Studies have shown that the cockroach has developed a resistance to bug sprays and might actually become impossible to control with chemicals.

New research published by Purdue University in West Lafayette, Indiana believes there is a strain of German cockroaches, known as Blatella germanica L, which are becoming difficult to get rid of as future generations are going to be increasingly immune to our efforts to control them.

Scientists have strongly stated that these insects must be controlled as they threaten human health. They can spread bacteria and their feces triggers allergies and asthma in both children and adults.

A Losing Battle

A professor in the Department of Entomology, Michael Scharf, said: “This is a previously unrealized challenge in cockroaches”.  He led a 6-month study that was then published in the Scientific Reports journal.  He believes these insects are becoming resistant to many insecticides which will make controlling them almost impossible using chemicals alone.

This species of cockroaches cannot survive in areas without humans and thrive in warm indoor places with access to food and water.  This statement was made by the University of Florida’s Institute of Food and Agricultural Sciences.

Purdue researchers believe insecticides used to remove the spread come in different classes and each works differently for eliminating cockroaches.  Some of these sprays contain a blend of multiple classes to ensure that at least one will impact these very tough insects.  New experiments are planned to test these sprays’ effectiveness.

German roaches were collected from apartments in Indianapolis and Danville.  Chemicals were purchased from Univar Solutions.  During the first test, 3 kinds of insecticides were rotated for 3 months before repeating the process.  The second test had a mixture of 2 insecticides for a period of 6 months. In the third test, scientists used a single insecticide on roaches that had low resistance and ran the test for another 6 months.

In the first rotation, researchers said they could keep the population down but failed to reduce it.  During the mixture test, nothing worked and instead the population started to grow.

What happened next was really shocking!

In a single insecticide test, scientists discovered they were able to eliminate the roach population because of the low starting resistance in the chosen insecticide.  That said, not all was good news.  With another single insecticide experiment the population with only 10% resistant but managed to grow.

Scharf believes that cockroaches will survive a certain treatment and essentially become immune to the insecticide in the future and that includes their offspring.  They have also gained resistance to other classes of insecticides even if the insects were never exposed to the treatments and never had a previous resistance.

He went on to say that resistance will increase four or six-fold in just one generation.  He said no one had any idea that something like this could happen so fast.

Female cockroaches have a 3-month reproductive cycle which will bring in another 50 offspring. Even a number this small can lead to a lot of trouble down the road.  It is suggested that even if a population is wiped out by one working bug spray, they could spring back in a matter of a few months.

Further research will have to be conducted to come up with a plan for removing cockroaches from the human population.  Chemicals have become a concern among most people, so how strong will a new variety of bug spray have to be to control the problem?  Adding to that, how long would a new bug spray last before these tough insects become immune to that as well?

That said, insects have been around since the beginning of time, so they might just survive us as well!