Meet the the CowVac, an Innovative Way to Protect Cattle from Horn Flies

By Joel Grossman

(A longer version of this article was published earlier at the Biocontrol Beat blog.)

Rest assured, a CowVac is not a veterinary vaccine of some sort that magically provides insect control or renders cows autistic. Instead, it’s a suction device incorporated into a larger trapping apparatus that removes blood-sucking flies from livestock.

Joel Grossman

“Seven years in the making: The Cow-Vac removes horn flies from dairy cattle” was the title of a presentation by North Carolina State University entomologists Steve Denning and D. Wes Watson at a Member Symposium called “Honoring the Career and Contributions of Veterinary Entomologist Donald A. Rutz” at the 2014 Annual Meeting of the Entomological Society of America (ESA) in Portland, OR.

According to the Center for Environmental Farming Systems at North Carolina State University, “This innovative solution is now part of routine cattle management at the CEFS Dairy Unit and has allowed the herd to be insecticide-free for 5 years.”

“The trap removed between 1.3 and 2.5 million flies annually from the research station cattle,” Denning and Watson reported at the ESA meeting. “Prior to the installation of the trap in 2007, the cattle routinely had horn fly populations above 1,000 flies per animal and would require insecticide applications for horn fly control. With a vacuum trap in place, dairy cattle at CEFS have not required or have been treated with an insecticide.”

The following video shows the CowVac in action:

“The first walk-through pasture fly trap consisted of a covered structure designed to brush flies from the animals as they passed through, with the fleeing flies captured in the screened hollow walls,” Denning and Watson said. “Modifications to the Bruce trap have been introduced over the years. These modified traps employ the same basic mode of action; curtains to dislodge flies and light, either natural or fluorescent, to attract flies to a cage, or bug zapper. In addition to curtains, the CowVac uses air pressure to dislodge flies, and vacuum to capture flies, trapping them in a chamber until death.”

So far, the animal-rights movement has yet to recognize a right to food (in this case, animal blood) for biting flies, and the flies die a natural death from lack of animal blood as a food source. But what’s bad for the flies is good for the cows, especially if you want organic milk, butter, meat, yogurt, etc.

Read more at:

CEFS Dairy Unit Develops “CowVac” to Control Horn Flies Without Insecticides

The Story of the CowVac


Joel Grossman writes about ESA conference highlights of a more applied nature (Integrated Pest Management) for the pen-and-ink IPM Practitioner newsletter. His Biocontrol Beat blog is a bit more eclectic, delving into matters such as the historical links between entomology and modern medicine. He also wrote about insect traps for Forbes Magazine editors when they published the American Heritage of Invention & Technology Magazine.

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