NORTHWEST MOSQUITO ABATEMENT
DISTRICT
147
Phone: (847) 537-2306
Fax: (847) 537-2583
www.nwmadil.com
Mosquito
Update
May 27, 2005
PRESENT CONTROL STATUS:
NUISANCE
FLOODWATER MOSQUITOES
Rains
of approximately 1” between the 18th and 20th
of May produced a below average floodwater
mosquitoes (Aedes vexans) hatch.
Light traps currently monitoring these mosquitoes are still averaging in
the low single digit counts. Biting
mosquitoes produced from these rains are likely to start increasing around the
Memorial Day holiday and thereafter but should not be very noticeable or
annoying unless we get more rains. Some areas in the District near wetlands and
heavily vegetated areas may experience slightly more problems.
Numbers of these mosquitoes
will be reduced in the District due to extensive methoprene larviciding
treatments already in place by our crews.
CULEX
MOSQUITOES
Culex mosquito numbers have been building
as indicated by our gravid traps. Thus
far numbers are similar to what we observed in the 2004 season due to below
normal temperatures. Culex mosquitoes are of concern since
they are the type more frequently found infected with WNV. Most of the Culex mosquitoes produced this early in the season are from above
ground stagnant water sites like containers, ditches, retention/detention
ponds, un-rimmed abandoned tires, clogged rain gutters, flower pots, etc. As the weather warms up underground production
areas like the street catch basins & backyard drainage basins become
important Culex production
areas. The District also treats the
aforementioned water areas with methoprene and microbial insecticides to
control this medically important group of mosquitoes. It is very important that residents of the District inspect their own
property for stagnant water that can produce these mosquitoes, regularly, on a
weekly basis during the months of May- September.
MOSQUITO VIRUS
SURVEILLANCE IN
The Illinois Department of
Public Health has reported infected mosquitoes in
To date NWMAD has tested
(VecTest) 27 Culex mosquito batches throughout the District. All mosquito batches were negative for West
Nile Virus,
CATCH BASIN TREATMENTS:
NWMAD will be beginning treatment of catch basins with the insect growth regulator methoprene (a.k.a. Altosid). The formulation of briquette we place in the basins will provide mosquito control as long as the basins are not cleaned out so that the briquette is removed. Rainfall and additional water (i.e. lawn sprinkling) will not reduce the effectiveness of the treatment. Altosid briquettes are not harmful to people or pets. Basins are only treated if they have sumps or pits that collect and hold water for 10 days or longer. For more information on methoprene (Altosid) visit the following website: http://www.epa.gov/pesticides/factsheets/larvicides4mosquitos.htm.
NOTE: Residences that we treat backyard catch basins will receive a yellow door hanger indicating that we performed the treatment as well as additional mosquito prevention suggestions and the District’s phone number for additional information.
DEAD BIRD SURVIELLANCE INFORMATION:
NWMAD has received 10 dead bird reports via our dead bird reporting website. No dead birds infected with WNV have been reported in the NWMAD District as of yet. 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 may phone the Cook County Department of Public Health at (708) 492-2035.
MIDGE REPORTS:
What looks like a mosquito, flies in swarms around dusk and may be so numerous that they can cover the sides of houses-MIDGES. These insects are commonly mistaken for mosquitoes and usually reported April, May & June by alarmed residents. Midges have no biting mouth parts so they can not blood feed. The larvae are aquatic like mosquitoes and are commonly found in stagnant polluted water areas. Like Culex mosquitoes they can also be found in containers (i.e. pails, tires, bird baths, clogged rain gutters) or in any water area rich with organic matter. Adult midges may also travel up to a quarter mile from their breeding sites. There are no satisfactory control measures for midges although some insecticide barriers and space sprays may provide temporary relief. Methoprene, an insect growth regulator used to control mosquito larvae at NWMAD, is effective against midges. However, midge production sites may be overlooked by normal mosquito abatement surveillance due to the fact that mosquito larvae are sampled at the water surface and midges are primarily found in organic bottom sediment. Fortunately, adult midges live for only about 10 days. Residents may reduce nuisance midge problems by eliminating stagnant water on their properties and limiting light sources (i.e. close window curtains and turn off porch and flood lights) that attract the insects to their properties around dusk till about 45 minutes after sunset.
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 for 7 days or longer like: tire casings, birdbaths,
flowerpots and barrels that may produce mosquitoes. Neglected 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