HINSDALE, Ill. — On a quiet residential street near downtown Hinsdale earlier this week, a white Toyota Prius pulled over and two men in khaki shorts, crisp polo shirts and black helmets climbed out.
The pair unfastened hybrid mountain bikes from a rack on the car, then pedaled up and down the suburban roads on a mission few residents may have realized has been in progress all summer — especially now, as higher temperatures trigger a rise in mosquito populations.
Meet the modern-day mosquito hunter, eager to kill but in environmentally friendly ways, including the use of all-natural chemicals, high-efficiency vehicles and even live fish that chomp up larvae the way Mother Nature intended.
“People have been requesting this,” said George Balis, regional manager and entomologist for Clarke, an environmental services company based in St. Charles, Ill.
This year, 13 Chicago-area municipalities have hired the company to deploy a new eco-friendly strategy in fighting the pesky insects. Called the EarthRight program, it replaces trucks and fogging with bike-riding workers armed with all-natural tablets that are slightly bigger than a quarter and designed to kill larvae.
“We’re trying to do things better, smarter and more environmentally minded,” said Dave Gorman, assistant director of public works for Lombard, Ill., one of the communities that has hired Clarke.
The efforts are in full swing as mosquito crews report an uptick in the number of mosquitoes, mostly because of the recent warm weather.
The North Shore Mosquito Abatement District trapped 3,300 mosquitoes in the week that ended Aug. 15. Less than a week later, the traps registered 5,500 mosquitoes, spokesman Dave Zazra said.
Officials in Chicago’s northwest suburbs also report increases in mosquito populations over the last two weeks.
At the same time, the overall cooler and wetter summer has kept reports of West Nile virus down. This year, 3 percent of mosquito samples tested positive for the virus, compared with 9.7 percent in 2013 and 25.6 percent in 2012, said Melaney Arnold, spokeswoman for the Illinois Department of Public Health.
Clarke, which handles mosquito control in three counties, agreed to use the environmentally friendly approach in 13 communities this year after experimenting with various strategies since 2005.
Through trial and error, the company ruled out using motor scooters instead of trucks and embraced other tactics such as developing two new mosquito control materials that are safe to use around organic gardens and farms.
Today Clarke hires bike crews to ride through communities, dropping tablets of a larvicide known as Natular into hundreds of storm sewer catch basins. The tablets kill mosquito eggs in the standing water and remain effective for up to 30 days, Balis said.
Crews tackle larger areas with backpack blowers designed to spread a granular version of Natular. The company also uses smaller trucks with electric sprayers — not gas-powered, so as to reduce the carbon footprint — to spread a material called Merus, which kills adult mosquitoes.
The effort costs the same as traditional, truck-driven mosquito control methods but is 15 percent more effective, Balis said.
“It really takes what we’ve had in mosquito control and moves it a step forward,” said Balis, adding that crews have grown accustomed to puzzled looks and questions from residents.
“The first thing people say is, ‘What’s going on?’” he said. “It’s become a better public outreach.”
The North Shore Mosquito Abatement District, which handles mosquito control for 13 communities north of Chicago, has used its own crews to drop Natular tablets in 50,000 catch basins each season for the past two years.
The district also uses a mosquito-eating fish called gambusia to keep mosquito eggs from hatching at 20 sites in its coverage area where the minnow-sized fish can’t escape into larger bodies of water.
At the end of the season, workers come back to collect the fish, spokesman Zazra said.
“Best practice is to always be as environmentally friendly as possible,” he said. “Everyone becomes more environmentally aware.”
In Hinsdale, village officials have been pleased with preliminary numbers that indicate the mosquito population has not increased since last year, before their eco-friendly strategy began, said George Franco, village director of public services.
The presence of bikers dropping tablets into the catch basins has prompted at least one concerned call from a village resident, who worried that the activity was illegal or drug-related. But once Franco explained the new program, the caller was supportive, he said.
“I’ve had to explain to them that we’ve had to change,” Franco said. “They were actually receptive to that and enjoying that we’re becoming a greener community.”
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