COLLEGE STATION - Two Texas A&M AgriLife Research entomologists are among a team of some 80 international scientists whose work in sequencing the genome of the bedbug was published in the scientific journal Nature Communications on Feb. 2.
The AgriLife Research team members from College Station who were part of the two-year project are Dr. Ed Vargo, Endowed Chair in Urban and Structural Entomology headquartered in the Rollins Urban and Structural Entomology Facility, and Dr. Spencer Johnston in Texas A&M University's department of entomology.
The paper, "Unique features of a global human ectoparasite identified through sequencing of the bed bug genome," is available online at http://nature.com/articles/doi:10.1038/ncomms10165 .
According to the paper, the bedbug, Cimex lectularius, has re-established itself as a human parasite throughout much of the world. The causes are linked to increased international travel and commerce and widespread insecticide resistance by the bug.
"Bedbugs are a big pest," Vargo said. "They are very small insects, about the size of an apple seed, that have been associated with humans for a long, long time. They are unique in that they fill a very specific ecological niche and specialize in feeding almost exclusively on human blood."
He said they are active at night and actually administer a slight anesthetic with each bite, deadening the site so as to remain undetected. Reactions such as welts and itching can take a day or two to develop.
"They've been around for thousands of years, but with the advent of modern pesticides they all but disappeared from the industrialized world in the 1950s," Vargo said. "So I grew up not really knowing about bedbugs except for the saying people had, 'sleep tight, don't let the bedbugs bite.' And that to me was cute but very foreign because I'd never experienced bedbugs."
But in the last 20 years, Vargo said, they've come back with a vengeance and are now very prevalent as numerous media reports in recent years can attest. They are in all 50 states in the U.S. and are especially prevalent in low income housing and housing for the elderly.
"As far as we know, they do not vector any diseases," Vargo said. "The bites can cause itching, even scarring in some cases, but psychologically they can have a big impact on people. It's hard to sleep at night if you know the bedbugs are going to come out when the lights go out. Knowing they are there can be very anxiety producing for many people."
Mapping the bedbug genome is a crucial step in regaining global control, Vargo said.
Genes are pieces of DNA within an organism that make it unique, he said. The genome can be likened to the animal's personal blueprint for making a bedbug a bedbug. So by sequencing the DNA -- obtaining the genome -- the team of scientists have identified all the genes that are in a bedbug. They now know which genes are critical for their survival.
"So having the genome is a valuable resource that any researcher in the world now has access to," Vargo said. "This whole approach of targeting genes in organisms for their control is being used across the spectrum of agriculture and urban entomology. This paper provides a publicly accessible resource that scientists can use to develop new and specific targets for bedbug control."
In the meantime, Vargo said, those suspecting a bedbug problem should contact a professional pest control operator, as very few people are successful in controlling the insects themselves.
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Journal
Nature Communications