Drought-stressed plants emit cell-collapse sounds bark beetles use to locate trees.

Evidence

Sounds from stressed nature are not only limited to fire but also can be caused by drought. Thus, plants suffering from drought stress produce special sounds by the collapse of single cells from dehydratation, and these sounds seem to be intercepted by some species of bark beetle to orient their infestation in a stressed tree. — Almo Farina, Soundscape Ecology, 360

Categorization

• QUESTION: Cell-collapse sounds are ultrasonic presumably — how would a beetle hear them, and what does this imply for plant acoustics research methods?
• SEED: Plant ultrasonics as a kind of ‘geophony-born biophony’ signaling channel is underexplored and could extend the acoustic-monitoring framework beyond animals.
• ADDENDUM: Supports the tree-as-infrastructure / listening thread of the trees essay in a non-obvious way: drought-stressed trees are acoustically communicative organisms, not inert structures.
• XREF: connects to: Bark beetles combine long-range chemical with short-range acoustic signaling — Almo Farina, Soundscape Ecology: Principles,…, 788; Drought-stressed trees broadcast ultrasound that may attract insect pests. — Bernie Krause and Almo Farina, Using Ecoacoustic Methods to Survey the…, 83; Leaf veins filter vibratory signals toward the leaf apex as low-pass channels — Almo Farina, Soundscape Ecology: Principles,…, 332 (+3 more)

Broader Connections

• Trees may signal drought through cavitation sound audible to pest insects #corroborates (1.00) — Almo Farina, Soundscape Ecology, 792
• Sound functions as an ecological resource organisms track for survival #expands (0.72) — Almo Farina, Soundscape Ecology, 248
• Rare and defensible sap flows make male beetle territories worth fighting for #complicates (0.72) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 208