Significant growth and production losses can occur in cattle from the annoyance of flies – cattle spend time swishing tails, flipping heads and twitching skin, using energy and taking away valuable grazing time. However, the herd will still be susceptible to biting flies from neighboring properties. They have been known to feed on horses, dogs, swine and sometimes humans. Extension   /   Horn flies look like houseflies and stable flies, but horn flies are slightly smaller. During extremely hot weather or rains, they will move lower sides and underside of the animal. These products contain insecticides that pass through the animal’s digestive system and remain in the manure where horn fly maggots develop. Fly traps. Horn flies are those bugs that stay on cattle all the time, usually bunched up in a mass along the withers and down the back to the tailhead. Conditions that fast drying of manure, along with activities of dung beetles also can provide some natural control. Research   /   Research shows that a calf infested with more than 200 horn flies will weigh 15 to 50 pounds less at weaning. However, they do have piercing mouthparts like that of the stable fly. The females deposit eggs in fresh manure. Horn flies can affect performance and rate of gain as cattle spend more time under trees or in water looking for relief. Fire ant control is effective when horn fly populations are small, but as they increase in the summer, the impact is not as apparent. One disadvantage of feed additives is that it is difficult to regulate each cow’s feed intake. Horn flies are the ones we see on cattle’s backs in summer. A walk-though fly trap. This is a great device to get rid of horn flies which are usually found at the backs and sides of your animals. It can often feel like an uphill climb with no rest in sight. Horn flies puncture the skin to suck blood and usually are found on parts of the cow’s body not easily reached by the head or tail. This delay minimizes the chance for the flies to develop early-season resistance to the insecticide in the tag. Horn flies rest on an animal between feedings; stable flies remain on the animal only while feeding. Specific steps can be taken to manage resistance, including: 1) rotation of insecticides in ear tags with different modes of action, 2) withholding tagging until horn fly numbers reach 200 per animal, 3) only treating cattle in the growth mode, 4) use of alternative insecticides and application methods late in the season to reduce the percentage of overwintering flies with resistance; and 5) removing insecticide ear tag as soon as horn fly numbers begin to decline in the fall. Boluses are retained in the cow’s reticulum (second stomach) and dissolve slowly, releasing the insecticide into the digestive tract. When the air temperature is <70°F (21°C), horn flies cluster around the base of the horns of cattle. Do not use ear tags that contain both pyrethroids and organophosphates. We recommend having ear tags on your cows when the number of flies reaches injury level, which is about 200 flies per animal. However, they do have piercing mouthparts like that of the stable fly. The use of some products may not be legal in your state or country. While horn flies are inclined to infest larger animals, such as bulls and adult cow, they will attack calves as well, Boxler says. Horn flies are blood feeders that primarily attack pastured cattle. Producers who want to use parasitic wasps to control horn flies can order fly pupae parasitized with the wasps from insectaries in Texas or across the United States. Each fly takes up to 30 blood meals per day. By: Sonja L. Swiger and Jeffery K. Tomberlin. 1). In Central Texas, horn flies are usually first observed in early spring. Both sexes feed on cattle by taking 20 to 40 blood meals per day. Remarkably, even though horn fly adults feed recurrently on their hosts as ectoparasites, these flies lack the ADP-responsive antiplatelet aggregation and vasodilatory antihemostatic systems described for other blood-feeding Diptera. If you do the math, that adds up to 120,000 bites per cow. Ways to control flies on beef cattle are more diverse than ever. Bulls are more attractive to horn flies than are steers or cows. Read the treatment label to ensure that it is suitable for use on beef or lactating dairy cows. Ready to do something? Feeding causes pain, annoyance, and blood loss in cattle. Horn flies are 3/16 – long and are normally seen on the backs, side, and poll areas of cattle. Bulls usually carry the heaviest infestations. When horn fly numbers are high, cattle experience annoyance and blood loss. Insecticide ear tags are one of the best ways to get rid of flies in your cattle … Research shows that a calf infested with more than 200 horn flies will weigh 15 to 50 pounds less at weaning. Ear tags (Table 1) are 2- to 3-inch plastic tags impregnated with an insecticide and attached to a cow’s ear. Although the average meal size is only 1.5 mg, or 10 µL, of blood per feeding (Kuramochi and Nishijima 1980), each fly takes between 24 to … Studies have shown that horn flies have their greatest effect on growing animals. What do horn flies cost you per year? Beef cattle can weigh 1,000 pounds or more, so it is ironic one of the most detrimental antagonists to cattle are insects weighing only milligrams. Spring rains ensured a bloom of various parasites, including flies. Horn flies rest on a cow between feedings; stable flies remain on the cow only while feeding. Horn flies are one of the most economically damaging external parasites in beef cattle operations in Florida. Confined and free-range cattle can be given feed additives that suppress horn flies. Both sexes feed on cattle by taking 20 to 40 blood meals per day. Without some type of fly control program, every animal in a herd may have several hundred horn flies by mid- to late summer. The bites from these insects are painful and will cause cattle to stomp their feet or bunch together in … Horn flies can affect performance and rate of gain as cattle spend more time under trees or in water looking for relief. Weight gain in dairy and beef cattle. IPM relies on multiple tactics including cultural, biological, and chemical methods to suppress insect pests. To suppress horn flies effectively and economically: Horn flies look like house flies and stable flies but are slightly smaller (Fig. Like the horn fly this is a blood feeder that is a serious problem on feedlots, dairies, as well as pasture cattle. A walk-thru fly trap has been shown to reduce horn fly numbers. Producers who want to use parasitic wasps to control horn flies can order fly pupae parasitized with the wasps from insectaries in Texas or across the United States. Texas A&M Veterinary Medical Diagnostics Laboratory, Texas A&M College of Agrculture and Life Sciences. Another method for controlling horn flies is boluses, which look like large pills. Studies conducted in the U. S. and Canada have shown horn flies can impact calf weaning weights from 4 … However, they have a well-documented close association with cattle and typically remain on or near cattle throughout their entire life cycle. Most of these programs involve commercial insecticides which kill them by disrupting vital nerve functions. They can help to reduce the population of the flies. Wasps sold for fly control around stables and feedlots are impractical for pasture pests, such as the horn fly. Horn flies look like houseflies and stable flies, but horn flies are slightly smaller. 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