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24 April 2014 11:45 am ,
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Major climate data sets have underestimated the rate of global warming in the last 15 years owing largely to poor data...
The tsetse fly is best known as the vector for the trypanosome parasites that cause sleeping sickness and a disease in...
The National Institutes of Health is revising its "two strikes" rule, which allowed researchers only one chance to...
By stabilizing the components of retromers, molecular complexes that act like recycling bins in cells, a recently...
Fossil fuels power modern society by generating heat, but much of that heat is wasted. Semiconductor devices called...
Researchers are gaining insights into what made Supertyphoon Haiyan so powerful and devastating through post-storm...
Millions around the world got a first-hand look at what it was like to be in Tacloban while it was pummeled by...
- 24 April 2014 11:45 am , Vol. 344 , #6182
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Wake Up and Smell the Corn
16 May 2006 (All day)
It may not taste like Starbuck's coffee, but caterpillars apparently have their own version of brew to get them going: plant chemicals. A new study has found that nocturnal caterpillars called Mythimna separate spring to life each evening when they get a whiff of certain plant scents.
Most organisms can tell the difference between night and day simply by taking a look outside. But some may rely on more subtle clues. A few years ago, scientists discovered that corn plants release a different set of chemicals into the air in the morning and evening. Might the M. separate caterpillars, which live on corn plants throughout Asia, use these odors to plan their schedules?
A group of researchers at Kyoto University in Japan decided to test the theory by collecting gas from the plants during the day and at night. They then exposed one set of caterpillar larvae to the daytime fumes and another set to the evening fumes and observed the larvae for several hours. The creatures were almost 50% more likely to go into hiding--which they typically do during the daytime--after being exposed to the "day" fumes than they were when exposed to the "night" fumes. Night fumes made the caterpillars come out of hiding to feed on leaves, their typical evening activity. Surprisingly, changing the lighting conditions had no effect on the caterpillar behavior, indicating that the insects use plant scent alone as an alarm clock, says study co-author Junji Takabayashi.
The caterpillars are believed to have evolved a nocturnal lifestyle in order to avoid predatory wasps that maraud throughout the day, but why they don't use light cues like most other organisms remains a mystery, Takabayashi says. The team, which published its findings online today in PLoS Biology, is now trying to identify the exact chemical compound that the caterpillars respond to.
Scientists are increasingly recognizing the importance of plant chemicals in regulating insect behaviors such as foraging and mating, says James Tumlinson, a plant chemist at Pennsylvania State University in State College. And these findings may have a practical application. Exposing pest caterpillars to certain plant scents may put them to sleep or make them more susceptible to pesticides, says David James, an entomologist at Washington State University in Prosser.