• A reoccurrence of flies, oftentimes brought on by seasonal weather
• An abundance of flies from not initially treating for fly control
• Ear tags wearing out, especially in locations with longer fly seasons

Luckily, protecting your operation from the threat of pests and the damage they can cause doesn’t have to be difficult. Creating and implementing a mid-season strategy may help defend against potentially damaging pests.

Know your flies

Fly control is essential since the fly species associated with cattle can be found wherever cattle are located. It’s best to learn and know how the four major fly species can affect your cattle’s productivity.

Face fly

The face fly can typically be found clustering around the animal’s eyes, mouth and nose. Face flies are usually seen on cattle kept on pasture. They spread bacteria that cause pinkeye, resulting in painful eye lesions causing the animal to avoid sunlight, resulting in reduced weight gain.

Horn fly

Like face flies, horn flies are primarily found on pasture cattle. These are small, dark gray flies with stiff, needle-like mouthparts. They bite cattle to feed on their blood and are responsible for the spread of mastitis caused by Staphylococcus aureus and also can spread other disease-causing bacteria.

House fly

House flies don’t bite and may seem harmless, but they’re known to transmit at least 65 disease-causing organisms. They are a nuisance to your animals, you, your family, your workers and even your neighbors.

Stable fly

Stable flies feed on blood, and their painful bites are known to cause reduced weight gain and milk production. In fact, studies have estimated that stable fly infestations of individual herds cause median annual-per-animal production losses of 306 pounds of milk for dairy cows.

Protecting your operation mid-season

When considering mid-season fly control, look for options that match the type of flies or fly pressure in your area. Key questions include:

• Where is the insect found? On the animal, in the facility or in the area around the farm?
• How much of an issue is the fly pressure, meaning how quickly do you need to address it?
• What are your farm’s capabilities, such as the practicality of gathering animals for treatment, employees and time available, and your budget?

Next, identify fly control products effective against the species of flies you have. And be sure to pick a product that begins to work quickly, one that starts to work within a matter of days rather than weeks.

Take action now

Flies may seem like just a nuisance, but it’s important to understand the negative impact they have on your operation. When you have a fly problem, your animals can experience a decrease in milk production or weight gain, and are at a higher risk for the spread of disease.

The foundation for any comprehensive fly control program is sanitation to limit flies’ opportunity to reproduce on your operation. Additionally, use at least one other method of control – such as fly tags, dust bags, back rubs, sprays, pour-ons or baits – to target adult flies already on your facility or that migrate from or breed in other sources.

Places in the South tend to have longer fly seasons, so ear tags may start wearing out. If this is the case for your operation, you may want to supplement the ear tags with an additional control option, such as pour-ons, dusts or on-animal sprays. Insecticide pour-ons and dusts are ready-to-use, and dusts can be applied with a hanging dust bag or shaker can. Sprays can be used on the animal or in and around premises.

Remember to rotate

To maintain effectiveness, it’s important to rotate your pest control to help bolster your defenses. This helps minimize the development of resistance to your insect control strategy. Consider rotating to a product that uses a different mode of action (MOA).

Available MOAs include:

• Pyrethroids – active ingredients such as cyfluthrin, cypermethrin, deltamethrin, permethrin
• Organophosphates – active ingredients such as diazinon, coumaphos, tetrachlorvinphos
• Neonicotinoids – active ingredients such as imidacloprid and dinotefuran (only found in baits)

Preventing pests’ repeated exposure to any one insecticide MOA will slow the development of resistance in pest populations. Use what fits your management style best, but be sure to keep a control option active.

Safety first

As a final point, always exercise caution and read the label for the products being used. Also, ensure that the employees applying the products are trained to understand the proper use of each product and the appropriate equipment needed.  

Dr. Doug Ross is a senior technical services entomologist with Bayer Animal Health.

References omitted but are available upon request. Click here to email an editor.

PHOTO: Flies are more than a nuisance for cattle operations; they also have a negative impact on cattle gain and herd health. Staff photo.