NUISANCE MOSQUITO CONTROL

Cooler temperatures and control efforts have reduced floodwater mosquito numbers; they are averaging in the single to lower double digit numbers. Nuisance mosquito populations are likely to increase by the beginning to middle of next week due to up to 2 inch rains that fell on the 3^rd of July. This increase in mosquitoes should be moderate due to current control efforts and a fairly consistent dry-down of mosquito producing water areas.

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

CULEX MOSQUITOES

Average Culex mosquito numbers collected from gravid traps have increased due to current temperatures, but, numbers are lower this time of the year compared to 2002. Elevated temperatures will hasten mosquito 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 finished treating known locations of 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.

ADULTICIDING (Night Spraying Operation):

Adulticiding may begin next week, weather permitting, if Culex or nuisance mosquito numbers increase or additional Culex batches test positive for WNV with the VecTest.

Nightly spraying schedules can be viewed at the following website: http://www.nwmadil.com/District_map1.html. Alternately, a recorded phone message describing our scheduled nighttime spray program can be reached at (847) 537-2306 and pressing “5” on your telephone keypad. More information regarding our Adulticiding program may be viewed at: http://www.nwmadil.com/Night Spray info1.html

MOSQUITO VIRUS SURVEILLANCE IN ILLINOIS

No human cases of WNV have been confirmed in 2004. NWMAD has tested 171 batches of mosquitoes for West Nile Virus, St. Louis and Eastern Equine encephalitis. Collections have been from throughout the NWMAD territory. Three TaqMan RT-PCR tests (by the Illinois Natural History Survey) of mosquito batches (Mt. Prospect, Rolling Meadows & Arlington Heights) from May and early June were positive for WNV. Two other batches of Culex mosquitoes, 1 collected in Mt. Prospect (6/30) and the other 1 from Glenview (7/14) tested positive for WNV via the VecTest. If additional mosquito batches test positive for WNV from the same traps or nearby locations NWMAD will engage our adulticiding program, weather permitting. Mosquito batches testing positive for WNV via the VecTest are of significant concern to us because viral levels in the mosquitoes may then be at high enough levels to infect humans. RESIDENTS ARE THEREFORE ADVISED TO PROTECT THEMSELVES FROM BITING MOSQUITOES USING REPELLENTS AND SHOULD AVOID PEAK BITING TIMES! Mosquito pools testing positive in the District are posted at the NWMAD website http://www.nwmadil.com/VECTEST1.htm.

DEAD BIRD SURVIELLANCE INFORMATION:

NWMAD has received 377 dead bird reports. Four dead birds (Barrington, Palatine, Streamwood, and Inverness) tested for WNV by the Cook County Department of Public Health were found infected. Cities, villages and the public are encouraged to report dead birds to our District’s Dead Bird/Animal reporting web page, which can be accessed at www.nwmadil.com. Knowing this information allows our District to better focus our control efforts. The Cook County Department of Public Health is testing dead birds for WNV. Anyone wishing to have recently dead crows and blue jays tested for virus should phone the Cook County Department of Public Health at (708) 492-2650.

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

PLEASE FORWARD THIS INFORMATION TO APPROPRIATE DEPARTMENTS AND AGENCIES.