Cockroaches are becoming 'immune' to insecticide, study claims

Gaia Caramazza
The Purdue university research found insects resistant even to pesticides they had not encountered before - AP

One of the most common types of cockroaches in the UK are quickly growing immune to the best insecticides, according to a new study by Purdue University. 

Researchers found the German species of roaches blattella germanica can develop an immunity to toxic substances after exposure to them.

Infamous for having survived a mass extinction that wiped out dinosaurs, cockroaches are once again proving their resilience in the face of man’s arms race against the pest. 

The study published last week found that cockroach offspring were immune to pesticides they had never encountered before. 

Female cockroaches have a three-month reproductive cycle where they can produce up to 50 offspring, making it easy to pass on the resistant gene. 

“We didn’t have a clue that something like that could happen this fast,” said co-author of the study, Micheal Scharf, “developing resistance to multiple classes of insecticides at once will make controlling these pests almost impossible with chemicals alone.”

Scientists tested three different types of insecticide treatments on cockroach populations in the United States, over a six-month period. Even with a mixture of insecticides deployed, the numbers of pests kept growing. 

The study outlines that this resistance will especially affect urban areas and low-income residents, where antidotes to combat the roaches are not as affordable. 

Scharf stresses that an "integrated pest management" is crucial, whereby chemical treatments are used alongside traps, improved sanitation and vacuums.

“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. 

Most will be horrified to hear this, as cockroaches are carriers of harmful bacteria, including E. coli and salmonella. In some cases the presence of the bugs can even trigger asthma in children. 

Appearing on earth 300 million years before mankind, and rumoured to survive a nuclear holocaust, cockroaches are clearly not planning on departing any time soon.