A team of researchers from Virginia Tech and New Mexico State University carried out a study to assess the resistance that bedbugs have developed against the most widely used pesticides to destroy them. The study reveals that killing bedbugs might just have become tougher than before. The outcomes from the paper ‘High Levels of Resistance in the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae), to Neonicotinoid Insecticides’ appeared in the Journal of Medical Entomology.

“While we all want a powerful tool to fight bedbug infestations, what we are using as a chemical intervention is not working as effectively it was designed and, in turn, people are spending a lot of money on products that aren't working”, said Troy Anderson, an Assistant Professor at Virginia Tech College of Agriculture and Life Sciences.

This is first of its kind research to calculate the resistance of bedbugs to the commonly used pesticides neonicotinoids (neonics), primarily four of them, which were acetamiprid, dinotefuran, imidacloprid and thiamethoxam.

The research involved comparison of pesticides required to kill the bedbugs kept in isolation prior to the insecticide becoming common, with those collected from Michigan and Cincinnati homes. The outcome showed that while 0.3 nanograms of acetamiprid was required to kill 50% of the secluded bugs, over 10,000 nanograms was required to kill the same amount of collected bugs from homes. Furthermore, 2.3 nanograms of imidaclopridwas needed to destroy the isolated bug, but the Michigan bugs required 1,064 nanograms and the Cincinnati bugs needed 365 nanograms.

Thus, it was concluded that the bedbugs collected from the homes required more than 100 to 30,000 times additional insecticides to get destroyed compared to those which were kept in isolation. According to study author Alvaro Romero from New Mexico State University, the deteriorating effects of the insecticides must be taken seriously by the pest control companies.