Cockroaches may seem like they're everywhere, but it didn't used to be that way. Take the German cockroach, one of the main species of the pest found in Hawaiʻi and as far as the North Pole.
It can't fly, and it doesn't live long enough to spend weeks at sea. So how did the cockroach get here?
Scientists analyzed the DNA of nearly 300 German cockroaches from 51 sites, including Hawaiʻi.
They found evidence that the critter had an Asian ancestor over 2,000 years ago. The findings suggest the pests scuttled across the globe by hitching a ride with another species: people.
The study estimates the German cockroaches arrived in Europe about 270 years ago. And though researchers traced the cockroach to Asia, Hawaiʻi's population likely came from the continental U.S.
Harvard University postdoctoral researcher Qian Tang spoke with The Conversation about his team's study.
"There's no difference between the German cockroach in Hawaiʻi and the ones in mainland United States. So to explain that, it seems like commercial or like passengers have brought the German cockroach from the mainland United States to Hawaiʻi, instead of, for example like the next nearby continent is Australia," Tang said.
"We also found that regardless of geographic proximity, the German cockroach populations are more closely related if they have more frequent commercial connection," he said.
His research was published in the journal Proceedings of the National Academy of Sciences.
This interview aired on The Conversation on May 30, 2024. The Conversation airs weekdays at 11 a.m. on HPR-1.
