WEDNESDAY, Jan. 19 (HealthDay News) -- Scientists studying the
genetics of bedbugs believe they know how the critters become
resistant to pesticides, and the finding could someday help drive
them from homes, stores and offices across the United States.
"We are starting to scratch the genetic makeup of the bedbug," said lead researcher Omprakash Mittapalli, an assistant professor of entomology at the university's Ohio Agricultural Research and Development Center in Wooster. "This will give us a better understanding of the biology of the insect."
It was thought that a DNA mutation made bedbugs resistant to
many pesticides, Mittapalli said. But these new findings suggest
many genes have helped the insect adapt to commonly used
pesticides, such as pyrethroids.
"Pesticide resistance is more complicated than we thought," Mittapalli said. It's possible that changes in the gene structure plus expression of other genes are responsible for pesticide resistance, he explained.
Exposure to pesticides actually may trigger genes to react in
defense, leading to a new and dominant strain of
pesticide-resistant bedbugs. This type of evolutionary adaptation
occurs throughout the insect world, and is not unique to bedbugs,
Their findings won't have an immediate impact in the fight
against the blood-feeding insects, Mittapalli said, "but the
genetic basis of some of these genes could be used in new control
Widespread use of DDT and other long-lasting insecticides helped
to control bedbugs after World War II, but over the past decade
their numbers have increased as much as 500 percent in North
America and other parts of the world, according to background
information in the study.
These infestations cost homeowners and businesses billions of
dollars a year and require the use of large amounts of pesticides,
many of them ineffective, Mittapalli noted.
For the study, published online Jan. 19 in the journal
PLoS ONE, Mittapalli's team studied the DNA and RNA of laboratory-raised bedbugs that are susceptible to insecticides and bedbugs previously exposed to pesticides from an apartment in Columbus, Ohio.
The researchers identified 35,646 expressed sequence tags --
many more than previously known -- which are vital in gene
discovery and sequencing. These tags reflect the bugs' diverse
genetic abilities, Mittapalli said. "These are the RNA molecules
being expressed after a good meal of blood," he said.
Bedbug expert Jerome Goddard said "one of the big problems is
that we can't seem to kill them [bedbugs] very well."
The bugs are resistant to the pyrethroid insecticides most pest
controllers use, and "these scientists are trying to figure out
which genes play a role in that insecticide resistance. I guess to
maybe someday manipulate that resistance," said Goddard, an
associate extension professor of medical and veterinary entomology
at Mississippi State University, in Starksville.
Missy Henriksen, a spokeswoman for the National Pest Management
Association, said that any research being done to further
understanding of bedbugs in terms of eradicating them "is all
The current bedbug scourge has its roots in the ease of
modern-day travel, Henriksen said. "Bedbugs need humans for their
very survival," she said. Picking up bedbugs and bringing them home
is the number one way infestations start, she noted.
Growing pesticide resistance means that "a product that may be
effective in killing bedbugs in Kentucky may not be as effective in
killing bedbugs in Ohio," she said.
For now, Henriksen advised calling a professional to rid your
house of bedbugs if you have them.
To prevent them from taking hold in the first place, inspect
furniture or clothing before bringing them into your home, she
said. When you travel, inspect your hotel room for bedbugs and keep
bags off the floor and off the bed, she added.
After traveling, wash the clothes you took on your trip in hot
water or use a hot dryer to prevent any bedbugs from lodging in
your home, Henriksen said. Similarly, because bedbugs have been
found in retail stores, she suggested washing new clothing or
bedding before using it.
For more information on bedbugs, visit the
U.S. National Library of Medicine.