Horn Fly Control: The 4 Steps To Get Rid of Horn Flies

Sanitising your barn and its surroundings by removing manure, wet hay, and animal bedding is necessary for effective horn fly control.

Apply Flex 10-10 insecticide using a combination of pour-on and spray methods to treat the affected area.

Discover effective methods and products to eradicate horn flies from your property by reading this information-filled article below!


Step 1: How To Identify the Horn Fly

Horn Fly Control
Picture of the Horn Fly
  • Horn flies, smaller at 4 mm long, have a dark, brown-grey to black colouration, resembling stable flies and house flies.
  • Adult horn flies are characterised by two dark stripes on the thorax and a few spots on the top of the abdomen.
  • Horn flies possess spear-like mouthparts located beneath their heads, enabling them to feed on animals. Both genders possess these mouthparts.
  • The pest has downward-pointing, brownish-red antennae on its head.
  • Yellow to white larvae, approximately 7 mm in length. During their pupae stage, they appear as a 3-4 mm-long dull red-brown colour.
  • Broad wings overlap in a V shape.


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Step 2: How To Inspect For Horn Flies

Horn flies gather in clusters on cows’ shoulders, backs, and sides, unlike other types of flies. During hot or rainy weather, they relocate to the stomach area or undersides of cattle. Horn flies rest with their heads pointed downward on animals.

Cattle are only used by them as a breeding ground for their eggs in wet manure. The horn fly is attracted to the waste secreted by infested animals. White maggots will appear in the waste and feed until they are ready to move onto the animal.

Horn flies are commonly found on cattle in open pastures on hot days. Horses and feedlot cattle can sometimes be used as a meal for certain animals. Fresh or moist manure is a prime breeding ground for horn flies.


Step 3: How to Carry Out Horn Fly Control

  • Eliminate Breeding Sites:

Horn flies are drawn to places with manure and decaying organic material, like hay and animal bedding, because they offer ideal conditions for breeding.

Cattle owners face challenges due to the significant daily waste produced by these animals.

Regular waste and moist hay handling is essential for all cattle herds, regardless of size. It should be done consistently, preferably once a week.

Remove organic matter from barns, fences, water troughs, stalls, paddocks, fields, pastures, and underfeed bunks.

Move manure piles away from barns and animal areas.

  • Apply a Residual Insecticide:

Horn flies primarily reside on cattle throughout their lifespan, excluding the larvae and pupae stages. To effectively treat the animal, it is recommended to use a concentrated insecticide that can be applied as a pour-on.

Flex 10-10 is a pest control service. Insecticide is a potent pyrethroid-based concentrate that effectively eliminates pests, such as horn flies, with its fast action and long-lasting effects.

To control pests on dairy and beef cattle, as well as horses, dilute 4 teaspoons of Flex 10-10 Insecticide in a gallon of water (1:200 ratio). This will create a ready-to-use product with 0.05% permethrin.

To combat severe horn fly infestations, dilute 8 teaspoons of the product in a gallon of water (1:100 ratio). This creates a ready-to-use product containing 0.1% permethrin, which is effective for pest control.

Thoroughly wet the hair, especially in areas where pests are present, such as the topline, underline, flanks, and withers.

Apply treatment every 5-12 days, unless the insect presence is minimal. Increase frequency if the horn flies population is high.

For ongoing control and prevention of horn flies, it is recommended to use insecticidal sprays with a long-lasting residual, such as Flex 10-10 Insecticide.

This product is suitable for use in animal quarters, dairy and beef barns, and other specified livestock or animal housing areas, as well as residential lawns.

Use the Tomahawk TMD14 backpack fogger to apply Flex 10-10 insecticide effectively.

Combine 64 fluid ounces of Flex 10-10 insecticide with 55 gallons of water to create a solution containing 0.09% permethrin and 0.09% PBO.

To control horn flies, dilute 1 gallon of product in 55 gallons of water. This will create a solution with 0.18% permethrin and 0.18% piperonyl butoxide.

Evacuate animals and people from the treatment area and ensure proper ventilation before allowing re-entry.

To prepare the sprayer, fill the tank halfway with water. Next, add the specified amount of Flex 10-10 insecticides. Finally, fill the remaining half of the tank with water. Shake the tank with the lid closed for even agitation.

Apply pesticide to both the upper and lower surfaces of foliage leaves, as well as all areas inside barns, ensuring comprehensive coverage.

To prevent contamination from spray, it is important to close milk tank lids and remove milking utensils.


Where Can the Horn Fly Control Products Be Purchased?


Read also: 4 Steps For Effective Caddisfly Control


Step 4: How To Prevent Horn Flies?

  • Regularly clean and remove manure, uneaten feed, and damp hay from your barn and pastures to deter horn fly breeding.
  • Move manure and compost piles away from barns and animal areas to prevent pests.
  • Use an approved feed additive for cattle to prevent horn fly larvae from developing in their waste.
  • Rotate between organophosates and pyrethroid products annually to avoid horn flies developing resistance to these chemicals. Use Flex 10-10 every 90 days for application sites and every 5 to 12 days as a pour-on application when insect population is not too high.


Read also: What are the 4 Steps To Get Rid of Adelgid Control?


Watch an Explanatory Video on Effective Horn Fly Control



With the arrival of warm weather, be prepared for the appearance of irritating horn flies. Small nuisance flies can cause various issues for your cattle, despite their limited mobility and size.

To prevent horn flies from bothering your cattle, animals, and property, it is recommended to regularly use integrated pest management techniques and apply Flex 10-10 insecticide every 90 days to the designated area.

Thank you for your attention!

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