Researchers have discovered that female moths listen to ultrasonic sounds emitted by tomato plants to decide where to lay their eggs.
A team from Tel Aviv University found that tomato plants under stress, such as dehydration, emit ultrasonic sounds undetectable to human ears but perceivable by many animals. This groundbreaking study reveals a new form of communication between plants and insects.
In one experiment, female moths were placed between two boxes: one with a speaker playing recordings of ultrasonic sounds from dehydrated tomato plants, and the other silent. The moths showed a preference for the box with sound, indicating they associate the ultrasonic emissions with the presence of a plant, even if it’s stressed.
When their hearing was blocked, the moths no longer showed any preference, confirming that their choice was influenced by the ultrasonic sounds alone.
In a subsequent test, moths had to choose between two healthy tomato plants. One plant was near a speaker emitting distress sounds from another plant, while the other was silent. The moths preferred the silent plant, suggesting they avoid laying eggs on plants signaling stress when healthier options are available.
Interestingly, when given a choice between a silent box and one containing male moths emitting similar ultrasonic sounds, female moths showed no preference, laying eggs in both. This indicates that female moths specifically respond to sounds emitted by plants rather than similar sounds from other moths.
The findings, published in the journal eLife, suggest that acoustic interactions between plants and animals are more widespread and significant than previously understood. The researchers believe this is just the beginning of uncovering the complex ways plants and animals communicate through sound in nature.
