In a pair of studies published in the science journal Nature Communications, researchers described how bedbug genes have evolved to fight off the most common chemicals used against them.
The teams trawled the DNA of the common bedbug, Cimex lectularius, found in temperate climates in the United States and parts of Europe.
In the first study, scientists at the American Museum of Natural History and Cornell University in New York assembled the first complete genome of the bedbug in all six stages of its life from infancy to adulthood.
They took DNA samples from male and female bedbugs, from preserved and living specimens from as far back as 1973.
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They tested the genes before and after each blood feeding.
And what they found will strike fear into the heart of the toughest pest controller.
"Today, a very high percentage of bedbugs have genetic mutations that make them resistant to the insecticides that were commonly used to battle these urban pests," said Louis Sorkin of the American Museum, one of the study authors.
The troublesome critters have a multitude of genes that render pesticides increasingly ineffective.