By Andi Anderson
As summer transitions into fall, many livestock producers may pay less attention to fly management. However, late-season fly control remains an important part of maintaining cattle health and farm profitability. Fly populations can increase rapidly during this period because many products applied earlier in the season begin to lose their effectiveness.
According to Dr. Michelle Arnold, DVM, Ruminant Extension Veterinarian, UKVDL, continued fly management is essential to reduce livestock stress, improve production, and limit the development of insecticide resistance. Effective control during the fall also helps reduce the number of flies that survive the winter and return the following season.
Two of the most common pasture pests are horn flies and face flies. Horn flies spend most of their lives on cattle, feeding on blood multiple times each day. Their constant feeding causes irritation, blood loss, and reduced grazing activity. As a result, cattle may experience lower weight gains and reduced milk production. Economic losses often become significant when horn fly populations exceed recommended levels.
Face flies create different challenges. Instead of feeding on blood, they feed on tears and eye secretions. Their activity around the eyes can irritate cattle and contribute to the spread of pinkeye. Because face flies spend only a short time on animals and frequently move between herds, they can be more difficult to control than horn flies.
Understanding insecticides is equally important. Fly control products work through different modes of action. Repeated use of the same type of insecticide can allow some flies to survive and develop resistance. Over time, resistant flies can pass these traits to future generations, reducing the effectiveness of control programs.
To slow resistance development, producers are encouraged to rotate insecticides with different modes of action from year to year. Using a variety of control methods can further improve effectiveness and extend the useful life of available products.
Several fly control options are available, including ear tags, sprays, pour-on treatments, dust bags, back rubbers, and feed-through products. Fly tags are widely used because they provide reliable horn fly control. However, many tags lose effectiveness by late summer or early fall, making additional treatments necessary.
Pour-on products and sprays can provide short-term protection and are often used when fly pressure increases after tags become less effective. For face flies, products that regularly place insecticide around the head and face generally provide the best control.
Non-chemical methods can also help reduce fly numbers. Fly traps, sticky traps, and proper pasture management may support overall fly control efforts. Some producers also use feed-through insecticides that target fly larvae developing in fresh manure. These products can reduce future fly populations when used consistently throughout the season.
Late-season management plays a critical role in maintaining cattle comfort and productivity. Fly populations that survive during the fall can contribute to greater pest pressure the following year. Continuing control measures through the end of fly season helps reduce these risks.
Producers should always follow product label directions regarding application rates, timing, safety precautions, and withdrawal periods. Combining multiple management approaches while rotating insecticide types can provide the best results.
By maintaining a strong fly control program through fall, cattle producers can protect animal health, reduce disease transmission, improve production performance, and help preserve the effectiveness of insecticides for future seasons.
FAQ 1: Why is late-season fly control important for cattle?
Late-season fly control helps protect cattle from diseases, stress, weight loss, and reduced milk production. It also reduces the number of flies that survive through winter and helps prevent insecticide resistance from developing.
FAQ 2: What are the main differences between horn flies and face flies?
Horn flies stay on cattle most of the time and feed on blood, causing irritation and production losses. Face flies feed on tears and eye secretions, making them major carriers of pinkeye and more difficult to control because they spend less time on the animal.
FAQ 3: Why should cattle producers rotate insecticides?
Using the same insecticide repeatedly can allow flies to develop resistance. Rotating products with different modes of action helps maintain product effectiveness and improves long-term fly control.
Photo Credit: gettyimages-ahavelaar
Categories: Ohio, Livestock