Science: Can some bugs listen to plants and then decide what to do?

Egyptian cotton leafworm moth

When some plants are dehydrated or under some other form of stress, they cry a mournful melody made of ultrasonic clicks. Some moths are able to hear those clicks, and researchers now say they have discovered that the insects may interpret the sounds as a cue to choose on which plant to lay their eggs.

“This is new,” said Rya Seltzer, an entomologist at Tel Aviv University and an author of the study. “Plants emit sounds, and insects are really listening to that. They’re tuned to that specific sound, and they know the meaning, and they consider it.”

The defining results arrived when the moths were presented with a hydrated tomato plant on one side of an experimental arena. On the other side was another tomato plant that was healthy and hydrated, but that emitted recorded sounds of distress from a dehydrated tomato plant. The moths, they found, strongly preferred to lay their eggs on the “silent” plant. Dr. Seltzer said that the females not only recognize that these signals indicate the presence of a plant, but also that the moths used the clicks to interpret the state of the plant producing them.

“They have done an incredibly good study,” said Jodi Sedlock, a sensory ecologist at Lawrence University in Wisconsin. “I think they provide very strong evidence that these moths, this species, is attending to those sounds emitted by plants.” But she added that “the reason that they’re attending to them isn’t entirely clear yet.”

As a next step, Dr. Sedlock would like to see this concept studied in nature. “It would be really, really interesting because sometimes what happens in the lab is different.”

This data was reported in a paper entitled, Female Moths Incorporate Plant Acoustic Emissions into Their Oviposition Decision-Making Process.

By Germaine: Bugging people in the name of science