Cockroaches are challenging the pesticides designed to eliminate them.
A recent study has found that the most abundant of all cockroaches found in the world, the German Cockroaches, are becoming increasingly resistant to most of the insecticides.
Not only did the experimentation backing this research failed to reduce the cockroach population during the 6-month study period, but it also discovered other disturbing facts. It was found that the insect had grown up to six times more resistant to the insecticides with each generation.
Michael Scharf, a professor at Purdue University, said: ‘This is a previously unrealized challenge in cockroaches.
‘Cockroaches developing resistance to multiple classes of insecticides at once will make controlling these pests almost impossible with chemicals alone.’
The research was published in Scientific Reports – a journal focused on the species Blattella germanica L, commonly found in all over the world.
The researchers used different insect killers of different classes, as well as combinations of different insecticides during the study.
It was carried out in multi-unit buildings in Illinois and Indiana over a duration of six months.
The researchers noted that exterminators use mixes of insecticides belonging to different classes to kill the pests so as to make sure the insects having resistance to a certain insecticide can get eliminated by a different one.
For the study, roaches were captured from the target sites and examined in the lab before they were subjected to the insecticides to choose the best treatment for each case.
Professor Scharf said: ‘If you have the ability to test the roaches first and pick and insecticide that has low resistance, that ups the odds, but even then, we had trouble controlling populations.’
The researchers report that they were able to stabilize the cockroach populations during the study period but were not able to significantly reduce their numbers.
The little demons even outlived some multi-insecticide mixtures.
A single-insecticide experiment even suggested that the roaches were first weak against the pesticide but in another trial, where 10 percent had developed resistance, the population spiked, even with the treatment.
The roaches that survived the pesticide, gave birth to even resistant generations.
‘We would see resistance increase four- or six-fold in just one generation,’ Professor Scharf said. ‘We didn’t have a clue that something like that could happen this fast.’
Female roaches are capable of producing up to 50 offspring within a span of just three months.
It means that even a small percentage of resilient beings in the next generation can sustain or even increase the number of roaches in an area.
‘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,’ Professor Scharf said.
‘Combining several methods will be the most effective way to eliminate cockroaches.’