Understanding insect life cycles and the conditions that encourage or discourage populations to proliferate guides management decisions that can help you beat the bugs, reduce the risk of disease transmission, and keep your horse comfortable during peak pest season. | iStock

Practicing smart insect control tactics year-round can help you keep populations under control

Biting insects can cause unsightly welts and itchy bumps. They can also transmit pathogens that cause diseases such as West Nile virus and pigeon fever. Unfortunately, however, these pests are simply part of barn life. While it’s impossible to eliminate every irksome insect, you can take a variety of steps to minimize their numbers.

“Insects are ectotherms, which means they develop faster the more the weather warms. Flies generally have very fast life cycles,” says Erika T. Machtinger, PhD, an assistant professor of entomology at Pennsylvania State University, in State College. “This means that if fly populations are not controlled early, they can get out of hand quickly and can be near impossible to control.”

For many fly species found around the barn, it only takes seven to 10 warm days for their eggs to transition through three larval stages to become pupae and hatch into adult flies, explains Sonja L. Swiger, PhD, a professor and veterinary/medical extension entomologist at Texas A&M AgriLife Extension, in College Station. Colder temperatures slow the process to 10 to 14 days, which is still enough time for a population explosion, especially given that one adult female stable fly can lay up to 600 eggs, she adds.

Insect species thrive in different conditions. For example, mosquitoes and horse- and deerflies develop in water. “Filth flies” such as blowflies or houseflies thrive in rotting materials like garbage and decomposing organic matter such as hay, manure, uncovered or dropped feed, and grass ­clippings.

“Filth flies are decomposers, or at least the larvae are,” explains Swiger. “The larvae are one of the few organisms that can and will inhabit manure and consume it.”

Flies are very good at finding places to breed and lay eggs, and some can fly 2 to 8 miles, so if another farm down the road isn’t as clean as yours—think garbage storage or disposal—you might get flies coming in from that area, she added.

Understanding insect life cycles and the conditions that encourage or discourage populations to proliferate guides management decisions that can help you beat the bugs, reduce the risk of disease transmission, and keep your horse comfortable during peak pest season