NPR : News

Filed Under:

Evolution Saves Cockroaches From Taking The Bait

Most of us are used to thinking that the evolution of living organisms takes millions of years. But in the case of cockroaches, scientists say the resilient pests have a developed a fast-forward mechanism to save their own exoskeleton.

In a newly published study in the journal Science, a group of researchers conclude that cockroaches have evolved to avoid sweet-tasting poisons by making a subtle change in their body chemistry that makes the bait taste bitter to them.

Cockroaches don't have taste buds, but instead taste hairs. According to The New York Times the researchers:

"... concentrated on those [hairs] around the mouth area and on two types of nerve cells that sense tastes and respond by firing electrical signals to the brain. One responds only to sugars and other sweet substances; the other responds only to bitter substances. Whenever a molecule of something sweet attaches to a sweet detector, it fires electrical impulses and the roach brain senses sweetness, which makes it want to eat whatever it is tasting. Whenever a molecule of something bitter attaches to the bitter detector, that cell fires and the brain senses bitterness, which makes the roach want to avoid that substance.

But somehow the roaches had changed so that the glucose made the bitter detector fire."

How long did it take for cockroaches with a sweet hair to go sour on glucose?

The cockroach glucose aversion "first appeared in the early '90s," Jim Fredericks, chief entomologist at the National Pest Management Association, was quoted by The Times as saying. That's shortly after exterminators started using poison baits instead of spraying as the main method of battling roaches, the newspaper says.

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

NPR

Pack These Pages: Three Must-Reads For Summer

Harriet Logan, owner of Loganberry Books in Shaker Heights, Ohio, recommends a graphic novel about trash, a George Eliot classic and a children's book about a bear pianist.
NPR

Why Does Every New Restaurant Look Like A Factory?

The stripped-down look of exposed brick, poured cement floors, and Edison light bulbs is popular in restaurants across America. One reporter dares to ask, "Seriously, why?"
WAMU 88.5

Why Local Nonprofits Haven't Fixed Poverty

As long as there has been poverty, there have been people trying to end it. We explore the obstacles and inefficiencies local nonprofits run into when trying to solve society's stubborn problem.

WAMU 88.5

Can We Trust Our Cars?

There were more airbag recalls this week, and VW has agreed to pay nearly fifteen billion in its emissions cheating scandal. Meanwhile, cars with driverless technology are becoming available, but whether they will make us safer is up for debate. A look at auto safety and consumer trust.

Leave a Comment

Help keep the conversation civil. Please refer to our Terms of Use and Code of Conduct before posting your comments.