Rain-drenched spring brings rise in mosquitoes in McHenry County
A wet start to the summer season has McHenry County all abuzz – with pesky mosquitoes.
Unlike last year, when drought conditions served as a breeding ground for West Nile virus-carrying mosquitoes, a rain-drenched spring and early summer has meant more floodwater mosquitoes, commonly referred to as nuisance mosquitoes.
That includes as much as 6 inches of rain that fell in Cary earlier this week, and the rest of the county receiving at least a few inches.
“It’s been the complete opposite to last year,” said George Balis, entomologist at Roselle-based Clarke. “There’s a considerable difference this year because of the rain, and residents will see a lot more floodwater mosquitoes than they have in previous years.”
Culex mosquitoes commonly carry the West Nile virus and thrive in hot, dry weather. The virus is most commonly spread through mosquitoes and birds.
The McHenry County Department of Health reported its first positive test for West Nile virus this week from a trap in Harvard. The health department had tested 128 mosquito batches as of June 20. Two other counties have reported positive batches this year.
There were six human cases of the virus reported in 2012 in the county. Two birds have been submitted and tested this year with negative results.
In 2012, 55 counties had mosquito batches, birds or humans test positive for West Nile, according to the Illinois Department of Public Health. There was also the second highest number of West Nile virus human cases on record with 290 residents and 12 deaths.
Because three out of the four life cycles of mosquitoes occur near water, most control efforts focus around storm drains, catch basins, wetland and other bodies of water throughout the county.
The wet weather this season has created a breeding ground for the blood-sucking pests.
The city of Crystal Lake has budgeted $130,000 for its mosquito abatement program, including $82,000 specifically for monitoring and limiting the adult population. The larvacide treatments are designed to eliminate as many mosquitoes as possible before they develop into adults.
Six zones with light traps to monitor more than 3,000 catch basins are tested weekly for females, and if more than 150 females are found on two consecutive readings, spraying is used throughout the community.
Two virus-isolation traps also are set up to collect mosquitoes known to transmit the West Nile virus. Those mosquitoes are collected and sent to an independent laboratory for testing.
“Last year was weird because of the drought,” Deputy City Manager George Koczwara said. “Cooler weather has kept the mosquitoes down thus far, but anything can happen with this rain and warmer temperatures.”
The village of Huntley budgeted about $80,000 for mosquito abatement this year, which typically includes six adult sprayings throughout the season. Officials also use larvacide tablets to place in catch basins.
“We target when they are expected to hatch,” said Jim Schwartz, public works director. “This helps keep the adult population under control.”
The city of Woodstock again has set aside $28,000 to control the mosquito population. That includes larvacide treatments once a month and aerial spraying as needed.
“The worst year we have had, we maybe sprayed three times,” said Jim VanLanduyt, interim public works director. “We have gone years without having to use them. We’re not sure what to expect this year.”
<SUBHEAD>Ticks also a problem<SUBHEAD>
In addition to mosquitoes, tick season also heats up during the summer months.
Ticks live in and near wooded areas, tall grass and brush.
The American dog tick and Lone Star tick can spread disease, but the blacklegged or deer tick is the most common disease carrier, especially of Lyme disease, in Illinois and the surrounding states.
In 2012, 39 human cases of Lyme disease were reported in the county, along with three cases of other tick-related illnesses, including erlichiosis and Rocky Mountain spotted fever. The county had 19 cases in 2011.
Six cases of Lyme disease and one case of Rocky Mountain spotted fever have been reported in the county this year, according to the county health department.
Ticks are unable to jump or fly, so they wait in ankle-high grass and other low areas for humans, dogs and other animals to pass by.
There are some products that can be put down on lawns to kill ticks, said Balis, but for the most part, there is no way to avoid them, only check for them.
“People are going to go beyond those treated areas,” he said. “The key is to look at what’s out there, check your children and pets after they’ve been out, or wear repellents.”
To reduce the risk of tick bites, avoid wooded areas or places with tall grass or weeds and leaf litter; apply insect repellent with DEET; wear light-colored clothing that makes ticks easily visible; walk in the center of trails and stay on well-traveled paths; and check family members and pets thoroughly after they have been outside.
According to the Illinois Department of Public Health, the best way to prevent West Nile virus or any other mosquito-borne illness is to reduce the number of mosquitoes around the home and take precautions to avoid mosquito bites using the three “R’s.”
• REDUCE exposure by avoiding the outdoors when mosquitoes are most active, especially between dusk and dawn. Make sure doors and windows have tight-fitting screens, and repair or replace screens that have tears or other openings. Keep doors and windows shut, especially at night. That includes eliminating all sources of standing water where mosquitoes can breed, such as water in birdbaths, ponds, flowerpots, wading pools, old tires and any other receptacles.
• REPEL mosquitoes when outdoors by wearing shoes and socks, long pants and a long-sleeved shirt. Apply insect repellent that contains DEET, picaridin, oil of lemon eucalyptus or IR3535. Consult a physician before using repellents on infants.
• REPORT an overabundance of mosquitoes in communities where there are organized mosquito control programs. Contact local municipal government to report areas of stagnant water in roadside ditches, flooded yards and similar locations that may produce mosquitoes.
Source: McHenry County Department of Health