Insects rely on sounds made by vegetation to guide reproduction

Original Article ↗ Hacker News Discussion ↗

Research suggesting that moths can hear ultrasonic sounds emitted by stressed plants has prompted wider reflection on plant–insect coevolution and how little is known about plant signaling. Commenters explore possible evolutionary roles for these cavitation-generated noises, from accidental byproducts to cues that help insects avoid unhealthy hosts, and note that similar signals can now be detected with affordable ultrasonic hardware. The exchange also touches on media sensationalism around “crying” plants, debates over plant consciousness and communication, and ethical questions about how humans relate to and impact ecosystems.

Media coverage & framing

  • Some are surprised a major newspaper is covering a preprint; others note university press offices sometimes push early work.
  • Several commenters distrust “study suggests”–style coverage and feel cautious about unreviewed biology.
  • The article’s use of phrases like “mournful cries” is criticized as misleading anthropomorphism not supported by the underlying paper.
  • Others defend this as normal, evocative popular-science language that assumes readers know plants aren’t conscious and that journalists, not journals, write in this style.

Mechanism and possible function of plant sounds

  • Commenters recall prior work linking plant sounds under stress to cavitation in xylem (tiny bubbles popping as water transport fails).
  • Debate whether this is:
    • Just a mechanical byproduct with no adaptive purpose, or
    • Potentially something that evolution has refined if it had costs/benefits (e.g., attracting or repelling other organisms).
  • Proposed advantages are speculative and include attracting pollinators/seed dispersers near death, signaling other plants, or just being a benign side effect.

Communication, information, and networks

  • Broader plant “communication” is discussed: volatile chemicals, mycorrhizal fungal networks, and defense signaling among trees.
  • There’s argument over what counts as “communication”:
    • Narrow view: requires intent or active signaling.
    • Broad, information-theoretic view: any state change that reliably conveys information (including reflexes) qualifies.
  • Fungal networks are likened metaphorically to “information highways,” though some note that only certain signal types fit a strict information definition.

Consciousness, sentience, and ethics

  • Long subthread on whether plants are conscious:
    • One side: lack of nervous system, evolutionary costs, and current evidence make plant consciousness very unlikely.
    • Others counter that we don’t know what it’s like to be a plant, speculate about distributed awareness, and cite emerging plant-neurobiology-style work.
  • Related debate over human uniqueness:
    • One camp insists humans alone have free will, abstract morality, and selfless compassion.
    • Others cite animal studies (rats, apes, cetaceans, dogs) showing empathy, cooperation, and complex cognition, arguing humans are not unique in kind.
  • Some worry that language about plant “cries” will be used to attack vegetarian ethics, though others say new knowledge should not be suppressed to avoid moral discomfort.

Human–nature relationship & behavior

  • A philosophical thread contrasts “nature in perfect balance” and compassionate stewardship versus views of nature as indifferent and often harsh.
  • Extended argument over hiking off-trail:
    • One side: dispersed use in huge parks has minimal impact and is part of “really experiencing nature.”
    • Other side: trampling, non-native species spread, and studies of alpine damage justify strict stay-on-trail norms; off-trail walking is framed as selfish.
  • Broader critiques of industrial agriculture, inequality, and everyday behaviors (like lawn mowing) as symptoms of alienation from ecosystems.

Detection technology & DIY interest

  • Several commenters explore how to record plant ultrasounds:
    • Stress emissions are said to be roughly 20–200 kHz, with rates on the order of 10–100 clicks per hour under stress.
    • Suggestions include MEMS ultrasonic microphones, high sampling rates (≈384–500 kHz), and repurposing bat-detector hardware.
  • Discussion of sampling theory (Nyquist limits) and why consumer 192 kHz audio gear isn’t sufficient for high-ultrasonic work.
  • A startup founder in the thread claims to be building plant-stress detection products on this principle.

Plant–insect interactions and emotional reactions

  • Core finding discussed: moths appear to avoid laying eggs on plants emitting stress ultrasounds, likely improving offspring survival.
  • Many express awe at this added “dimension” of plant–insect coevolution and link to other sensory channels (e.g., polarization of light in flowers).
  • Some extrapolate speculative ethical or philosophical conclusions (e.g., antinatalism, “nature hates weakness”), while others simply share gardening and wasp-observation anecdotes.
  • Books and interviews on plant behavior and fungal networks are recommended as context for the broader field.