Flooding flea habitats with nematodes microscopic, bacteria-wielding worms is an intriguing new wrinkle being employed by PCOs in their never-ending quest to quell this stubborn, pesky foe.
Sending nematode warriors to eradicate flea larvae and pupae, still a somewhat revolutionary concept in the pest control industry, may be the least costly way to prevent reinfestation from outdoor sources, one of the big causes of callbacks when PCOs guarantee flea control.
That's the experience of some Florida pest control operators who regularly treat outdoor areas with millions of microscopic Steinernema carpocapsae nematodes encapsulated in water-dispersible granules. Once sprayed over an area and soaked into the soil, sand, or gravel at a rate of 160 nematodes per square inch (a billion per acre), these live and hungry "hunters" seek out and attack flea larvae and pupae.
The nematodes inject bacteria into the immature fleas. The bacteria kill more than 90% of the larvae and pupae within 24 hours, according to Steve Miller, training and technical director for residential pest prevention and commercial pest elimination for Massey Services, an Orlando-based pest control company that operates 23 offices in Florida and grossed $17 million last year. Once the nematodes destroy all the larvae and pupae, they perish and disappear from the environment, leaving no harmful residue or adverse side effects. The formulated S. carpocapsae nematodes are sold under the trade name Millenium.
"Where this treatment fits, it's amazing," Miller says. "We apply nematodes to even our worst outdoor problem areas only two times a year. They prevent fleas from reaching pest levels between treatments."
Previously, Massey Services had to treat the same areas at least monthly during the season to keep fleas under control, according to Miller. "With virtually no callbacks, we figure this program reduces the cost of flea control for a residence by about $35 per trip during the year," Miller says.
As a result, Massey keeps prices competitive and guarantees control with confidence. "This also fits our program to refrain from introducing pesticides unnecessarily onto our customers' environments," he adds.
GOOD FORTUNE. Both Massey Services and Mug-A-Bug, a 14-year-old company based in Melbourne, Fla., have had dramatic successes with the nematode. Mug-A-Bug, which now dedicates one of its 10 service trucks for Millenium application, first became acquainted with nematode treatments when trying desperately to put an end to a series of callbacks at the home of an outspoken woman with a persistent flea problem, according to Mug-A-Bug President Doug Vander Poest.
"Every week she called us," Vander Poest recalled. "`They're baa-aack,' she'd say. She was driving us crazy and costing us plenty. Finally, we sprayed the nematodes combined with an adulticide. We had no more trouble."
THE COST FACTOR. The cost of treating with nematodes compares favorably with that of treating with premium insecticides and is much less expensive than trying to treat large outside areas with adulticides plus insect growth regulators that have photostability, Miller and Vander Poest agree. "The most costly job is one you have to go back and do again," noted Vander Poest, who is Region IV director for the Florida Pest Control Association.
Both Miller and Vander Poest emphasize that using nematodes to head off future outdoor flea generations plugs a costly gap but does not replace a basic, multipronged strategy for flea control. Indoors, both companies use adulticides and IGRs most frequently a juvenile hormone analog and urge owners to treat animals with veterinarian-recommended products. "To make guaranteed control profitable, you have to stop all flea life stages at every point of reinfestation," Vander Poest observes. IGRs put a stop to pre-adult stages indoors, he adds, "and Millenium gets them outdoors."
Only normal spray equipment is needed to put nematodes to work against fleas, but certain handling and application requirements do apply, according to John King, a sales representative for Biosys, the company that manufactures Millenium. The nematode-containing granules can be easily tank-mixed with most adulticides and applied normally, King says. Massey Services, for example, usually uses backpack sprayers to treat residential yards.
These particular nematodes can be rendered inactive by excessive heat, King cautions. For optimum results, soil temperatures should not average more than 90°F over a 24-hour period. In the South it is best to treat in the late afternoon, King advises.
WETTER IS BETTER. Mug-A-Bug's method of spraying nematodes when rain falls underscores the need for adequate water, either with the treatment or following treatment, to move nematodes into the soil and litter where flea eggs, larvae, and pupae reside. Biosys recommends application with water or irrigation with 0.1 to 0.2 inches of water within 30 minutes of application.
The nematodes are raised in 22,000-gallon stainless steel fermentation vats containing a medium that mimics (to the nematode) the inside of a dead insect. Taken from fermenters, the nematodes remain alive and well through packaging (they are packaged in cases that contain a billion nematodes each) and shipping. Dispersed in water, they hit the ground hungry, immediately seeking out flea larvae and pupae, which they enter and kill within 24 hours. Those nematodes then die when the flea carcass deteriorates. Nematodes that don't encounter flea larvae or pupae survive up to six weeks waiting for more flea eggs to hatch, according to King. If no host is found in that time, they perish and vanish from the environment.
