Fly season is in full swing, and a Purdue Extension entomologist says insect control is essential as these pests can lead to disease and decreased growth rates in livestock.
Insects can be problematic in both pasture and confinement settings, said Ralph Williams, professor of entomology at Purdue. Cattle and poultry are especially vulnerable.
"Sometimes we forget that when we are irritated by mosquitoes, we can go inside," he said. "Livestock are out there all the time, so insect pests are more than just a nuisance."
Pastured cattle fight face flies, which can transmit pink eye, and horn flies, a biting fly that results in reduced weight gain and feed efficiency — and ultimately economic loss.
Within confinement operations, stable flies are a source of a direct irritation to cattle and also can cause financial loss.
"In confinement, it's important to reduce breeding sites for flies by focusing on manure removal and waste management," Williams said.
"In pasture situations, insecticide ear tags provide one of the best methods of fly control. Ear tags contain various chemical compounds and are typically hung in both of the animal's ears throughout the fly season."
According to Williams, the pyrethroid tags are the best solution for face flies, but horn flies are resistant to its effects. A recent product, abamectin, and Warrior, a formulation with two organophosphate-based insecticides, are effective for both species.
With the wet spring, other insects that thrive in excess water, such as biting midges and mosquitoes, could also be problematic this year. Midges can spread Epizootic Hemorrhagic Disease in ruminants, and mosquitoes carry diseases for multiple animal species.
Large animals are not the only species affected by insect pests. Poultry confinement operations battle flies year-round as houseflies breed in fresh accumulated waste.
"In addition to being an issue for the farmer, house flies can also become a nuisance pest for operations in non-farming communities," Williams said. "To keep in line with regulations, poultry producers really have to keep on top of pest control."
For all species, Williams said that facility sanitation is the first step to controlling flies and other insects.