In 1931, the Highland Park Mosquito Abatement District was formed to protect the health and comfort of area residents. At its start, the district included the towns of Bannockburn, Deerfield, Highland Park, and Highwood, and later, was expanded to include Riverwoods. In 1987, the District’s name was changed to the Southlake Mosquito Abatement District (SLMAD), to reflect its regional stature.

Under state law, SLMAD is administered by a five-member Board of Trustees, comprised of residents of the district, who are appointed by the County Board to serve without compensation. Operations are financed by taxes levied within the district. SLMAD contracts with Clarke Environmental Mosquito Management, Inc. to control mosquito growth and infestation.

While many residents think of the nuisance factor when it comes to these pests, mosquito control is also a public health issue. There are 38 species of mosquitoes in Lake County, with the potential to carry St. Louis encephalitis, which affects older and disabled people, and LaCrosse encephalitis, which primarily affects children.

Control is linked to the life cycle of the mosquito. Most species overwinter as eggs and breed in stagnant water with a high organic content, which nourishes the larvae. Thus, ponds, catch basins and floodplains are typical sites for larval control. Adult mosquitoes like to rest in tall grass and shrubbery. Thus, such "harborage" areas are targeted for spraying.

SLMAD uses aerial and ground surveying and mapping to identify larval development sites and categorizes them depending on size, habitat, and location. A data base is maintained, showing the numbers of larvae present for the various sites. This information determines which management approach is appropriate in a specified area.

The first line of attack is larval control - treating areas where mosquitoes are breeding. In the SLMAD, treatment is most often accomplished with altocid, a hormone that prevents larvae from becoming adults, and Bacillus thruingiensis var. israelensis (Bti), a bacteria that attacks only black flies and mosquitoes. Altocid is used by catch basins in pellet form, while Bti is applied with backpack sprayers and helicopters.

To reduce adult populations, "on the wing" adulticiding is performed. Adult control consists of ULV (ultra low volume) misting of residential and harborage areas with permethrin, a synthetic substance based on a naturally-occurring insecticide. Permethrin is 80 percent degradable within 12 hours. All products are U.S.E.P.A.-approved for use in residential areas, and application is performed by licensed personnel of the Illinois Department of Agriculture.

Spraying is done from April through September when broods migrate, 30 or more females are found in a trap, or when residents register complaints (although complaints will not trigger spraying, but intensify surveillance in the area). Spray procedures include the following:

• Weather must be cooperative - no rain or winds in excess of 15 mph;
• Residents who have requested notification are contacted;
• Dosage and quality control analysis is performed.

Spraying is done on an as-needed basis. The district is separated into 17 sections, including six within Highland Park. Each section corresponds to a trap used for surveillance. This surveillance helps determine the distribution and density of mosquitoes throughout the district. Data from these traps and use of a computerized Brood Prediction Model allow the SLMAD to limit spraying to the section (or sections) that need it.

Contact Information
For more information about mosquito control in the Highland Park area, call the District’s Mosquito Hotline at (800) 942-2555. This number is also the one to call if you wish to be notified of spraying, or to request that your property be excluded from spraying.