Fly & Insect Control

External Parasites include: mites, biting lice, sucking lice, heel flies, blow flies (screw worms), face flies, horn flies, house flies, horse flies, deer flies, stable flies, black flies, mosquitoes, gnats, gulf coast ticks, lonestar ticks, spinose ear ticks, deer ticks, and dog ticks.  Lice are a typical winter time problem.  Biting lice are the most common, but sucking lice are the most harmful.  After a long infestation, cattle will loose patches of hair. The animals should be treated and then re-treated 2-3 weeks later to break the life cycle. 


Flies can create a great deal of economic loss.  They irritate the cows causing them to fight the insects and cattle will huddle and crowd rather than graze.  Flies can affect milk production and weight gain and are a vector for the spread of disease.  Face flies are the primary cause of pinkeye.  Face flies do not stay on the animals all day, but feed twice a day on the animals eye fluid.  At any given time, a farmer will see 5% to 10% of the face fly population while the rest of the population will retire to other areas of the pasture.  Face flies seldom travel more than a mile from where they hatch.  They are the same size as house and stable flies.  Face flies do not feed on blood, so systemic insecticides are not effective.  Synthetic pyrethroid flytags and topical insecticides on the face area are the best means of control. 

Photo of Face Fly


Horn flies although not responsible for pinkeye are responsible for the largest single economic loss in the cattle industry across the United States because of low average daily gains, as much as 1/2lb per day lost per animal.  Horn flies are biting flies but are not normally associated with the transfer of blood born disease because the fly travels from the host animal to fresh manure to lay their eggs and then immediately back to the same host animal.  The horn fly is smaller than the face, house, and stable fly and remains on the animal 24 hours a day.  The horn fly only lays eggs in cow manure making feed through additives like Altosid® found in Southern States fly stop minerals and blocks an excellent means of control.  Dung beetles also greatly aid in the control of horn fly populations.  Altosid® is also safe for dung bettles while rabon is not.  The life cycle of the horn fly can be as long as 3 weeks in cool weather.  They winter over in the pupal stage under manure piles before emerging in the spring, this is the stage that occurs after the larval stage that is found in manure.  During the summer, eggs hatch in 24 hours, and the fly life cycle shortens to 11 days.


Photo of Horn Fly.


Ticks are responsible for the spread of anaplasmosis, and Lyme disease.  Anaplasmosis is typically associated with ticks, but can also be transmitted by mites, lice, and biting flies. Cattle acting as carriers in the herd make it a reoccuring problem.  Anaplasmosis causes anemia and is more dangerous for older cattle because they don't produce red blood cells as fast as younger animals.  Animals with severe anemia may survive through the summer and fall, only later to die at the onset of winter.  Antibiotics can be used to treat it and vaccines are not available.  Feed through antibiotics like Aureo 4G crumbles can be used for treatment and prevention:


Deer ticks have black legs, and is the tick responsible for spreading Lyme disease.  The disease can also be spread by infected cattle in utero to an unborn calf and through urine to the rest of the herd.  Animals with Lyme disease will move slow, often showing stiffness, and have a fever.  Antibiotics like penicillin can be used for treatment. 


Photo of Deer Tick


Control of external parasites typically is usually done through growth regulators like Altosid®, insecticides, or de-wormers like ivermectin that are parasiticides that work on both internal and external parasites.  Parasiticide de-wormers will not kill face flies or house flies that do not suck blood.  Most insecticides are one of two chemical classes: Organophosphates or Synthetic Pyrethroids.  Synthetic pyrethroids kill faster and in smaller doses than organophosphates, but they also build up resistance faster.  When an insect becomes immune to one synthetic pyrethroid, it will be immune to all synthetic pyrethroids.  It is recommended to use organophosphates one or two years following the use of a pyrethroid.  The bad news is that face flies are not on the cattle long enough for an organophosphate to be very effective.  Examples of synthetic pyrethroids are: Permethrin, Cylence, Saber Extra Fly Tags, Python.  Examples of organophosphates are:  Co-Ral, Patriot Fly Tags (diazinon), Corathon Fly Tags, Rabon, Prolate/Lintox. 


Products are available in dusts, insecticide tags,  pour-ons, sprays, cattle rubs, face fly kits for mineral feeders, and mineral products.  


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