Springtime Fly Control

May 05, 2025

Hot weather means that fly season is coming across most of the state of Iowa. Flies are a pest and can be an economic penalty for producers, with flies causing stress and discomfort for livestock. We would like to start out insect control a month before we see the first fly.

Although flies have a short life cycle, they are active reproducers. Consider this: A female fly can lay upward of 400-500 eggs in a pile of manure during its life. In week zero, only two adult flies might be present in your pasture. However, due to warmer weather, available breeding grounds, and their reproductivity, by week eight, there could be more than 114 million flies of all ages present. Think about that and realize the importance of being proactive.

We can use several different options to control flies. Each has their benefits and downfalls, and each work to stop different insects in different ways.

Garlic: Garlic is a form of fly control that many have had good success with. It works by mixing it into mineral that the cattle are eating. Use at an inclusion rate of about 1 pound per bag of mineral. As the cattle eat the garlic, the odor is emitted through their skin and breath. This odor repels flies, ticks and mosquitoes. This is important, as ticks and mosquitoes are a major spreader of blood born pathogens.

Altosid IGR: This is a form of insect killer for Horn Flies. Horn Flies decrease milk production, cause blind quarters in udders, transmit mastitis, and reduce weight weaning in calves. IGR works by killing the fly larvae in the manure, breaking the reproduction cycle and reducing numbers.

Clarifly: Much like IGR, Clarifly works by breaking the reproductive cycle with the flies by targeting the larvae in the manure. The key difference is that Clarifly works on house, horn, face and stable flies. This product needs to be taken in constantly to work, so making sure cattle have adequate access to mineral is important. Providing enough mineral feeders for the head space or moving the feeders to higher traffic areas can all help with constant intake.

At the end of the day insect control is not a one size fits all for all operations and should be coordinated with spray, face mops, and other forms. What works for your neighbor might not work for you and some cattle prefer one product to another. On our farm we are using Blueprint mineral with Garlic and Clarifly to help control flies. We purchase the raw ingredients and mix them ourselves, but these products can also be special-ordered pre-mixed.

Contact us today and we can work on a solution for insect control on your livestock operation!