Cockroaches boast some impressive abilities: they can move incredibly fast, they can flatten themselves completely to squeeze through small cracks, and their feet are equipped with special adhesive organs and claws that help them climb even smooth vertical surfaces. .
After all, cockroaches are incredibly resilient. A cockroach can support up to 900 times its own body weight, making them almost invincible. Even most pesticides have little effect on them.
And this is a big problem because cockroaches act as vectors for many bacteria, viruses and fungi. They can also trigger allergies. Can cause diarrhea, colitis, hepatitis A, anthrax, salmonella and tuberculosis. Cockroaches also transmit foot and mouth disease.
The victory of the German cockroach
The most successful cockroach – that is, the most widespread around the world – is the German cockroach (Blattella germanica). It is an unwelcome addition to human life on every continent. Up to 2 centimeters (0.8 inches) long and nocturnal, the brown bug prefers particularly dark and damp places. However, it is not found in the wild.
The German cockroach was classified by the Swedish naturalist Carl Linnaeus in 1776, after the Seven Years’ War, when half of Central Europe lay in ruins amid widespread poverty.
He called the insect the “German cockroach” because he had collected specimens of it in Germany.
Until recently, the true origin of the German cockroach was unclear. Now, a team led by Qian Tang from the National University of Singapore has reconstructed the lineage of the cockroach, where it came from and how it spread around the world. Tang and his team of researchers analyzed and compared the DNA sequences of 281 cockroaches from 17 countries on five continents.
Native to South Asia
The analysis revealed that the German cockroach evolved from the Asian cockroach (Blattella asahinae) about 2,100 years ago. The two species are still very similar today. According to the researchers, the insects first adapted to human settlements in India and Myanmar.
From there, the species spread westward over the centuries in two ways. About 1,200 years ago, it benefited from the economic and military expansion of Islam; Then, about 400 years ago, came the expansion from European colonialism, particularly Britain and the Netherlands.
Within months, surviving cockroaches can regenerate entire populations. The life span of a cockroach is only three months on average, so immunity develops incredibly fast as the genes of resistant cockroaches are passed on to the next generation.
