- News Home
27 November 2013 12:59 pm ,
Vol. 342 ,
The new head of the National Center for Science Education promises to "fight the good fight" against attacks on...
Analyses of the H7N9 strains isolated from four new cases show that the virus is evolving rapidly, heightening anxiety...
In 2009, Jack Szostak shared a Nobel Prize for his part in discovering the role of telomeres, the end bits of...
Science has exposed a thriving academic black market in China involving shady agencies, corrupt scientists, and...
Paper-selling agencies flourish in the aura of reputable businesses. For some scientists, it may be difficult to tell...
Featuring the first lunar rover in 40 years, Chang'e-3 is seen as an important milestone on China's quest to send a...
Data collected by satellites and floating probes have chronicled a 2-decade rise in the temperature and thickness of a...
Cholesterol, the artery-clogging molecule that contributes to cardiovascular disease, has another nasty trick up its...
- 27 November 2013 12:59 pm , Vol. 342 , #6162
- About Us
A Toxin a Day Keeps the Maggots Away
13 March 2009 (All day)
It doesn't take a backbone to know when to swallow your medicine. For the first time, scientists have shown that an invertebrate, the woolly bear caterpillar, can self-medicate when sick. The finding suggests that this behavior may be far more widespread in the animal kingdom than thought.
Evolutionary ecologist Michael Singer of Wesleyan University in Middletown, Connecticut, and his colleagues made the discovery when they noticed that woolly bear caterpillars (Grammia incorrupta) liked to dine on the Arizona popcornflower (Plagiobothrys arizonicus) and other plants loaded with toxic pyrrolizidine alkaloids. The caterpillars were often infested with the larvae of parasitic tachinid flies. Because the toxin seemed to improve the caterpillars' overall survival--even though it impeded their growth--the team wondered whether the alkaloids functioned as a sort of medicine.
In the lab, the researchers provided infested and uninfested woolly bear caterpillars with pyrrolizidine alkaloids or with sugar. Infested caterpillars ate twice as much toxin as their uninfested brethren did, and the alkaloids increased their survival by 20%, the team reports online this week in PLoS ONE. This suggests that when the caterpillars feed on popcornflower and other toxic plants in the wild, they are self-medicating, says Singer.
Humans visit the pharmacy, and chimpanzees plagued by worms are known to swallow rough, bristly leaves to scrape the parasites from their guts. But this new work shows that even "organisms that lack sophisticated central nervous systems can nevertheless prove capable of very sophisticated behaviors," says ecologist Richard Karban of the University of California, Davis.
Singer says that ecologists should take self-medication into account when studying behaviors in the wild. A better understanding of how endangered species derive medicines from their habitats could prove key to conserving them, he notes.