Mild winter could bring insect invasion, West Nile threat to Park Ridge, Niles
Lab Technician Ryan Mahoney, of Mount Prospect, squirts a buffer solution into a vile as he tests local mosquitoes for West Nile virus at the Northwest Mosquito Abatement District office June 15. | Ruthie Hauge~Sun-Times Media
Updated: August 20, 2012 1:54AM
They’re tiny, seemingly insignificant creatures — and they’re about to launch a summertime attack.
Mosquitoes are an inevitable part of a summer, but this year’s weather could mean greater numbers of the potentially disease-carrying variety.
Mike Szyska, director of the Northwest Mosquito Abatement District, said a dry spring has kept floodwater, or “nuisance,” mosquitoes at bay, but that same weather is also the perfect environment for nurturing Culex mosquitoes, the nocturnal pests that can carry West Nile virus.
“It’s Culex mosquitoes we start to get nervous about when we have excessively high temperatures and prolonged periods of no precipitation,” Szyska said.
A batch of Culex mosquitoes infected with West Nile virus was recently documented in Arlington Heights, he said.
Across the entire abatement district, which is supported by tax dollars and covers 242 square miles, including the city of Park Ridge, unincorpoarted Maine Township and half of Niles, “elevated numbers” of Culex mosquitoes have been identified, Szyska said.
The mild winter has also been favorable to Culex mosquitoes.
“Typically at this time of year the Culex are low in numbers because a lot don’t survive the winter,” Szyska said. “But because we had a mild winter, they did get a little of a head start. We are seeing higher numbers than we normally see.”
Culex mosquitoes are drawn to stagnant water, so any object holding water can potentially be a breeding ground (think flower pots, downspouts, bird feeders and retention ponds). These bloodsuckers come out largely at night and are less-aggressive biters than floodwater mosquitoes, which due to the lack of rain have not been as prevalent so far.
That could all change, though, when a period of heavy rain occurs, Szyska said.
Traps set up around the nine townships encompassed by the Abatement District, including one in Park Ridge, have been collecting Culex mosquitoes, Szyska said.
Crews from the Northwest Suburban Abatement District have been busy treating sewer-system catch basins across the area, as these are high producers of Culex mosquitoes due to stagnant water and trapped debris. Hundreds, even thousands, of Culex mosquitoes can be produced in a single catch basin, Szyska said.
“That’s a priority for us now to treat,” he added.
The abatement district also keeps an eye on mosquito larvae in Cook County Forest Preserve areas and treats retention ponds, ditches and — these days, at least — swimming pools sitting unused on foreclosed properties.
Neighborhood pesticide spraying from trucks normally takes place at night in areas where West Nile Virus has been detected, in areas with high numbers of Culex mosquitoes, or during a large floodwater mosquito outbreak, according to the abatement district’s website.
In an effort to reduce Culex infestation residents are advised to check their properties for containers with stagnant water, as well as clogged gutters and downspouts, which can produce thousands of mosquitoes.
Residents can report a standing-water problem by visiting the Northwest Mosquito Abatement District website, www.nwmadil.com.