Many Iowans are finding it hard to enjoy the great outdoors this summer because of a boom in the mosquito population. Iowa State University entomology professor Ken Holscher says the best defense against the pest is a repellent containing DEET.

“I know there’s been some concern by some people over the years about whether or not using (DEET) can be harmful to you, so there are some newer products on the market,” Holscher said. “But they’re not any better than DEET and they might not be any safer.” Some bug repellents contain high concentrations of DEET, but Holscher recommends using products with lower concentrations and reapplying throughout the day. He also advises people to use roll-on or squeeze-on applicators rather than aerosol sprays.

“I just think it makes better sense to apply those materials to the areas of the skin where it’s needed rather than just dousing yourself down with a spray can of that stuff,” Holscher said. Other tips include wearing pants and long-sleeve shirts and avoiding the outdoors during dawn and dusk when mosquitoes are more active. Researchers at the ISU Medical Entomology Lab have seen big mosquito populations at trap sites around the state.

The record rainfall in June is the major factor, but Holscher says areas of the state that received torrential downpours may not necessarily have more mosquitoes. “A five inch rain in one hour isn’t going produce more mosquitoes than five one-inch rains spaced over the course of a month,” Holscher explained.

“Mosquitoes develop in standing water and when you get a torrential rain, a lot of that flows off and stands in areas where it’s never stood before and it’s not going to produce many mosquitoes.” There is a bit of good news – Holscher says the species of mosquitoes in Iowa right now are not linked to the transmission of West Nile or other viruses.