Moths can hear sounds emitted by plants and rely on them to choose which plants to lay eggs on, a new study shows.
The analysis, ‘Female moths incorporate plant acoustic emissions into their oviposition decision-making’, was published online last month. This was done by a team of 17 researchers based in Israel.
Ria Seltzer, an entomologist at Tel Aviv University in Israel and one of the study’s authors, told The New York Times, “This is new…plants make sounds, and insects are actually hearing that. They tune in to that specific sound, and they know the meaning, and they make it They think.”
Last year, a study found that some plants emit a mournful melody composed of ultrasonic clicks or pops when they are dehydrated or otherwise stressed. These sounds are undetectable to the human ear but can be heard by other animals, including insects.
How was the new study done?
After last year’s discovery, Seltzer and his team began examining whether a species of moth called the Egyptian cotton leafworm used the clicks produced by stressed plants to decide where to lay their eggs—one of the most important decisions in their lives.
“All of her children are going to develop on that particular choice that she made, and she has to make a quick call and a very good call,” Seltzer told the NYT.
The team showed for the first time that female leafhoppers choose healthy and thriving plants to lay their eggs on because they are more likely to provide adequate food for newborn larvae rather than dehydrated larvae. Once established, they analyzed the role of clicks in important decisions made by these moths.
For this, the researchers used a hydrated tomato plant on one side of the experimental field. On the other side, they placed another healthy and hydrated tomato plant but it emitted distressing sounds.
What were the results of the study?
Researchers discovered that moths prefer to lay their eggs in “quiet” plants. This means that female moths can not only recognize cues that indicate the presence of a plant but also interpret them to decide where to lay their eggs, according to Seltzer.
Jodi Sedlak, a sensory ecologist at the University of Wisconsin’s Lawrence, told the NYT, “They have an incredibly good study…I think they provide very strong evidence that these moths, this species, pay attention to sounds emitted by plants.” However, Sedlock added that “it’s still not entirely clear why they’re paying attention to them.”
Seltzer acknowledged that more research is needed. The next step will be to see how moths can use these acoustic signals in conjunction with scents and other signals from plants. (With inputs from The New York Times)