NUISANCE MOSQUITO CONTROL

Control efforts & dry conditions have reduced floodwater mosquito numbers; they are averaging in the single to lower double digit numbers. Complaints have been low.

Crews continue to treat floodwater areas with the microbial larvicide’s Bacillus thuringiensis israelensis (Bti) and Bacillus sphericus.

CULEX MOSQUITOES

Culex mosquito numbers are slowly increasing but are below normal for the end of June. Elevated temperatures expected in July will hasten their development as well as the risk for West Nile Virus (WNV). Residents are advised to inspect their properties for stagnant water areas that produce these mosquitoes. Any container that holds water and organic debris for greater than 7 days can produce many of these mosquitoes.

Crews are nearly finished treating backyard and street catch basins with 150-Day Altosid Ingots (methoprene). Other above ground stagnant water mosquito producing sites (detention/retention ponds, ditches, building foundations & container sources) will be treated with the microbial insecticide Bacillus sphaericus or methoprene.

MOSQUITO VIRUS SURVEILLANCE IN ILLINOIS

One human case of WNV has been reported from DuPage County.

NWMAD has tested 255 batches of mosquitoes for arboviruses. Collections have been from throughout the NWMAD territory. Two RT-PCR tests (by the Illinois Natural History Survey) of Culex mosquitoes from Wheeling and Elk Grove Village (collected 6/13-14 & 6/22-25, respectively) were positive for WNV. Those same samples tested with the VecTest were negative for WNV indicating the virus levels for those mosquitoes were low, typical this time of the season. Mosquito batches testing positive in the District are posted at the NWMAD website www.nwmadil.com/VECTEST1.htm.

4^TH OF JULY MOSQUITO OUTLOOK:

Daytime biting mosquitoes (primarily floodwater Aedes vexans) are expected to be light. The 0.3” rain on the 18-19^th of June is not likely to create any significant biting nuisance at our BBQ’s. The obligate nighttime blood-feeding Culex have been increasing in number but are still below average for this time of the season. Because Culex mosquitoes are out there residents are still advised to wear insect repellents and avoid peak mosquito periods. Please visit www.nwmadil.com/protecting yourself.htm for additional mosquito avoidance advice!

REDUCING THE RISK OF MOSQUITO BITES:

Avoid outdoor activity if possible from dusk to dawn when the mosquitoes bite the most. If you do go out wear light colored protective clothing and insect repellent (always read label warnings and directions). Make sure mosquitoes do not enter homes through unscreened or broken doors or windows. Residents are encouraged not to create mosquito harborage areas. Make sure tall grassy areas are trimmed and other vegetation is cut back. If plants must be watered do so in the morning so the vegetation and soil has a chance to dry making it less attractive to mosquitoes. Empty any containers holding stagnating water like tire casings, birdbaths, flower pots and barrels that may produce mosquitoes. Un-maintained swimming pools may produce thousands of mosquitoes. Call the District to report stagnant water areas that remain wet for more than 7 days. Additional mosquito avoidance/control practices may be found at the District’s website: www.nwmadil.com

Mike Szyska

Director