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Finding new weapons to kill bedbugs

Mark Feldlaufer, an entomologist at the USDA, is one of the government's foremost researchers on bedbugs. His mission is to find new and existing chemicals to kill the bloodsucking pests.

Washington is also seeing a big increase in calls to 311 and the health department, with the number this year - 257 - on pace to more than double last year's total, officials said.

Traditionally, complaints come from multi-unit dwellings, but the past three months have seen spikes from single-family homes and visitors who stayed in District hotels, they said.

In Ohio, infestations are so severe that Gov. Ted Strickland (D) made two appeals to EPA Administrator Lisa P. Jackson.

"The bedbug problem has created a very real physical, emotional and economically devastating situation for many Ohioans," the governor wrote in a June 30 letter.

One Dayton apartment complex owner spent more than $280,000 in an attempt to destroy the pests, he noted.

Another hired an unlicensed pesticide applicator who saturated the inside of an apartment complex with a pesticide, resulting in tenants being treated at a hospital for chemical exposure.

Strickland would like Jackson to approve the use of an insecticide that is banned for residential purposes. The chemical, propoxur, is widely used to kill cockroaches and lawn pests.

Researching solutions

Although many insecticides are approved for use against bedbugs, the great majority contain pyrethroids, a class of chemicals against which the pests have developed rampant resistance, entomologist Potter said.

Potter's research has found propoxur, which belongs to a more toxic class of pesticides known as carbamates, to be effective because it does not rely on direct contact but remains potent on surfaces where bugs crawl even after it dries. The chemical had been approved for use against bedbugs since the 1960s. But manufacturers withdrew it from residential use in 2007 after the EPA found that indoor uses posed risks to children.

Pyrethroids and carbamates both disrupt bedbugs' nervous systems, but in different ways. University of Kentucky researchers have found that the bugs have developed resistance to pyrethroids in several ways, including breaking down the toxin with enzymes before it reached its targets.

An EPA official said the agency is evaluating more data to find out whether propoxur could be used in a more limited way than Ohio has requested.

The EPA, which held a bedbug summit last year, is now leading an interagency task force on the pests that includes the CDC, USDA, Department of Housing and Urban Development and the Defense Department.

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