The Story of the Indomitable Cockroach Is All About Us

This week a story on the history of cockroaches, based on new research published in Proceedings of of the National Academy of Sciences, dominated nature writing all over the country. 

The PNAS article, “Solving the 250-year-old mystery of the origin and global spread of the German cockroach, Blattella germanica,” traces the history of the insect, from its Asian ancestors 2,100 years ago in India or Myanmar to its African foothold and European conquest centuries later, to its ubiquitous presence everywhere in the world today.

The researchers took DNA samples  from 281 German cockroaches from 17 countries to study their genetic differences and track their journey across the planet. The common denominator in the bug’s evolution: human development. The entomologists write, “The rise of human civilization has triggered the evolution and spread of commensal species adapted to urban environments.”

Human technology – transportation, climate-controlled living spaces, and above all, food production – has attracted the cockroach to our side, wherever we’ve settled on the planet. On the other hand, the technology we’ve deployed for decades to keep the pest at bay – namely insecticides – has been mostly ineffective, since the cockroaches’ superpower is to continually develop resistances to our toxins.

Cockroaches are so enamored of our company that B. germanica is rarely ever even seen in the wild. (While the other 4500 or so species of roach avoid us altogether.) 

In the popular imagination, cockroaches are indomitable adapters who will survive anything, including nuclear apocalypse. That story might not be true – for all we know they are entirely dependent on their unwilling and unloving human benefactors. 

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