Sleep tight – unless a thick-skinned bedbug bites

14th April 2016 - A worldwide resurgence in bedbugs since the turn of the century could be down to the pests having developed a thicker 'skin' that allows them to survive exposure to common insecticides, says a study.

Australian research published in the journal PLOS ONE suggests that bedbugs may have developed a thicker shell, or cuticle, as they built up resistance to our chemical assault against them.

Bites

Bedbugs feast on blood and their bite causes red, irritating marks or lumps on the skin of their human prey. They are mainly active at night and hide in crevices in mattresses and even behind wallpaper.

Adult bedbugs resemble a small brown disc that measures up to 6mm in length.

Bedbugs have proved a problem in the tourism industry, particularly in multi-occupancy hotels.

Protective armour

The latest research by David Lilly from the University of Sydney aims to help explain why bedbugs have become more common in the last 2 decades, to help find new strategies to control the pests.

"The new findings reveal that one way bedbugs beat insecticides is by developing a thicker 'skin'," he says in a statement.

He explains: "Bedbugs, like all insects, are covered by an exoskeleton called a cuticle. Using scanning electron microscopy, we were able to compare the thickness of cuticle taken from specimens of bed bugs resistant to insecticides and from those more easily killed by those same insecticides."

When the researchers compared the cuticle thickness of the bedbugs, they found that the thicker the cuticle, the more likely the bedbugs were to survive exposure to the insecticides.

They say their findings may help explain why failures in the control of bedbug infestations are so common and help in the development of more effective insecticides for bedbug control.

"If we understand the biological mechanisms bedbugs use to beat insecticides, we may be able to spot a chink in their armour that we can exploit with new strategies," says David Lilly.

Signs of bedbug infestation

The British Pest Control Association says people can check whether they have a bedbug problem by looking for signs of infestation. These are:

• Red irritating bites, typically in rows on your neck, shoulders, back, legs or arms
• Clusters or dark spots (about 1mm wide) that look like an ink dot, usually found on the bed frame or on the bottom side of the mattress
• Small blood-smears on the bed linen or head-board
• Finding the small brown insects in and around your bed frame and sleeping area.