Today, science knows more than 7.5 thousand species of cockroaches. Some of them have long since settled in human dwellings and cause harm to the household, and they are also carriers of pathogens of various infections. One of their representatives is a red cockroach, which is also called the Prusak. It is very widespread and leads a nocturnal lifestyle.
Blattella germanica (Latin name) is becoming increasingly resistant to the use of poison against it. And soon, according to scientists, it may become completely immune to it. According to information published in the journal Living Science, the reason is that this species is gradually developing cross-resistance to many insecticides. We are talking about chemicals that are designed to kill harmful insects.
Experts are alarmed
Pest control (insect killers) have an extensive arsenal of poisons. If one of them does not exterminate cockroaches, they use the other. But recently, it has been discovered that such tactics ceases to operate. This is because the descendants of these insects are born, already having immunity to substances with which they had no contact.
A study has been published in the journal Scientific Papers, which suggests that this immunity appears in just one generation. And this is very alarming for experts. One of the co-authors, Michael Sharf, a professor at Purdue University in the United States, said scientists could not imagine that this could happen so quickly.
The fact that red cockroaches develop resistance to several types of insecticides at once will make control over pests only with the help of chemistry practically impossible. Prusak can produce fifty descendants during the reproductive three-month cycle. And they will be resistant to toxic substances that are not encountered.
Experiment at american university
The study used three different insecticides in three populations of Blattella germanica in two locations for six months. The first group was exposed to one poison, the second to two, and the third to three. In the last group, one insecticide was used for a month for two cycles of three months each.
In the experiment, several generations were observed. We studied the inherited adaptive characteristics of individual caught individuals. As a result, it was found in Purdue University laboratory that the first two populations under the influence of toxic substances either remained stable or increased due to the acquired immunity.
As for the third approach, it turned out to be ineffective for restraining the growth of the population, since the so-called cross-resistance was formed.
Most of all scientists were surprised that the descendants of the third group were not just resistant to the poison that was applied to their parents, but they increasingly became immune to its other species that were not used in the experiment. Researchers saw that insecticide resistance increased four to six times in just one generation.
Surprisingly, Michael Sharf and his team managed to find out that the most effective approach using only one pesticide was in only one experiment, and in the other it did not work - the cockroach population increased.
Big danger
One generation can give birth to numerous descendants, and those, in turn, give rise to the following.And if all of them will adapt to the chemical effects of even previously unused poisons, this will lead to very negative consequences.
After all, cockroaches are not just in themselves unpleasant for humans. They spread a lot of harmful organisms that cause various diseases, such as E. coli. And their excrement contains allergens, which can lead to asthma.
Disappointing conclusion
Ultimately, scientists from Purdue University came to the disappointing conclusion that it would be impossible to cope with red cockroaches only with insecticides in the near future.
Here it is necessary to apply an integrated approach using various traps (electrical, ultrasonic, glue) and carefully observe the requirements of sanitary standards. Some of the methods will cost more than just using insecticides, but if they are not used, then the fight against cockroaches will be ineffective.