Cockroaches! Some force to reckon with when they decide to invade your space and chill there, aren’t they? Those detestable bacteria-carrying insects.
They chew the books we cherish reading the most; contaminate our kitchens while we sleep at night; destroy our leather jackets; and to top it off, their favorite hangout joints- dirty toilets and bathrooms- mean they are a grossy bunch of spineless creatures.
Over the years, we have somewhat prevented them from completely taking over by assaulting them with our good old insecticide sprays. However, if Professor Scharf’s research is anything to go by, you may soon have to come up with your own ingenious technique to tackle cockroaches.
The menacing pests have been found to develop cross-resistance to a range of toxic chemicals that have been designed to kill them.
In the six months period the study spanned, researchers tested a variety of insecticides from different classes, as well as a blend of the insecticides in multi-unit buildings in Indiana and Illinois; and realized they were unable to reduce the cockroach numbers even after combining different poisons.
They also found that the insects’ resistance increased up to six-fold within one generation.
The research authors noted that the idea of combining chemicals is to replicate exterminators’ practice of mixing insecticides of different classes to ensure that insects that had developed resistance to a particular insecticide still got killed.
However, the insecticides were able to keep the cockroach populations stable during the study period, but could not reduce their numbers significantly.
Purdue University professor, Michael Scharf, explained their findings: ‘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.
‘If you have the ability to test the roaches first and pick an insecticide that has low resistance, that ups the odds.
‘But even then, we had trouble controlling populations,’ Scharf said.
One of the single-insecticide experiments suggested the population was vulnerable at first; but in another trial with 10 percent starting resistance, the population grew despite treatment and the surviving cockroaches produced more resistant offspring.
Professor Scharf continued: ‘We would see resistance increase four- or six-fold in just one generation.
‘We didn’t have a clue that something like that could happen this fast.
‘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.
‘Combining several methods will be the most effective way to eliminate cockroaches.’