Have you ever been in a situation where you arduously tried to kill cockroaches in your kitchen with all kinds of insecticides and sprays but they just would not die?
You may have thought that you bought the wrong insecticides but it was not really the case. Apparently, a new study has found the reason why cockroaches are so hard to kill and it can be quite alarming.
Yes, they are evolving and with rapid progress.
According to the study conducted by the Department of Entomology at Purdue University, they discovered that German cockroaches (Blattella germanica) are evolving at a great rate, making them more resistant towards bug sprays and insecticides.
They can also apparently resist chemicals that they have never been exposed to which leads to our worst nightmare — that it can get nearly impossible to kill cockroaches especially ones that scurry past your feet in your house.
“We didn’t have a clue that something like that could happen this fast,” lead author Michael Scharf said.
Scharf also revealed that insect could gain tolerance of otherwise a toxic substance to them within a generation and through contact with similar insecticides.
“We would see resistance increase four- or six-fold in just one generation,” Scharf said.
In the study, they tested out three different treatments of three insecticides, abamectin, boric acid, and thiamethoxam, in cockroach-infested apartments across Illinois and Indiana for six months.
In the first treatment, each of the three insecticides was rotated every month for three months and then repeated. During the second treatment, two insecticides from two different classes were used for six months.
In the third treatment, they used an insecticide which the cockroaches had low-level initial resistance.
In spite of the different treatments used, they did not manage to reduce the populations of the cockroaches and in fact, ten percent of the populations became resistant to the insecticides used.
While the treatments managed to maintain the number of cockroaches, they were unable to reduce the populations.
Their findings were also supported by lab test which had confirmed that the cockroaches had become immune towards the insecticides used.
The study suggested that insecticides alone will not be helpful but rather, they have to be combined with improved sanitation, traps and vacuums to control the insects.
“This is a previously unrealized challenge in cockroaches,” Scharf said.
“Cockroaches developing resistance to multiple classes of insecticides at once will make controlling these pests almost impossible with chemicals alone.”