A study at Purdue University in the United States has found that the German cockroach, common all over the world, is being born with protection from chemicals it has not yet come into contact with. The study, published in the scientific journal "Live Science" on June 25, concluded that Blattella germanica evolved and developed immunity to new poisons.
"We had no idea that something like this could happen so quickly," study co-author Michael Scharf said in a statement posted on the university's Web site. "Cockroaches that develop resistance to multiple classes of insecticides at one go will make controlling these pests almost impossible if we use only chemicals."
The study was conducted in several buildings in the central cities of the states of Illinois and Indiana (United States), and in the laboratories of Purdue University (USA). All had cockroach infestations. The researchers used various spray combinations and studied multiple generations of cockroaches to reach the conclusion.
German cockroaches, which reproduce rapidly and search for areas occupied by people, are described in the report as "the species that gives a bad name to all other cockroaches."
Preventing these now-called 'super-cockroaches' from spreading bacteria and disease in the future will depend more on traps than on chemicals, the report suggests. A German cockroach can lay 400 eggs for a lifetime. The good news is that, despite having wings, this apparently evolutionary species of cockroach "rarely flies," according to researchers.