Bed Bugs Biting Back!
CBS 42 (Birmingham, AL)
Friday, October 21, 2011
BIRMINGHAM, AL (Ivanhoe Newswire) - You may not be going to bed
alone. After years of winning the war against bed bugs, they're
back! Not only have they returned, but they're stronger and
insecticide resistant. New research from a team at Virginia Tech
has discovered some of the genetic mechanisms for the bugs'
resistance to two of the most popular insecticides used to control
Bed bugs, largely absent in the U.S. since the 1950s, have returned
with a vengeance in all 50 states during the last few decades.
Previously, a class of insecticides, known as pyrethoids, was
successful in controlling the pests. Unfortunately, the new bugs
have developed a resistance to them.
The discoveries will accelerate efforts to understand the
biochemical basis for insecticide resistance in bed bugs. It also
provides molecular markers for surveillance.
"Different bed bug populations within the U.S. and throughout the
world may differ in their levels of resistance and resistance
strategies, so there is the need for continuous surveillance," lead
author Zach Adelman, associate professor of entomology with the
Vector-Borne Disease Research Group at Virginia Tech was quoted as
Two populations of bed bugs were studied. The first, a resistant
population from Richmond, Va., collected in 2008. The second had
been collected in 1973 from Ft. Dix, NJ, and raised in a lab ever
Two popular insecticides, deltamethrin and beta-cyfulthrin, were
used during the study. The researchers determined that it requires
5,200 times more deltamethrin or 111 times more beta-cyfulthrin to
kill the Richmond bed bugs than the lab bugs during a 24-hour
"Deep sequencing of pyrethoid-resistant bed bugs reveals multiple
mechanisms of resistance within a single population," the authors
The research team was able to identify genes that are commonly used
to produce enzymes that can bind to, deactivate, and break down
insecticides. In the resistant bugs, production of some of these
enzymes was turned up significantly.
Mutations were also found in the sodium channel gene of the
resistant bugs. This gene is the target for pyrethoid insecticides.
The mutation makes the bed bug's nervous system partially resistant
to the toxic effects of the insecticide.
"It is reasonable to suggest that the genes responsible for both
acquired insensitivity to these neurotoxicants and their enhanced
detoxification have been selected for in populations that have been
subjected to long-term insecticide pressure," the authors