Search this website

Sponsored by ...
Beef Reproduction Task Force

Beef Reproduction Task Force

K_State University Research and Extension

All About Discovery!™

College of Agricultural, Consumer and Environmental Science


An Angus Media site.
Meeting coverage brought to you
by the communications team
at Angus Media.

Click here to visit www.Angus.Media

Other Angus Media event sites ...

Sign up for...

Impact of Fly Control

With an 11-to-1 return, fly control is a smart investment.

RUIDOSO, NEW MEXICO (Aug. 30, 2018) — The only flies on the wall during Brandon Smythe’s presentation at the Applied Reproductive Strategies in Beef Cattle symposium were the ones in the pictures showcased in his PowerPoint. In a conference jam-packed with talks on cattle reproduction, Smythe’s presentation stood out. The assistant professor in New Mexico State University’s Veterinary Entomology Research Laboratory encouraged ranchers at the Ruidoso, N.M., event to look at the smaller details in life — the really small details.

“One thing universal about flies is that they suck,” joked New Mexico State University’s Brandon Smythe.

Introducing himself as “the fly man,” he set out to teach ranchers more about these tiny pests.

The three most common species of flies, he explained, are the horn fly, the stable fly and the house fly. Each species has certain traits characterizing it as a pest for certain areas. Besides being dubbed Smythe’s “favorite fly,” he described the horn fly as the largest pest for rangeland cattle and, therefore, the focus of his presentation.

Smythe explained the general life cycle of this particular species.

“They [horn flies] take advantage of the environments we provide for them,” Smythe said. Horn flies are known as obligate blood feeders, meaning they gain nutrients from eating the blood of a host animal. Smythe said a single horn fly will feed between 30 and 40 times a day from its host.

Horn flies spend a majority of their lives in contact with their host. The only time a horn fly will leave the host is for the female to lay her eggs in a fresh pile of manure, Smythe explained. Each female is capable of laying 100-200 eggs.

These eggs will hatch into larvae one to two days later, and the larvae will pupate on the manure for roughly the next week. Adult horn flies emerge two to four days after pupating and return to the host animal, where the cycle continues.

These warm-weather pests may be dormant in the winter, but they distribute widely during the summer months. Horn-fly populations begin to appear in May and taper off in October, a time period Smythe pointed out coincides with breeding and growing seasons. Smythe said ranchers already expect a lot from their cattle, and without proper management of pests, livestock will not be able to perform to the desired level.

In recent studies, Smythe found that while fly populations did not significantly affect the reproductive performance of cattle, they did negatively affect weaning weights in cattle. Further more, Smythe reported his studies showed animals infested with flies also exhibited decreased feed efficiency and milk production.

With more than $11 returned for every $1 spent on fly control, Smythe said there is no reason why ranchers shouldn’t engage in pest management.

With a tool called VetPestX found on, Smythe said ranchers can create a rotational insecticide plan personalized to their herd and home environment. Smythe encouraged ranchers to pursue fly-control methods when fly populations reach a threshold of 200 flies per animal.

For details on Smythe’s presentation — including the proceedings, PowerPoint and video of his presentation — visit the Newsroom at

Editor's Note: This article was written under contract or by staff of Angus Media. To request reprint permission and guidelines, contact the Angus Media editorial team at 816-383-5200.