CRYSTAL LAKE – Large amounts of rainfall this summer have led to an increased number of mosquitoes to Crystal Lake, forcing the city to take additional measures to reduce the mosquito population.
Director of Public Works Michael Magnuson said the city historically sprays two to three times a year based on assessments of mosquitoes collected in traps placed around the city.
Sprays traditionally take place once the traps have reached a threshold of about 150 female mosquitoes.
“It’s something we budget for each year,” Magnuson said. “The frequency and the duration between the last spray and this spray is closer than we’ve done in the past, and that’s directly attributable to the repeated rainfalls we’ve had over the past few months.”
A citywide misting application was scheduled to take place overnight between Friday and Saturday as an additional measure to the city’s ongoing mosquito control program.
A rain date was set for the next night, between Saturday and Sunday.
The city implemented its mosquito management program in March 2001 based on recommendations by the Ad Hoc Mosquito Abatement Committee. The program focuses on larvicide treatment “designed to eliminate as many mosquitoes as possible before they develop into adults,” according to the city’s July newsletter.
The city entered into its current five-year contract with Clarke Environmental Mosquito Management Inc. in January 2016.
Magnuson said the annual contract with Clarke is $82,000, but the city budgets about $110,000 each year for mosquito reduction to compensate for additional measures.
Each additional spray costs about $12,000 when traps reach the threshold, he said.
“We’ve reached that level twice now, fairly quickly,” Magnuson said.
The Chicago-O’Hare region has received nearly 25 inches of rainfall since Jan. 1, which is about 7 inches more than the normal annual average, according to National Weather Service data.
Volunteer observers in Crystal Lake, who are not National Weather Service official observers, reported about 9 inches of rainfall in June and about 5.8 inches in May. Data for July is not yet available.