The Cockroach Approach: How Insects Got Everywhere

We at Wknd weren’t sure about venturing here, but the story is so fascinating that we had to give it a try.

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It turns out that the German cockroach, now the most common variant on the planet, would never have sunk so far (oh, the horror), if it weren’t for humans.

A study of 281 cockroaches from 17 countries on six continents, published this year in the journal Proceedings of the National Academy of Sciences, found that this species, Blattella germanica, evolved about 2,000 years ago from the Asian cockroach (Blattella asahinai ), found in the Bay of Bengal regions of India and Myanmar.

He traveled from there, presumably with his boots, bags and pockets full of trinkets from armies and traders, and ended up further and further from home as trade routes developed, and further as the European colonizers appeared with pockets of their own.

The species was first classified by the Swedish biologist Carl Linnaeus in 1776, and was given its misleading name because Linnaeus collected his specimens in Germany and believed they had spread from there around the world .

The German cockroach turned out to be the most dominant strain in Europe, but later studies showed, rather confusingly, that there seemed to be no close relatives. Their genetic markers do not match those of most cockroach species native to Europe.

The mystery lingered until recently when a global consortium of scientists from Singapore, the US, China, India, Russia, Japan, Indonesia, the Czech Republic and Australia decided to work together to find out where they really were the roots of the error. Researchers collected samples and compared DNA sequences until it was confirmed, in this year’s report, that the German bug’s ancestors had indeed been Asian.

Blattella germanica had originally been Blattella asahinai.

He had traveled west, to Europe. It had also traveled east, via Dutch traders and officers of the British East India Company making their way between the new colonies in Southeast Asia. It had crept in and evolved to establish itself around the world.

In another interesting twist, housing evolution would also work perfectly.

As home improvements in the 18th and 19th centuries brought plumbing indoors, and as heating became electric, cockroaches found plenty of food and cozy nooks, in pipes, drains, attics and cupboards.

This allowed the Asian German cockroach to “colonize regions that had previously been inaccessible due to … poor cold tolerance,” the report states.

Since we’re on the subject of pests, we might also mention that the “Norway” rat colonized the world in a similar way, drifting further and further away from its original home in central Asia, probably China, amid a boom of international and maritime trade. activity

And, as Wknd reported in an earlier story, the cat would follow the rat, but from the Mediterranean basin out, as hungry sailors recruited local felines to help keep rodent populations in check. The cats, presumably bored, came out to various ports along the way, and so most of the world’s domestic cats have DNA traceable to this region.

Well, that’s your pleasure for getting this far. Click here for the rest of this story.