Media release

From: PNAS

How cockroaches became persistent pests

Researchers reconstructed the spread of a ubiquitous cockroach species from an ancestor in Asia to every inhabited continent in the world. The German cockroach (Blattella germanica), well-adapted to living indoors with humans, is virtually absent from natural, outdoor environments. Despite being first observed in Europe in the late 1700s, the species’ closest relatives are found in Asia and Africa. Qian Tang, Frank Rheindt, Theodore Evans, and colleagues conducted a genomic analysis of 281 cockroaches collected from 17 countries around the world. The findings suggest that B. germanica originated in India or Myanmar around 2,100 years ago, having evolved from the Asian cockroach Blatella asahinai. From the originating site, B. germanica populations expanded westward around 1,200 years ago. Consistent with historical records, the analysis found that B. germanica did not reach Germany until around 250 years ago, before rapidly expanding to the rest of the world around the turn of the 20th century. Industrial advances, such as long-distance travel and indoor heating and plumbing, likely created the necessary conditions for the species to thrive. According to the authors, additional studies of the cockroach genome may yield insights into the species’ resistance to pest control and aid measures to mitigate the impact of infestations.

Article #2024-01185: “Solving the 250-year-old mystery of the origin and global spread of the German cockroach, Blattella germanica,” by Qian Tang et al