The head of a male German cockroach. The insect's taste hairs, which extend from its face, antennae and mouth, contain sweet and bitter detectors that help some cockroaches avoid traps baited with glucose.
Everyone knows that cockroaches are the ultimate survivors, with enough evolutionary tricks up their carapaces to have thrived for 350 million years and to have completely adapted to the human species.
But the nature of the adaptation that researchers in North Carolina described on Thursday in the journal Science is impressive even for such an ancient, ineradicable lineage, experts say. Some populations of cockroaches evolved a simple, highly effective defense against sweet-tasting poison baits: They switched their internal chemistry around so that glucose, a form of sugar that is a sweet come-hither to countless forms of life, tastes bitter.
The way the roach’s senses changed, experts say, is an elegant example of quick evolutionary change in behavior, and offers the multibillion-dollar pest control industry valuable insights into enemy secrets, perhaps even revealing some clues for the fight against malaria-carrying mosquitoes, which are far more dangerous to human health than roaches.
For the rest of the story: http://www.nytimes.com/2013/05/24/science/a-bitter-sweet-shift-in-cockroach-defenses.html?=_r=6&_r=0