Drought-stricken plants emit sounds that guide insects’ egg-laying choices

Research published Nov. 14 via bioRxiv indicates that ultrasonic sounds produced by drought-stricken plants may play a role in female moths’ decision to lay eggs. It has been suggested that these loud sounds, undetectable by humans, are evaluated by moths to avoid dehydrated plants when selecting suitable hosts for their caterpillars.

According to a report in the New York Times, the study was led by entomologist Ria Seltzer of Tel Aviv University, whose team investigated whether the ultrasonic clicking sound of stressed plants could affect the behavior of the Egyptian cotton leafworm moth (Spodoptera littoralis). Can. , The experiments were conducted in a controlled environment where moths were exposed to a speaker emitting sounds that mimicked dehydrated tomato plants. It was reported that in the absence of actual plants, moths lay eggs close to the speakers emitting these sounds.

Observations with Live Plants

In subsequent experiments, live tomato plants were introduced, with a hydrated plant on one side of the test field and a water-deficient plant on the other. The moths were observed laying eggs more frequently on healthy plants. Another setup involved placing hydrated plants on both sides while emitting artificial stress sounds on one side. It was found that moths preferred silent plants over artificially stressed plants.

According to the researchers, this indicates that the moths not only detect these ultrasonic signals but also link them to the physiological state of the plants. It was further noted that moths reared entirely in laboratory conditions, without prior exposure to plants, displayed this behavior, highlighting its genetic basis.

Implications for pest management

Biologist Björn Thorin Jonsson of the University of Graz told the NYT that insects could use widespread and reliable acoustic signals to better locate resources. Fernando Montealegre-Zapata, a sensory biologist at the University of Lincoln, suggested that these findings could have applications in agriculture. He questioned whether stress sounds could be used to deter insects from laying eggs on healthy crops.

Rhea Seltzer told the publication that the discovery could represent the beginning of uncovering acoustic interactions between plants and insects. It was proposed that similar behavior may be widespread in other insect species, with potential implications for ecological research and agricultural innovation.