Biological fly control is a safe, effective weapon for feedyards
By Larry Stalcup
When Van York says, "We haven't sprayed for flies in 10 years," visitors to the 50,000- head capacity Lubbock Feeders LLC find it hard to believe. Sure, there are a few flies abuzz. But it's nothing like a typical feedyard on a spring or summer day. Instead of insecticides, York uses biological fly control built around fly parasites-good bugs that attack fly pupae-to keep the yard's fly problem swatted down.
York is an assistant manager and part owner of Lubbock Feeders. Their location less than 10 miles from Lubbock, Texas, a college town with a population of 190,000, means environmental concerns are especially keen. But most important to York are employee safety and the performance of cattle on feed. The biological control program boosts both.
Flies, whether they're stable, house or other types, are among the peskiest creatures on earth. Each one can carry multiple diseases. They're favorite dish is animal waste. Left uncontrolled, flies, by the zillions, can make life miserable for cattle, especially at a feedyard. Pinkeye and other festers are worsened by fly infestations. The stress caused by excessive flies can reduce cattle performance and ultimately add to the cost of gain.
And that doesn't include miserable working conditions that can result.
Fly control was one of York's responsibilities at Lubbock Feeders in the late 1980s. He also was safety director. The control method he used, fogging alleys with an insecticide, only knocked down flies for a day or two. It also put employees in possible danger of chemical exposure. "We fogged nearly every morning during the fly season, always before cattle were fed," he says. "Employees wore goggles, aprons and gloves for protection. But there was still a chance of exposure to chemicals. Plus, I never felt like we got ahead of fly infestations."
After studying other fly-control options, he packed away the foggers and turned to a professional biological control service, Kunafin, out of Quemado, Texas, on the Mexican border. An "insectary" operated by entomologist
Frank Junfin, the company had been in biological insect control since Frank's father, Joe, founded it in 1959. It had a good reputation with some large cattle feeding corporations.
The parasites, which are of several species (Spalangia and Nigroaenea to name a few), are about 1/8'' long. Their sole purpose is to attack and consume fly pupae. The gnat-sized creatures won't harm humans or animals. Sold in the form of parasitized pupae, they are dispersed from plastic bags or other containers. They will travel up to 80 yards to find their pupae food source.
Junfin's company supplies fly parasites to numerous feedyards, as well as dairy, poultry, horse, hog and kennel operations. Junfin still oversees the Lubbock Feeders program. He says beneficial bugs are amazing. "They seek out the fly pupae and lay their eggs inside as part of their own reproductive cycle," he says. "The fly-parasite larva consumes the fly's larva. The adult fly parasite emerges and repeats the cycle, seeking out other fly pupae."
Eric Acosta, director of Biocontrol Network in Nashville, Tenn., another company that provides a variety of fly parasites and other insect-control methods for livestock and crop producers, says fly parasites "are adaptable to all climates, and they will reproduce in two to three weeks. This constantly reinforces the parasite population."
600,000 Fly Swatters
In the Lubbock Feeders program, every fly hot spot-manure patties, wet spots, fence row-in every feedyards alley is treated. Treating means releasing handfuls of parasites where adult flies are most likely to lay their eggs. "You have to think like a mamma fly," explains Junfin.
He and his crew begin releasing the parasites as spring emerges. The crew releases 25 to 30 bags of fly parasites, or 600,000 or more of the critters, every week. Even though the parasites reproduce, measures must be taken to combat a constant stream of flies that enter the yard with incoming cattle, feed trucks, or the west Texas wind.
"With the life cycle of the fly being approximately 7 to 10 days from egg to adult, going for lengthy periods without releasing fly parasites only allows the emergence of more flies and increased problems," says Junfin.
There are many factors that influence the quantity of fly parasites to be released in a particular area. Temperature, humidity, rainfall, soils, manure management, breeding madia, number and type of animals in confinement, past history, migration patterns, and an operation's overall control expectations are among them.
"The key to a successful fly-control program is to start early, making scheduled releases throughout the fly breeding season," says Junfin. "Use of supplemental control methods such as sugar baits, fly traps, manure and breeding habitat management, etc., are also needed at times."
Manure management, along with the control of weeds, lagoons and other fly breeding havens, is a must if a fly parasite-or any fly - control program-is to work. "Sanitation is a key ingredient to good fly control," says Carl Patrick, Texas A&M Extension entomologist for the Texas Panhandle region. "Fly pests in feedyards could overwhelm any kind of control program, whether it is biological or chemical, if feedyards don't carry out proper sanitation procedures. They must prevent wet spots in alleys and under fence lines if possible, prevent manure from accumulating under fences, and have good weed control. Spilled feed must be scooped up regularly."
Patrick says feedyards should consider biological fly-control programs. "The most common control method is still periodic insecticide applications to remove adult nuisance numbers," he says. "That provides short-term control. Once it wears off, flies will resurge. In a good integrated pest management program, feedyards should consider different means of control. They should try to get by on the least amount of pesticide they can."
Costs of a fly parasite program will vary with each feedyard. Lubbock Feeders pays what equals about 30 cents to 40cents/ head for annual fly control, all of which is performed by Kunafin, Junfin says annual costs can vary from as low as 20cents/head to as high as $1/head for a small feeding operation.
Kunafin and other insectaries, like Biocontrol Network, will also ship containers of the insects at various costs.
As the fly season progresses, different parasite species may be required. "We see different fly problems," says Patrick. "We mainly have stable flies and house flies. But they change in relative proportion as the season goes on."
Other Biological Controls
Acosta, whose company works with major racetracks, large ranches, water treatment plants, zoos and other customers, says manure management can be enhanced by using a product known as diatomaccous earth, a mineral added to livestock feed.
"When it comes out in manure, it acts as an insecticide for flies," he says. "This mineral has sharp edges, that to a fly, is like crawling through razor blades. It can also be used as a dust on livestock coats and acts as a repellent."
Another menace for maggots, he says, is the beneficial nematode. "The nematodes penetrate insects in the soil, reproduce inside the insect and devour it, inside out," he says.
"They then emerge looking for new hosts, namely maggots. They are very effective at reducing maggot populations."
Patrick stresses that no fly-control method will work by itself on a hit-or-miss basis. "There's not going to be any magic bullet to take care of a fly problem," he says. "It must be a well-managed program all season long."
York notes that there is occasionally a need for some minor spraying or fly bait at the Lubbock feedyard when hot spots flare up. But overall, the feedyard is more environmentally safe for its employees, the cattle and to the nearby Lubbock community, he says.
"Before, our insecticide program also killed beneficial insects," he says. "We now see a larger variety of other insects. There is more natural fly control.
"The success of our program is especially evident when our customers ask us, 'Where are the flies?'
"I smile and proudly say 'We don't have any!'"