NUISANCE MOSQUITO CONTROL

Cooler temperatures and control efforts have reduced floodwater mosquito numbers, they are averaging in the single to lower double digit numbers. As warmer temperatures and dryer conditions continue remaining floodwater mosquitoes will retreat into the more humid woodland and tall grass areas in the vicinity of ponds and standing water. Remaining floodwater mosquitoes produced at the end of May and beginning of June should be reaching the limits of their life spans. The last floodwater mosquito hatch produced was on June 21^st and was considered a minor brood that was suppressed by ongoing larviciding efforts.

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

CULEX MOSQUITOES

Culex mosquito numbers have been reduced due to control efforts and cooler temperatures. Elevated temperatures 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.

ADULTICIDING (Night Spraying Operation):

Nighttime spraying for adult mosquitoes has been discontinued due to low trap counts and cooler evening temperatures. The entire District has been sprayed once and communities along the Des Plaines River twice. Current weather predictions for the 4^th of July holiday suggest that mosquito annoyance during that time will be moderate unless temperatures are above normal.

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

STREET & BACKYARD STORM SEWER TREATMENTS:

Street storm sewer treatments are complete. Various Villages have recently provided us with additional backyard storm sewer locations that are currently being treated.

MOSQUITO VIRUS SURVEILLANCE IN ILLINOIS

NWMAD has tested 119 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. Those same samples tested with the VecTest were negative for WNV indicating the virus levels for those mosquitoes were very low. Subsequent tests of mosquitoes from those same traps tested with the more sensitive RT-PCR were all negative thus far. We will continue to closely monitor our surveillance traps in those areas for further distribution of the WNV. 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 270 dead bird reports. Four dead birds (Barrington, Palatine, Streamwood, Inverness) were tested and reported infected with WNV. Thus far the breakdown of dead birds include: 34 sparrows, 33 robins, 25 crows, 20 grackles, 13 starlings, 8 blue jays, 5 cardinals, 3 flickers, 2 finches, 2 pigeons, 2 chickadees, 2 redwing black birds, 2 wrens, 1 cowbird, 1 duck & 110 unidentifiable or unknown birds. Additionally, 4 squirrels, 2 rabbits and 1 ground squirrel were reported. Most all of these birds were not tested for WNV but comparing previous bird death records (dead gray squirrels) and clusters of dead crows and blue jays are usually an additional indication of a possible developing WNV problem. 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 (PLEASE NOTE THIS NUMBER HAS CHANGED SINCE THE LAST NEWSLETTER).

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.