How Cockroaches Lost Their Sweet Tooth—Fast
Glucose-averse roaches emerged in as few as 5 years: study
By Arden Dier, Newser Staff
Posted May 24, 2013 5:31 AM CDT
The head of a male German cockroach, pointed toward a flavored test substance dyed blue by researchers.   (AP Photo/Ayako Wada-Katsumata, Andrew Ernst)

(Newser) – We're not so lucky as to have a genetic mutation that keeps us away from sugar—but that's the case with some cockroaches, which scientists reveal have quickly evolved in a way that keeps them away from glucose, a popular ingredient in roach-poison bait. That cockroaches have grown resistant to a poison would be relatively unremarkable, reports the New York Times; what makes this a "fantastic discovery," in the words of an entomologist not involved in the study, is that the bugs developed an aversion to any bait with glucose in it. The behavior was first spotted in Florida in the 1980s, reports the AP, which marvels that the trait became widespread in as few as five years, or 25 generations of cockroaches; and it's finally been explained by a trio of US researchers.

They studied German cockroaches, and found that roaches had evolved such that when their taste hairs encounter the sweet glucose, nerve cells register a bitter taste instead, repelling them. (Interestingly, AP notes that the studied cockroaches actually ate most kinds of bait they were presented with, indicating that manufacturers have tweaked their recipes, which are a trade secret.) The research, published in Science, may help explain the behavior of other pests, like malaria-spreading mosquitoes, which have evolved to no longer "rest on walls that are treated with insecticide," says one of the scientists; he speculates that his cockroach research could serve as a tool in discovering why.

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May 24, 2013 7:10 PM CDT
How nice, evolution in darn-near real-time. Explain that creationists.
May 24, 2013 5:37 PM CDT
As far as I know, boric acid is the only effective way to control them. Its the ingredient in Roach Proof. The professional exterminators will put it in a powder sprayer and then hit all the cracks in your home with it. They only have to carry a small amount back to kill a colony. We also used a lot of Malathion at our facility. I used it at home in the foundation cracks. Nothing lived in there after I sprayed it. But our manager learned not to spray it inside a building. He ordered me to spray it in one of our lodges before he arrived. It was his lodge. I mixed up the recommended dose and sprayed his whole home. I then checked and there were roach and bug carcasses all over. I vacuumed them up and then left. A week later he arrived and saw that there were no bugs around. He then saw there was no spray residue on his kitchen mirrors. He said he was not going to move into the lodge until he was sure I sprayed it very well. He said to spray it again and well, with a very strong mix. So, I mixed it up 10 times the usual strength. I covered his mirrors with spray and heavily dosed his whole home. Well, he called me to get to the lodge when he arrived. There were a few more bugs on the floors but not as many as before. He then said, "See, I proved you didn't spray, you just said you did." I told him I had sprayed and cleaned up the bugs. He then said that next time I should listen to his instructions. Well, they wound up being his undoing at that camp. They both were sick a lot and he retired after that summer. I would suggest you never use Malathion inside a home or building.
May 24, 2013 12:40 PM CDT
Fun fact: Many species of cockroach have true pregnancies, give birth to live young, and once born the babies crawl up under the mother's wings where she secretes a nutritious milk-like fluid for the babies to suckle.