FLY CONTROL: solving the problem Before It Starts
May 2005 Volume 14 Number 3
Flies are a major problem for composting facilities. Traditionally, the problem has been solved using chemical pesticides. But Kunafin, a Texas-based, family-operated company, said it has a better way. By introducing wasps that destroy flies at the cocoon stage, flies are destroyed before they are born.
"We have virtually no flies at our site," said Stephen Hunter, production manager for Texas Organic Products (TOP), which has used the Kunafin fly management program for three years. "Before we started this you couldn't walk through here without stirring up flies. They were everywhere."
TOP uses the program at three locations in San Antonio and Austin, Texas. Kunafin has provided fly management services since 1959, but only recently has brought the technology into the composting market.
"We've been getting a lot of calls," said Clifton Castle, sales and service representative and nephew of the company's co-founder, Frank Junfin. People are seeing the benefits to this compared to spraying a lot of chemicals."
The process involves the introduction of small fly parasites -wasps - into the McEntee composting operation. Flies lay eggs in moist places, like compost piles. The eggs transform into larvae (maggots) then into pupa, or cocoons from which adult flies emerge. The wasps attack the flies at the pupa stage, stinging the pupa and laying their own eggs in the cocoon. The wasp larvae feed on the remains of the fly pupa.
The parasites are simple to apply. They are delivered in bags via UPS. "You just open the bag and sprinkle them around the site," Castle said. "The wasps are so small that they can't hurt people or animals. They have wings and a stinger, but they are only the size of a gnat." The price is right too, Hunter said. A bag of wasps costs $20 to $25. TOP applies two bags a week at its operations – a cost of about $2,600 a year per operation.
"We compost stable bedding from race tracks so we pre-treat the bedding as it comes in once a week, then once a week we treat the composting site," Hunter said. "For $50 a week we're able to control flies with 35,000 yards of stable bedding. It's well worth the price."
At the bio-solids composting facility TOP manages for the San Antonio Water System, the program has not had the same results as in the company's other sites. But, it has made a noticeable difference, Hunter said.
"Being right next to a sewage plant makes it a bigger challenge," Hunter said.
Hunter said he has recommended the program to other composters who have reported success.
"They have seen a noticeable difference," Hunter said.
The program began in 1959 when Joe Junfin and his son Frank began some of the first Integrated Pest Management Programs (IPM) in the country, focusing on controlling bowl worms on cotton farms.
"It worked the same way," Castle said. "The parasites would attack the bowl worm eggs before they could hatch. My uncle found an insect that would control flies and we've been working with dairy and poultry farms where the manure draws a lot of flies."
TOP, the first composting company to use the program, has been doing so for three years.
"We've had some interest from other composters, but now we want to make a big impact," Castle said. "When we first started it was like selling snake oil. People are used to using fast acting chemicals and sprays to control flies and it's hard to get people to try something new."
Castle said flies tend to become resistant to chemicals after a while, making chemical applications less and less efficient over time.
"It's better to attack the problem at the source," he said. "The parasites reduce 80 percent of the breeding."
Continuous treatment is necessary to control the continuous breeding of the flies. Flies have a life cycle of seven to ten days and lay up to 2,000 eggs during their lifetime.
The application periods coincide with fly season. In warm climates like San Antonio, the program has to be followed all year. In northern climates, application would be necessary from spring through fall.