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Fearless Aphids

September 7, 2010

Habituating crop-munching aphids to their own distress pheromone may make them more vulnerable to ladybugs.


Making pests ignore danger. I’m Bob Hirshon and this is Science Update.

As the boy who cried wolf learned, too many false alarms can make people ignore real danger. Now, researchers are hoping to apply this to crop pests called aphids. Georg Jander, of the Boyce Thompson Institute at Cornell University, explains that when aphids get eaten by predators like ladybugs, the dying aphids release an alarm pheromone that warns other aphids away. So researchers tried breeding plants that produce that pheromone, hoping aphids would avoid them.

GEORG JANDER (Cornell University):
What we found, though, is that if the aphids are raised on the plants that produce the alarm pheromone, they become habituated, so they no longer run away from the alarm pheromone.

However, Jander’s team found that the fearless aphids tend to get eaten more by ladybugs. So combining the engineered crops with natural predators may be the best bet. I’m Bob Hirshon, for AAAS, the science society.