While heavy rainfall on top of significant snowmelt have created prime breeding grounds for mosquitoes, cooler weather is slowing the development of mosquito larvae and the bugs aren't expected to be too numerous this Memorial Day. | File photo
Updated: June 27, 2014 6:16AM
While significant snow melt and heavy rains have created prime breeding grounds for mosquitoes, they’re not expected to be a huge nuisance this Memorial Day.
“We’re seeing quite a bit of breeding activity,” Douglas Wright, general manager of the South Cook County Mosquito Abatement District, said Friday.
However, cooler temperatures are helping to slow the development of eggs into adult mosquitoes, he said.
The district covers 340 square miles of south and southwest Cook County, and its crews have been treating areas of standing water, including stormwater retention ponds and puddles along forest preserve walking trails, Wright said.
He said if there are mosquito larvae in standing water, the district applies a bacterial spray that targets only mosquitoes, then reinspects treated areas about 10 days later.
While some mosquito larvae have reached maturity, the bugs that are flying around won’t be as numerous and they won’t include the Culex mosquito that can transmit the West Nile virus, according to Wright.
Culex mosquitoes are “more active when it’s real stagnant and hot,” and the “mosquitoes we are dealing with now are more of a nuisance and not known to carry the West Nile virus,” he said.
While heavy rains can create mosquito breeding areas in ditches and low-lying areas, storms also help flush out larvae clustered in storm drains, said Joseph Conlon, technical adviser to the American Mosquito Control Association. Some Southland communities saw as much as two inches of rain during last week’s downpours.
While the Southland might be getting a break from mosquitoes right now, Wright and Conlon noted that cooler temperatures merely delay their arrival. During warmer weather, it might take six to seven days for larvae to reach maturity, and cooler weather might stretch that to 10 or 12 days, Conlon said.
They said that homeowners can take some simple steps to reduce or eliminate breeding areas on their property.
Cleaning gutters and downspouts will keep gutters free of standing water, and homeowners are advised to regularly replace water in bird baths and empty water that’s collected in dishes underneath potted plants and flowers. Also, they suggest draining rainwater that’s collected on pool covers.
“Those breed mosquito larvae like crazy,” Conlon said.
Wright said the mosquito abatement district will treat stagnant water in pools at homes that have been abandoned or foreclosed on, and there has been a “high increase in those numbers because of the economy.”