Changing weather fuels tick populations
Published 12:00 am Saturday, May 23, 2026
Missouri’s changing weather patterns are creating more favorable conditions for ticks, increasing concerns for the agricultural community and anyone who spends time in fields, forests or backyards.
University of Missouri Extension State Climatologist Zachary Leasor said warmer winters, earlier springs and periods of high humidity allow ticks to survive in greater numbers, become active earlier in the year and remain active later into fall.
Traditionally, Missouri’s cold winters helped reduce tick populations. That natural control is weakening as winters become more mild. The state’s average wintertime temperature has been warmer than average eight of the last 10 years.
Blacklegged ticks, lone star ticks and American dog ticks — all common in Missouri — can survive winter conditions by sheltering under leaf litter, crop residue and snow cover, MU Extension urban entomologist Emily Althoff said.
When winter temperatures rise above freezing, ticks can become active even in midwinter.
“These shifts are contributing to increased tick encounters and a growing risk of tick-borne diseases, including alpha-gal syndrome, across the state,” Althoff said.
With milder temperatures, ticks may begin actively seeking hosts earlier than in the past, and activity can extend well into late fall during mild years.
Ticks are not only a human health issue.
Heavy tick infestations can reduce weight gain in cattle, transmit diseases and increase veterinary costs. Livestock and working dogs should remain on veterinarian-recommended tick prevention to reduce exposure and keep ticks from being carried into equipment, vehicles or homes.
To help limit tick habitat, manage vegetation by mowing field edges, trimming fencerows and reducing brush near barns and work areas.
Experts recommend wearing long sleeves, long pants and boots when working outdoors. Tuck pants into socks or boots and choose light-colored clothing to make ticks easier to spot. Environmental Protection Agency-approved insect repellents containing DEET, picaridin or permethrin-treated clothing add an important layer of protection.
Perform tick checks at the end of each workday, and promptly remove attached ticks.
Pesticide poisoning
Pesticide poisoning can be confused with common illnesses like the flu.
“Pesticides include chemicals used to control weeds (herbicides), insects (insecticides), rodents (rodenticides) or fungi (fungicides). If the word ends in ‘ide,’ it is likely a pesticide that can poison you if used incorrectly,” said Rusty Lee, who teaches pesticide courses for MU Extension.
Most pesticides pose little risk when used according to label instructions. But Lee said farmers and others who handle pesticides this spring should consider that they may be suffering from pesticide poisoning if they become ill after usage.
The farming community is at the most risk for exposure, but home gardeners also face risk, Lee said. Residue left on lawns, plants, soil or spray equipment can present risks.
Immediate pesticide poisoning symptoms include:
• Neurological — Headaches, dizziness, weakness, fatigue, muscle twitching, trembling and mental confusion.
• Gastrointestinal — Nausea, vomiting, abdominal cramps and diarrhea.
• Respiratory — Difficulty breathing, cough, chest discomfort and excessive secretions from the mouth and nose.
• Dermal/Ocular — Skin irritation, rashes, excessive sweating and eye irritation.
In case of injury, take the label on the pesticide jug to the emergency room. The label will help emergency personnel determine treatment.
The Missouri Poison Control Center can be reached at 800-222-1222 and online at https://MissouriPoisonCenter.org.
