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    NWMAD provides mosquito control to 242 sq. miles of northwest Cook County in the townships of: Wheeling, Palatine, Barrington, Hanover, Schaumburg, Elk Grove, Northfield  (NW 6 sq. miles) and Maine.  Night spraying, when scheduled, will begin at sunset and conclude around midnight.  Neighborhoods initially targeted for night spraying will be those areas where West Nile Virus infected humans, horses, birds and/or mosquitoes have been detected and areas with high Culex mosquito numbers.  Currently, NWMAD uses the following criteria for spraying for WNV during the night-time hours:  WEST NILE VIRUS SPRAY CRITERIA

NWMAD uses a rapid diagnostic test called the RAMP  for the detection of West Nile Virus in mosquito batches.  The test indicates if virus is present in the mosquitoes, and because the results are immediate, it allows us to modify our mosquito control priorities as needed.   A mosquito batch is a collection of adult female mosquitoes of the Culex variety that are thought to be the primary group of mosquitoes capable of transmitting West Nile Virus.  Typically, these mosquitoes are produced in stagnant water areas (i.e. catch basins, containers, un-maintained swimming pools, flooded construction foundations, flower pots, tires, ditches, etc).  Culex mosquitoes, unlike typical common, nuisance floodwater mosquitoes, increase rapidly in numbers during dry, hot summers in the Midwest. The aquatic larvae of this mosquito exploit stagnant water areas, which are better protected from evaporation, than open water areas. 

NWMAD will also utilize its night spraying program in severe nuisance mosquito outbreaks.  Typically, these nuisance mosquito problems are caused by our most common floodwater mosquito Aedes vexans.  This mosquito is produced in enormous numbers after significant rainfall.  District information and criteria for spraying at night for this mosquito is:  NUISANCE MOSQUITO SPRAYING

Residents are strongly advised to inspect their property for standing water problems that may produce Culex mosquitoes.  Report any new stagnant water areas (those that retain water for longer than 7 days) to NWMAD by clicking on the following link:  Report Stagnant Water.  Alternately, you can call us at (847) 537 2306 and use the voice mail reporting system by dialing 3 on a touch tone phone.   NWMAD regularly inspects and treats, if necessary, over 5500 catalogued mosquito production water sites in our District during the mosquito season.  Additionally, hundreds of temporary ditches, low areas, tire piles, new building foundations, are also inspected and treated as needed.  Catch basins are treated regularly throughout the summer specifically for Culex mosquito control.  Residents are also advised to follow  Illinois Department of Public Health guidelines to reduce the risk of mosquito-borne diseases.