In a world-first study, researchers at Tel Aviv University have discovered an acoustic interaction between plants and insects.
Focusing on female moths, the study found that the insects make critical decisions about where to lay their eggs based on sounds emitted by nearby plants. When plants emit ultrasonic distress signals—inaudible to the human ear but detectable by moths—the moths avoid them in favor of healthy, silent plants.
The study was conducted in the laboratories of professors Yossi Yovel from the School of Zoology and Lilach Hadany from the School of Plant Sciences and Food Security at Tel Aviv University’s Wise Faculty of Life Sciences. It was led by students Rya Seltzer and Guy Zer Eshel, in collaboration with scientists from the Plant Protection Institute at the Volcani Institute. The findings were published in the journal eLife.
The study builds on a groundbreaking discovery published by the same research team about two years ago, which revealed that plants under stress emit ultrasonic sounds—frequencies beyond human hearing but perceptible to many animals.
“After proving in the previous study that plants produce sounds, we hypothesized that animals capable of hearing these high-frequency sounds may respond to them and make decisions accordingly,” said Yovel. “Specifically, we know that many insects, which have diverse interactions with the plant world, can perceive plant sounds. We wanted to investigate whether such insects actually detect and respond to these sounds.”
Hadany added that “we chose to focus on female moths, which typically lay their eggs on plants so that the larvae can feed on them once hatched. We assumed the females seek an optimal site to lay their eggs—a healthy plant that can properly nourish the larvae. Thus, when the plant signals that it is dehydrated and under stress, would the moths heed the warning and avoid laying eggs on it?”
In the first experiment, designed to isolate the auditory component from other plant characteristics such as color and scent, the researchers presented female moths with two boxes: one contained a speaker playing recordings of dehydrated tomato plants, while the other remained silent. The moths showed a clear preference for the ‘noisy’ box, which they likely interpreted as indicating the presence of a living plant, even if it was under stress.
The researchers concluded that the moths do, in fact, perceive and respond to playback of plant-emitted sounds. When the moths’ hearing organs were neutralized, their preference disappeared, and they chose between the two boxes equally—clear evidence that their original behavior was driven specifically by auditory cues rather than other stimuli.
In the second experiment, female moths were presented with two healthy tomato plants—one accompanied by a speaker playing the sounds of a drying plant and the other silent. Once again, the moths showed a clear preference, this time for the silent plant, which emitted no distress sounds.
In another experiment, the female moths were again presented with two boxes—one silent and the other containing male moths, which emit ultrasonic sounds at frequencies similar to those produced by plants. This time, the females showed no clear preference and laid their eggs equally in both boxes. The researchers concluded that, when deciding where to lay their eggs, female moths respond specifically to plant-emitted sounds rather than to similar sounds made by males.
“In this study, we revealed the first evidence of acoustic interaction between a plant and an insect. We are convinced, however, that this is just the beginning. Acoustic interaction between plants and animals doubtlessly exists in many more forms and serves a wide range of roles. This is a vast, unexplored field—an entire world waiting to be discovered,” the researchers said.
