A new study suggested that common insecticides used for killing bedbugs may not be as effective as thought.

Nature World News wrote that Virginia Tech and New Mexico State University study has discovered that bedbugs have built up a resistance to the general chemicals used for killing the insects because of overuse.

In a news release, Troy Anderson, an assistant professor of entomology in the Virginia Tech College of Agriculture and Life Sciences, said, “While we all want a powerful tool to fight bed bug 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”.

Researchers studied the effects of neonicotinoids or neonics, a class of neonicotinoids that are normally used in combination with pyrethroids for the treatment of bedbugs at a commercial level.

Alvaro Romero, co-author and an assistant professor of entomology at New Mexico State University, added that companies have to be vigilant for clues of declining performance of products containing neonicotinoids. For instance, Romero said that bedbugs persisting on previously treated surfaces could be a hint of resistance.

Two groups of bedbugs were studied by the researchers. The first group belonged to Cincinnati and Michigan homes and had exposure to neonic treatments. The second colony was kept in isolated in a laboratory. They also analyzed a pyrethroid-resistant population, collected from New Jersey and had not exposure to neonics since 2008.

The bedbugs that belonged to the isolated group died after exposure to a little amount of the insecticide, whereas the New Jersey bedbugs showed moderate resistance to the New Jersey bedbugs, with resistance to four distinct kinds of the neonics.

They discovered that the bedbugs brought from Michigan and Cincinnati, which were collected after exposing them to combined insecticides in the US, had quite more resistance to neonics.

Researchers administered over 10,000 nanograms of a chemical called acetamiprid for killing 50% of the bedbugs from Michigan and Cincinnati, while they needed just 0.3 nanograms to kill half of the bedbugs that had been there in isolation.