When Plants Click, Moths Listen: New Research Unveils Acoustic Communication Between Flora and Insects

Redacción HC
10/09/2025

For decades, scientists have known that herbivorous insects rely on visual and chemical cues to locate host plants. But what if plants also produce sounds that insects can hear—and act upon? A groundbreaking study published in eLife reveals that female moths integrate plant acoustic emissions into their oviposition decisions. This discovery reshapes our understanding of plant–insect communication and opens new doors for sustainable agriculture.

Plants That “Click” Under Stress

Plants subjected to drought or physical damage are known to emit ultrasonic clicks, airborne sounds imperceptible to humans but potentially audible to animals with ultrasonic hearing. Previous work (Khait et al., Cell, 2023) demonstrated that stressed tomato and tobacco plants emit these airborne signals. The unresolved question was whether insects, particularly pests, actually use this information.

The team led by Rya Seltzer and colleagues from Tel Aviv University tested this hypothesis using the cotton leafworm (Spodoptera littoralis), a major agricultural pest equipped with ultrasonic hearing.

Experimental Design: Letting Moths Choose

Researchers released fertile female moths into controlled arenas and offered them binary choices:

• Hydrated plant vs. drought-stressed plant
• Ultrasonic playback of plant clicks vs. silence (without plants)
• Hydrated plant with stress-sound playback vs. hydrated silent plant
• Playbacks with deafened moths (timpana pierced to test dependence on hearing)
• Male moth clicks vs. control, to test stimulus specificity

They tracked egg cluster deposition per night as the main outcome, applying generalized linear mixed models (GLMMs) and additional statistical tests for robustness.

Surprising Results: Context Matters

The findings reveal a strikingly context-dependent behavior:

• Baseline preference for healthy plants: Females laid significantly more eggs on hydrated plants than on stressed ones (p = 0.004).
• Sounds alone attract in absence of plants: When no plants were present, moths were drawn to the side broadcasting plant stress clicks, laying more eggs there (p = 0.0004). Researchers interpret this as moths treating the sound as a general “plant present” cue.
• Hearing is essential: Deafened moths showed no preference (p = 0.55), proving that the behavior relied on acoustic perception.
• With plants present, sound deters: When both options were hydrated plants but one emitted stress clicks, moths avoided the noisy side (p = 0.01). This aligns with their natural preference for healthy hosts.
• Stimulus specificity confirmed: Clicks from male moths did not alter oviposition decisions (p = 0.4), indicating a specific response to plant emissions.

Video tracking also showed females repeatedly switching sides but gradually increasing time spent near playback sources. Gradient experiments confirmed a bimodal distribution of egg-laying around sound sources and feeders.

Agricultural and Environmental Implications

The discovery that pests can detect and respond to plant sounds has enormous potential:

• Acoustic traps for pest management: Farmers could deploy ultrasonic devices mimicking stressed plants to lure moths into designated zones.
• Sound masking to protect crops: Broadcasting counter-signals might reduce egg-laying on vulnerable plants.
• Early drought detection: Monitoring real plant emissions could serve as a bioindicator for precision irrigation, supporting climate-resilient agriculture.

This is particularly relevant for regions like Latin America and the Middle East, where noctuid pests such as Spodoptera frugiperda devastate maize, cotton, and soybeans under increasing drought stress.

Limitations and Future Research

The authors caution that plant–insect interactions are multimodal, with chemical and visual signals often outweighing sound. The experiments used semi-artificial conditions and only one moth species. Future studies should:

• Test field conditions with realistic click rates.
• Explore other pest species to assess generality.
• Investigate whether plants may amplify their clicks to attract predators of herbivores.
• Measure how far ultrasonic signals travel in dense crop fields.

Such research could define the cost-benefit balance of acoustic devices and assess possible effects on beneficial insects such as pollinators.

Conclusion: A Hidden Language in Nature

This study documents, for the first time, that an insect uses plant-generated acoustic emissions to make a critical ecological decision. As the authors state, “female moths incorporate plant acoustic emissions into their oviposition decision-making process” (Seltzer et al., 2025).

The implications are twofold: a deeper understanding of the evolution of moth hearing—originally thought to evolve mainly for bat avoidance—and a new frontier for sustainable pest management.

The notion that plants “click” when thirsty, and that moths “listen” before laying eggs, highlights the vast array of hidden languages shaping ecosystems. For agriculture, it may mark the beginning of acoustic farming strategies that both reduce pesticide use and improve water efficiency.

Topics of interest

Biodiversity