NORTHWEST MOSQUITO ABATEMENT DISTRICT

147 W. Hintz Rd.

Wheeling, IL. 60090

Phone: (847) 537-2306

Fax: (847) 537-2583

www.nwmadil.com

 

Mosquito Update

July 22, 2009

 

PRESENT CONTROL STATUS:

 

NUISANCE MOSQUITOES

Nuisance floodwater mosquitoes (Aedes vexans) are decreasing due to ongoing control efforts and an aging population.  This trend is expected to continue as long as no significant rainfalls hatch more eggs of this mosquito and migration of mosquitoes from flood areas outside of NWMAD is limited (i.e. prevailing winds).   Unseasonable cooler temperatures have also helped reduce annoyance levels of the floodwater mosquito. 

 

Crews are continuing to treat infested water areas for the developing mosquito larvae with methoprene, MMFG & Bti after each rainfall. 

 

CULEX  MOSQUITOES

Culex mosquito numbers are low compared to prior WNV years this time of the season as indicated by gravid traps.  Residents of the District are still advised to inspect their properties for stagnant water filled containers that may produce these types of mosquitoes.  Examples of mosquito production areas encountered by homeowners can be viewed at: http://www.nwmadil.com/breeding sites1.htm. 

 

Crews are currently treating stagnant ground surface water sources with methoprene pellets, MMFG, Bti & Bacillus sphericus. Catch basin treatments are near completion.  Culex pipiens larvae have been prevalent in ditches, culverts and other stagnant water areas after rainfalls and these are being treated at the same time as the nuisance mosquitoes after rainfalls.

 

ADULTICIDING (NIGHT SPRAYING):

Crews have completed 1 pass of adulticiding through the entire District and a 2nd pass in the heavily infested floodwater areas based on our surveillance traps (primarily wooded areas and communities surrounding forested areas). 

 

Director’s note: trap surveillance for the floodwater mosquito indicate that as we entered a dry-down (lack of significant rainfall) during the first half of July, surviving mosquitoes tend to retreat into heavily forested areas where prevalent vegetation provides more humid conditions preferred by this mosquito. This in combination with the cooler evening temperatures decrease the efficiency of our adulticiding control efforts when the mosquitoes prefer to stay in heavier vegetation which our insecticide has trouble penetrating. Normally, during cool evening temperatures floodwater mosquitoes tend to remain inactive in the vegetation unless a person (or other potential blood meal) disturbs their resting areas and kick-starts their blood feeding activity. Similarly, the same thing may happen during the daylight hours when residents become active in shaded areas or tend their gardens and disturb the mosquitoes that would not normally be flying under bright sunlight unless there is a potential nearby blood meal.  For these reasons adulticiding has been suspended until mosquito numbers increase in our traps or WNV activity increases in the mosquitoes. 

 

MOSQUITO VIRUS SURVEILLANCE IN ILLINOIS

Mosquito batches testing positive for these viruses in the NWMAD territory will be posted at the following website address: http://www.nwmadil.com/VECTEST2009.htm .  Currently NWMAD has tested 393 batches of mosquitoes for West Nile virus (WNV).  Mosquitoes testing positive for WNV have been collected from Rolling Meadows, Barrington & Hoffman Estates.  No subsequent WNV infected mosquitoes have been detected for about two weeks now. 

 

No human cases of WNV have been reported in the State of Illinois in 2009. 

 

The Illinois Department of Public Health has reported that 26 batches of mosquitoes tested positive for West Nile virus in 10 counties thus far in 2009. Thus far, in Cook County WNV infected mosquitoes have been found in Wilmette, Evanston, Rolling Meadows, Barrington, Skokie, Northbrook, Palos Hills, Hillside and Glenview.  More information about WNV can be found on the state’s website www.idph.state.il.us/envhealth/wnv.htm or by calling 217-782-5830.  The State’s website also has other valuable resource links on WNV, pesticides and mosquito control.

 

NWMAD WEBSITE:

Report 10-day standing water problem: http://www.nwmadil.com/water source rpt.htm

Report sick/dead birds or other animals: http://www.nwmadil.com/Dead Birds.html

Check night time mosquito spraying schedules:  http://www.nwmadil.com/nitespry_map.html

 

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, loose fitting, 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 unnecessary 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 for 5 days or longer like: tire casings, birdbaths, flowerpots and barrels that may produce mosquitoes. Make sure rain barrels or other storm water runoff cisterns are fitted properly to gutters when installed, well screened from egg-laying adult mosquitoes and free of detritus or organic material.  Neglected swimming pools may produce thousands of mosquitoes.  Call the District to report large stagnant water areas that remain wet for more than 7 days.

 

 

 

 

 

 

 

 

 

PLEASE FORWARD THIS INFORMATION TO APPROPRIATE DEPARTMENTS AND AGENCIES.

 

 

 

 

Mike Szyska

Director