light of this significant amount of rainfall, the AFA (Adulticiding factor analysis) guideline has been moved from low to medium.

The heavy rains have resulted in above normal soil moisture conditions which have created large pools of standing water, ideal for mosquito larva development. Surveillance data indicates significant mosquito larvae which are currently in the first and second instar (stage). Approximately 75% of all sites are now holding water. This is a significant increase from last week when only 25% of sites were holding water. About 24,000 hectares of potential water sites now need to be checked for larva and treated if larva are found.

It is also important that everyone pitches in and eliminates standing water on their property. Property owners are encouraged to help “Fight the Bite” by taking any one of the following steps to eliminate standing water on their properties:

Dump It! – containers
Drain It! – eavestroughing or unused containers
Cover It! – rain water collection containers
Fill It! – low-lying areas
Treat It! – biological larvicides can also be purchased at local home and garden centres.

With the change of the AFA to medium, the Insect Control Branch will also utilize residual treatments as part of an integrated nuisance mosquito approach. Residual treatments will be applied onto localized areas of long grass and borders of bushes to kill adult mosquitoes in their resting areas. This part of the program will begin once adult mosquitoes emerge.

The helicopter program accounts for about 80% of larviciding operations. Helicopters apply larvicides to large bodies of standing water and standing water sites which are not easily accessed by ground crews. Approximately 150 staff are dedicated to surveillance and larviciding activities and crews are working 7 days a week.

Interested individuals may acquire more information by contacting the City’s Bugline at 311, Monday to Friday from 8:30 a.m. to 4:30 p.m. or by visiting the City’s Insect Control website at Winnipeg.ca/bugline.