Plants have been known to respond to sound in general, but a team of scientists recently discovered that they react to caterpillar’s chewing noises in a very specific way.
“When they were attacked by caterpillars, the plants responded with much higher levels of these mustard oils, which are toxic to caterpillars.” stated Rex Cocroft, a professor in the biological sciences department at the University of Missouri.
To make sure the chemical reaction was incident-specific, the scientists set up an experiment. After establishing their constants and variables, they put a caterpillar on a small, flowering plant. They took leaf-movement measurements and took audio recordings as the caterpillar fed and then tested the plant’s leaves.
In the next stage, the plants were split into groups and each was introduced to a variety of noises and vibrations. Some were played the recordings, while others got sounds and tremors of other insects and rustling wind. One group was left in silence.
Only the ones that had listened to the caterpillar recording were quicker to react when they were reintroduced to the pesky creatures.
The scientists aren’t sure how plants pull it off, but plan to conduct more experiments to get to the bottom of the mystery.
