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Fly Control in Livestock

We cannot wait until a problem exists to begin a fly control program. Flies are among the most difficult pests to control. A good program needs to be in place before fly numbers increase. Often flies are hidden during a portion of their lifecycle making them undetectable. Knowing when and where they may be found increases the ability to limit potential losses in your animal’s performance. Proper identification of the fly and knowledge of the life cycles is important to help to target control measures.

Four flies are the more common ones found around livestock and horse areas. The Horn Fly and Face Fly cause problems in pasture situations, while the House Fly and Stable Fly are a problem around barns and stable areas. Our CVCA speaker will focus on Horn Flies and the latest controls recommended by his company. The Horn Fly is dark gray in color with two transparent wings folded flat over the back, often in a delta wing position. Their life cycle is completed in 8 to 45 days depending on temperature and humidity. The horn fly rests on different parts of the host’s body – on light or dark-colored patches of hair (dark when cool and light when hot) and underside during rain or heat. Horn flies will only leave their host when they lay eggs, move to other cattle in the herd, or when the cattle enter buildings. Most of the feeding occurs along the underline of the animal and often bloody, scabby sores can be seen. The horn fly can feed from 10 to 38 times per day and this results in irritation to the host and decreased grazing time and thus reduced weight gains and milk production.

There are a good number of ways to effectively control flies. In the stores our speaker represents, one can find products in each category which will control horn flies. Sprays ranging from $18–$23 with various types & levels of Active Ingredients. A pour on at $36, a dust @ 8.50/container, dust bags @ $23, a back rubber concentrate @ $44 and a high magnesium mineral with IGR (insecticide growth regulator that controls horn flies) @ 24.50. They also sell a 50 lb. bag of Clarifly for $160 where 2 lb. of Clarifly can be mixed in with a 50 lb. bag of minerals which adds $6.40/bag to the TMR HiMg bag which sells @ $15.50. The real big advantage to this product is it kills not only the horn fly but the other flies also. Folks who use this will mix it in a wheelbarrow or a small cement mixer.

The above mineral products control horn fly larvae in the manure. Depending on
the year, the adult horn flies will still need to be controlled. The last product I
will mention is the ear tags. They carry 5 different type of tags with 3 different
type of Active Ingredient. As we learned in February, we need to rotate the
Active Ingredient on a yearly bases to reduce fly resistance to any product we
are using. Breaking up manure paddies is a “green” tool to help control Horn Fly.
HAY TIP for the month: “As Hay Quality Goes Up, Hay Waste Goes Down”
Like humans, forage-consuming animals have definite preferences regarding
what they eat. Not like humans, there is a high correlation between what tastes
good to animals and nutritional value. Consequently, when animals are offered
hay that is of high quality, they are much less picky and will eat a higher % of
it. The lower extent of refusal and waste (when high-quality hay is fed) further
emphasizes the importance of striving for high hay quality. Do you know the
nutrient value of your hay? “If you don’t test, you will be forced to guess.” Guess
amounts of energy (TDN) and protein needed. Start by borrowing the hay probe
& sampling all hay groups. I will help you get them to Raleigh and assist payment processing.

Horn flies chart imageHorn flies chart image