A Fungus Among Us That Kills Bed Bugs

Over the last decade pest management professionals have seen a large influx of products and technologies aimed at preventing and eliminating the once eradicated bed bug. From heat treatments and mattress encasements to traps, dusts and targeted applications of traditional pesticides, PMPs have a full tool box of options to choose from.

Concerns over resistance to some pyrethroid and neonicotinoid insecticides used by PMPs to eliminate these most unwanted pests from homes, apartments, condominiums, hotels and dormitories have arisen.

To overcome this challenge and possible cross-resistance to other insecticide classes, Penn State researcher Nina Jenkins and her colleagues turned their attention to fungus for a possible answer.

The study, conducted by researchers from North Carolina State University and Penn State University, investigated whether bed bug populations with demonstrated resistance to chemical pesticides would be susceptible to a completely different kind of pesticide, based on the insect-killing fungus, Beauveria bassiana.

“This kind of fungal biopesticide has been demonstrated to be effective against other pests including aphids, thrips, flies and mosquitoes,” says Jenkins.

The researchers evaluated the efficacy of a new formulation of Beauveria on an insecticide-susceptible lab strain of bed bug, and three field-collected strains known to be resistant to insecticides. They found that the fungal formulation was effective against all four of the bed bug strains.

The result of this research and collaboration with pest management professionals is a U.S. EPA-registered product, Aprehend, a fungal biopesticide that causes disease in bed bugs but is harmless to humans and pets. (Editor’s note: As of press time, individual state registrations have not been granted but have been applied for.)

Designed as a barrier treatment, Aprehend is strategically applied in 2-inch wide spray swaths to headboards, bed skirts and box springs through a specially designed, battery-operated spray gun. The low-volume, ready-to-use product requires no water.

Bed bugs will cross the applied 2-inch barrier and pick up the fatal fungal spores, which they will carry back and transfer to other members of the population. The product is not designed for use by consumers.

HOW IT’S ACCEPTED. “It takes three to seven days for mortality to occur from first contact, which is a little longer than traditional pesticides because the fungus has to germinate and penetrate the bed bug’s body,” says Jenkins, who has formed a company, ConidioTec, to market the product to the pest management industry. “The spores stick to the bed bugs in a similar way to walking across sand with wet feet.”

Jenkins adds that it can take two to four weeks to achieve total effectiveness in the field, but lab research shows 95 to 99 percent mortality rates within 14 days. And with the initial barrier remaining effective for up to three months, the need to reapply the product is much less frequent than with traditional pesticides, she says.

PMPs will realize cost-savings by not having to return to conduct two or three repeat applications recommended for standard chemical treatments. Technicians also will have more time to inspect for signs of bed bugs and other pests, and educate clients and their staff or tenants on bed bug prevention and identification, she adds.

Aprehend performs best when used as a targeted application in localized areas where bed bugs will come into contact with the spray residue. “Understanding the likely route the bed bugs will take when seeking a blood meal is an important part of the treatment process,” says Jenkins, who is creating a companion, online training course for technicians.

PREVENTIVE APPROACH. Since the bed bug resurgence started a decade ago, pest management professionals have taken a mostly reactive approach to solving customers’ bed bug issues. The long-lasting residual properties of the product will allow pest management professionals to market a less intrusive, pro-active quarterly service option to commercial clients.

Jenkins says giving PMPs a preventive treatment option that can be incorporated into their suite of bed bug service offerings, especially in bed bug-vulnerable accounts such as hotels, can help them grow their business. “Preventive bed bug treatment services represent another potential revenue stream for pest management professionals and Aprehend’s unique application and mode of action support that.”

Jenkins emphasizes that Aprehend is not designed as a quick knockdown tool for bed bugs because of its longer mode of action and the fact that bed bugs will often die out of sight of the client. “We recommend PMPs use Aprehend in combination with other control measures as part of an IPM program. It could also be a valuable tool for use after heat treatments to prevent re-infestation,” adds Jenkins.

ConidioTec will launch Aprehend at NPMA PestWorld in Baltimore this October. For more information on product availability and state-by-state registrations, visit www.aprehend.com.

The author is a frequent contributor to PCT magazine and can be reached at jfenner@gie.net.