Miller and Vander Poest say there is no odor or other sign that the nematodes are at work except that fleas don't come back. Miller, however, has noted some beneficial side effects. These include apparent activity against other harmful nematodes, such as root-knot and sting species, which attack turf and ornamental plants; plus activity against root weevils, cutworms, webworms, army worms, and billbugs.
GAINING MOMENTUM. Using nematodes to fight fleas is catching on among some PCOs, but is new enough that it has a long way to go to equal the sales volume of other flea control remedies, reports Bill Barrs of Van Water & Rogers in Tampa. "Some PCOs seem skeptical because they haven't had good results with some other biologicals or natural controls," he says. "This product does seem to do what it claims. Every PCO I know who has tried Millenium likes it."
For Massey Services' Miller, it's a big plus that Millenium is a natural control specific to fleas and possibly certain other pests. "Using Millenium, we've been able to eliminate the use of harsh materials outdoors," he says. "People aren't worried that they're hurting themselves or their pets."
Miller and Vander Poest believe that with customers becoming increasingly conscious of the environment, the pest control industry needs to focus on prevention through exclusion and the use of insect growth regulators and natural enemies such as nematodes to stop future generations. "Control with natural biological materials is the way this business is headed," Vander Poest concludes.
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CASE 1 : BULLDOGS & RACOONSSometimes results are dramatic when nematodes are used under the most challenging conditions PCOs encounter. The following is a case in point. "We first used beneficial nematodes at a 5,000-square-foot home where we'd tried every available insecticide over seven years but never could really control fleas," recalls Steve Miller of Massey Services, Orlando. The house stands on 18-inch concrete piers, occupying a big plot of land along the wooded St. Johns River. The owner had two large English mastiff bulldogs that regularly shared their food with eight or nine families of raccoons. The dogs often sought shade and comfort on sandy ground far under the house, and various wildlife occupied the area by night. Shrubs and hedges, natural woods and ground cover, tree litter, and leaf mold all provided flea habitat. The owner, an admirer of wildlife, would not consider measures to control wild animals in the area. "We'd spray every two weeks, but the fleas kept coming back," Miller says. "Fleas made the man's gardener and the dogs miserable." The last straw came in March when the owner brought in a construction crew to build an addition to the house. Fleas chased the crew onto the roof. They refused to resume work until the fleas were gone. That's when Massey Services decided to try the recently introduced nematode product Millenium. Because moisture is needed to carry the nematodes to the soil, cracks, and crevices, Massey had the gardener set sprinklers to water under the house overnight. The following day technicians power-sprayed nematodes over shaded areas in the yard and under the house in 4 gallons of water per 1,000 square feet (200 gallons per acre). "Two days later, the population was decimated," Miller reports. After 30 days Massey made one more precautionary application. No further treatment was made until September, after the summer rains. Miller doubts the 30-day followup was needed. "If we'd had more experience and known then how effective the nematodes are, we wouldn't have made that application," Miller said. "As it was, the owner was happy, the builders came back, and the gardener was ecstatic." |
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CASE 2 : AT THE RACESMug-A-Bug, a 14-year-old Melbourne, Fla., pest control company, enlisted an army of 500 million nematodes to fight along with an adulticide to stop what President Doug Vander Poest calls "the worst flea infestation I've ever seen" at a greyhound race track. During the winter/spring racing season ending July 1, he says, hundreds of dogs occupied a 1-acre site that included 20,000 square feet of roofed kennels, outside aprons, runs, and weed-infested exercise areas. When the season ended, the flea infestation was so intense that it stopped workers who had been sent in to clean up the area, lay new carpeting in the kennels, and make other repairs. The management called Mug-A-Bug. "Minutes after I entered the area, my white pants were covered by fleas," Vander Poest recalls. "They literally turned black." Vander Poest says he guaranteed the job only because previous experience convinced him that the nematodes in Millenium could handle the challenge. Mug-A-Bug sprayed the area the following day when rain was falling, using a mixture of Dragnet termiticide/insecticide to knock down existing adult fleas and Millenium to control larval and pupal stages. Rain and the water carrier moved the tiny nematodes even into cracks and crevices of the concrete aprons, says Vander Poest, who regularly schedules outside Millenium jobs at times when rain is falling. Two weeks later, Vander Poest found no fleas as he walked the perimeter of the kennel area, then crisscrossed it. "There was no flea activity," he says. "That was it. No callback. No subsequent treatment, and one happy customer." |
Massey Services, Maitland, Fla., was featured in PCT's Special White Paper Report. To order a copy, call Fran Franzak at 800/456-0707.
PCT magazine, July 1996
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