Bedbugs (or “bed bugs”) are a common source of irritation worldwide, especially in hotel rooms. The spread of the biting insects has been facilitated by international travel. Bedbugs (such as Cimex lectularius) are parasitic insects of the cimicid family that feed exclusively on blood. C. lectularius feeds on human blood. The insect derives its name from its preferred habitat — warm houses and especially near or inside beds and bedding. The bugs are very hardy and can last for a year without feeding; moreover, a pregnant female is capable of infecting an entire building.
Outbreaks of the bug are normally dealt with through the use of fumigation or bait traps using insecticides. These methods are typically effective. However, in recent years various insecticides are proving to be less effective. A team of researchers think they know the reason why. The insects appear to be developing thicker skins and these are proving to be relatively impenetrable to the common chemical treatments (a fact borne out by comparative electron microgaphs.)
The more resistant bugs appear to have a thicker exoskeleton called the cuticle. For example, in one study it required just 0.3 nanograms of neonics to kill half of a non-resistant colony; however, it needed over 10,000 nanograms to kill the same percentage of resistant forms of the insects.
To address the growing resistance, scientists are keen to find out the biological mechanism at play so that a drug candidate can be developed for a new generation of insecticides to beat them.
The findings, gathered by Australian researchers, indicate that the level of insecticide required to kill the more resistant bedbugs needs concentrations 1,000 times larger than those needed to eliminate non-resistant creatures.
The research has been published in the journal PLOS One. The research carries the title “Cuticle Thickening in a Pyrethroid-Resistant Strain of the Common Bed Bug, Cimex lectularius L. (Hemiptera: Cimicidae).”
