(Corrects first, ninth paragraphs to make clear the entire genetic map was not sequenced)
WASHINGTON Jan 19 (Reuters) - Researchers in the United States have sequenced most of the genetic map of the bed bug, and said they may be able to find out how and why the little pests can survive strong pesticides.
The gene map has provided some prime suspects for genes that confer resistance -- the ability to survive poisons, the team at Ohio State University reported Wednesday.
"The resurgence of bed bugs poses an urgent situation as infestations are rampant globally, nationally, and locally," they wrote in the Public Library of Science journal PLoS ONE.
"The control of these medicinally important insect pests in urban environments costs billions of dollars annually and typically requires the use of large quantities of pesticides/insecticides."
The bloodsucking bugs, which can cause itching but do not transmit serious diseases, have made a comeback in cities such as Paris and New York in recent years. [ID:nLDE6AF1XH]
"During the past decade or so, the resurgence of C. lectularius has been recorded across the globe including North America, Europe, Australia, and Eastern Asia with an estimated 100 percent to 500 percent annual increase in bed bug populations," the researchers wrote.
Most cases appear to come from multi-unit apartment complexes, they said.
They said several hypotheses had been proposed to explain the sudden resurgence of C. lectularius worldwide, including frequent international travel, increased exchange of used furniture, a shift from usage of broad-spectrum insecticides to more specific and selective control tactics such as baits for other urban pests, and insecticide resistance within the insect.
Xiaodong Bai and colleagues at The Ohio State University sequenced the genome of the bug, known scientifically as Cimex lectularius.
They especially looked for genes that might help the creatures survive pesticides. "Resistance of C. lectularius to insecticides/pesticides is one factor thought to be involved in its sudden resurgence," they wrote.
There are some potential candidates, and more study may help experts find better ways to kill the tiny bugs, which are extremely difficult to eradicate, they wrote in their report, available freely here
"While bedbugs are poised to become one of the major household pests across the United States in the coming years, we know very little about their genetic makeup and their mechanisms of resistance to insecticides," said Omprakash Mittapalli, who worked on the study.
"Pinpointing such defense mechanisms and the associated genes could lead to the development of novel methods of control that are more effective," Mittapalli added in a statement.
(Reporting by Maggie Fox, Editing by Sandra Maler)