Bed bug numbers on the rise: Rothamsted researcher in Harpenden

Bed bugs. Photo courtesy of A.L. Szalanski

Bed bugs. Photo courtesy of A.L. Szalanski - Credit: Photo Credit: A.L. Szalanski

Bed bugs are biting back against the rising tide of pesticides, a Harpenden scientist has found.

Rothamsted Research scientist Dr Jing-Jiang Zhou has been studying bed bugs

Rothamsted Research scientist Dr Jing-Jiang Zhou has been studying bed bugs - Credit: Photo supplied

An international study, involving an expert from Rothamsted Research, has allowed scientists to read the genetic make-up of the human blood suckers for the first time.

Worryingly, it found an upsurge in the prevalence of bed bugs was linked to the development of resistance to pesticides.

Rothamsted scientist Dr Jing-Jiang Zhou, one of over 80 scientists across the world researching the insects’ genetic make-up, said the findings showed they were adaptive and hardy.

Bed bugs were nearly eradicated after the Second World War in most economically and politically stable countries.

In the past 20 years however, there has been a recovery in their population across much of the world.

The research involved the rearing of bed bugs to extract DNA from their cuticle, which is what forms the outer protective skeleton of the insect.

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This was followed by sequencing, annotation and analyses of the bed bug genetic code.

The outer protective cuticle of bed bugs plays a significant role in their resistance to pesticides.

Researchers identified 273 genes that encode common cuticle proteins, all of which have been associated with pesticide resistance in various other insects.

Genes which respond to chemical stimuli were substantially reduced in the bed bug, compared to insects which feed on plants – a trend which has been noted in other blood-feeding insects.

Dr Zhou, who specialises in insect molecular biology and molecular chemical ecology, said that apart from developing a resistance to pesticides, the upsurge in bed bug numbers was also linked to “international travel for trade, commerce and the frequent exchange of second-hand materials.

“Almost certainly humans and bed bugs will remain closely associated for the foreseeable future.”

The research also showed that bed bugs are extremely hardy as, while they only feed off blood, they can survive an entire year without a meal.

Dr Joshua Benoit, from the University of Cincinnati, and leading author of the work published this month in Nature Communications, warned: “If someone’s home is infested and that person leaves the premises for a few weeks in the hope that the bed bugs feed only off blood, that isn’t going to happen.

“The bed bugs will be hungry and waiting for when the ‘host’ gets back home.”

Dr Zhou said: “As the only British scientist in this study, I am very proud to have contributed to the work.”