We can all agree that cockroaches are scary as they are and the flying ones definitely cause fear and panic. We thought that would be all they are, but scientists bring the most horrendous news of all – they are becoming stronger every day.

Scientists from Purdue University report that German cockroaches are becoming harder to kill, because they are developing cross-resistance to insecticides. This can be passed on to their offspring, which mean it will only be a matter of time before they actually become “insecticide-proof.”

“This is a previously unrealized challenge in cockroaches,” Michael Scharf, professor from Purdue University and lead researcher of the study, said in a statement. “Cockroaches developing resistance to multiple classes of insecticides at once will make controlling these pests almost impossible with chemicals alone.”

The study, which was published in the journal Scientific Reports, shows that the researchers tried different insecticides to exterminate the crawlies. This aims to ensure that even though a small percentage of them is resistant to one type of insecticide, at least one of the other classes of insecticide can kill them.

The different insecticides are typically divided into classes that were based on its toxicity, chemical composition and other factors.

The authors said they have tested it over a six-month period at multi-unit buildings in Indiana and Illinois. They were able to keep the cockroach population through rotating insecticides, but they weren’t able to reduce them.

Scharf said the way to fight against this is to diversify pest treatment methods – chemical treatments, traps and improved sanitation among others.

“Some of these methods are more expensive than using only insecticides, but if those insecticides aren’t going to control or eliminate a population, you’re just throwing money away,” Scharf said. “Combining several methods will be the most effective way to eliminate cockroaches.”

The German cockroach is known as a worldwide pest and could threaten the human health by producing asthma-triggering allergens and adds to the unhealthy indoor environment.

Related stories:
– Creepy crawlers: Cockroaches!
– A beginner’s guide to hissing cockroaches as pets
– Japanese man jailed for smuggling insects from Ecuador