The cities of Geneva, Batavia and St. Charles are all planning to spray for mosquitoes Wednesday evening after insects carrying the potentially fatal West Nile virus were discovered in local traps.
St. Charles plans to conduct conducting another citywide mosquito spray operation.
Geneva’s contractor, St. Charles-based Clarke Mosquito Control will spray a mosquito control application from dusk Wednesday, Aug. 19, to dawn on Thursday, Aug. 20.
Batavia plans to have Clarke conduct an adult mosquito truck spraying Wednesday evening too, though all plans could change depending on weather.
Batavia officials said positive West Nile results from the screening of mosquito samples continue to occur since treatment began in mid-July.
“Batavia does not spray mosquitoes on a routine schedule. Instead, for more than a decade, the City has used a science-based approach to determine when adult mosquito control is necessary,” the city said in a release. “Decisions are based on mosquito trap data, mosquito testing, and surveillance to help protect public health while using resources responsibly.”
Efforts to control the spread of West Nile include monitoring a network of mosquito traps, testing, treating standing water where mosquitoes breed and using targeted backpack sprayers in specific areas when needed, Batavia said.
West Nile virus can make people sick with a fever, and in some cases, it can cause serious problems like swelling in the brain or around the brain and spinal cord. The is spread by certain kinds of mosquitoes, especially Culex pipiens mosquitoes.
Clarke will use a synthetic treatment that is safe for humans and pets.
However, people with asthma and other respiratory conditions are advised to stay indoors with windows closed during the misting application and for one hour afterward, according to the release.
Otherwise, St. Charles officials said residents and their pets can be outside safely during the spray treatment. According to the city, the spray dissipates in under a half hour. The city said because the spray contains so few droplets per ounce in the air, it is safe for other insects, such as bees and butterflies.
The spray does not affect aquatic life, like in the nearby Fox River ecosystem, St. Charles officials said.
St. Charles has partnered with Clarke for more than 35 years.
Residents can report mosquito nuisances and standing water issues directly to Clarke via the company’s online portal at clarkeportal.com.
People can subscribe to receive advanced spraying notifications from Clarke when registering.
Geneva residents can subscribe to “community alerts” by selecting the “Notify Me” button on the City’s website, geneva.il.us.
Residents can receive advance notice of adult mosquito spraying by text or email by signing up through the Clarke Portal at clarkeportal.com.
People who contract the West Nile virus typically experience mild flu-like symptoms, especially fever, headache and body and joint aches, according to the Centers for Disease Control.
However, in less than 1% of cases, especially among the elderly, it can cause meningitis, brain-swelling, nerve damage and severe cognitive and motor issues, like seizures and paralysis.
In 2025 across the state, there were 150 total confirmed human cases of West Nile virus, with 10 deaths, according to the Illinois Department of Public Health.
The Kane County Health Department recommends avoiding mosquito bites by using repellents when going outdoors. Repellents containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide longer-lasting protection, according to its website, kanehealth.com.
Other tips include:
Wear long sleeves and pants from dusk through dawn when many mosquitoes are most active.Install or repair screens on windows and doors. If you have it, use your air conditioning.Reduce the number of mosquitoes around your home by emptying standing water from containers such as flowerpots, gutters, buckets, pool covers, pet water dishes, discarded tires and birdbaths.