Hawkmoths Evolve Genital Ultrasound to Jam Bat Sonar
Repeated independent evolution across the family points to a research-stage defense shaped by long-running pressure from predatory bats.
Updated on Nov. 4, 2026 in Botany
Some hawkmoths rasp enlarged, football-shaped scales on their male genital valves against structures on their abdomens to produce ultrasonic clicks that can disrupt bat sonar. The findings, published in Proceedings of the Royal Society B, are research-stage observations from a study that tested 143 hawkmoth species, 77 of which produced ultrasound.
Why it matters
The defense appears to have evolved independently at least four and as many as seven times within the hawkmoth family, suggesting a strong and repeated evolutionary pressure from predatory bats. The researchers also found that lineages shifting to twilight or daytime activity lost their sound-producing machinery, indicating the trait tracks with when the moths are active.
The study tested 143 hawkmoth species and found 77 produced ultrasound, with the trait arising independently at least four and up to seven times. The estimated origin window spans roughly 5 million to 30 million years, and the figures reflect a comparative survey rather than a single controlled measurement.
The players
Florida Museum of Natural History
A research museum in Gainesville, Florida, whose researchers contribute to comparative studies of insect evolution and sensory biology.
American Museum of Natural History
A major research museum in New York City with extensive entomology and comparative biology collections.
University of Bristol
A research university in Bristol, England, whose scientists have contributed to work on animal acoustics and evolutionary biology.
Milwaukee Public Museum
A natural history museum in Milwaukee with research programs in zoology and evolutionary biology.
The details
Hawkmoths make ultrasound by rubbing specialized scales on their sex organs against a corresponding row of scales on the abdomen, a mechanical action the researchers classify into three distinct methods. All three rely on enlarged, football-shaped scales on the male genital valves, and the team also identified a previously unknown bumpy surface on the insect's underside that contributes to sound production. The clicks are high-pitched sound beyond human hearing that can interfere with the echolocation bats use to locate prey.
Timeline
Genitalia-enabled ultrasound production evolved independently roughly 5 million to 30 million years ago.
The study findings were published in Proceedings of the Royal Society B on November 4, 2026.
The Tech Race
This work places hawkmoth ultrasound within the broader research field of acoustic defenses against echolocating bats, a line of study that has documented sound-based countermeasures in other moth groups. The new comparative survey of 143 species extends that research by mapping how often the trait evolved and how it relates to activity patterns.
The findings are basic research with no consumer products or availability timeline, so nothing changes for everyday users at this stage. The direct practical relevance is limited to researchers in entomology, bioacoustics, and evolutionary biology who may build on the comparative data.
The takeaway
The clearest signal here is that a sound-based defense against bats has arisen repeatedly in hawkmoths, and that losing the mechanism tracks with shifting to daytime or twilight activity. Researchers tracking this line of work can watch for follow-up comparative studies that test whether other moth families show the same pattern.
Further reading
For broader context on how plants and animals evolve sensory and defensive traits, explore our Botany coverage.
Source note: This article includes information reported by Science News.
