天蛾发出超声波躲避蝙蝠的追捕

For years, pilots flying into combat have jammed enemy radar to get the drop on their opponents. It turns out that moths can do it, too. A new study co-authored by a University of Florida researcher shows hawkmoths（天蛾） use sonic pulses from their genitals（生殖器） to respond to bats producing the high-frequency sounds, possibly as a self-defense mechanism to jam the echolocation ability of their predators.

Echolocation research may be used to better understand or improve ultrasound as a vital tool in medicine, used for observing prenatal（产前的） development, measuring blood flow and diagnosing tumors, among other things. The study appears online today in the journal Biology Letters.

Study co-author Akito Kawahara, assistant curator of Lepidoptera at the Florida Museum of Natural History on the UF campus, said ultrasound has only been demonstrated in one other moth group.

"This is just the first step toward understanding a really interesting system," Kawahara said. "Echolocation research has been focused on porpoises, whales and dolphins. We know some insects produce the sounds, but this discovery in an unrelated animal making ultrasound, potentially to jam the echolocation of bats, is exciting."

Hawkmoths are major pollinators and some are agricultural pests. Researchers use the insects as model organisms for genetic research due to their large size.

Previous research shows tiger moths use ultrasound as a defense mechanism. While they produce the sound using tymbals, a vibrating membrane located on the thorax, hawkmoths use a system located in the genitals. Scientists found at least three hawkmoth species produce ultrasonic sound, including females. Researchers believe hawkmoths may produce the sound as a physical defense, to warn others or to jam the bats' echolocation, which confuses the predators so they may not identify an object or interpret where it is located, Kawahara said.

The study was conducted in Malaysia, which has the highest diversity of hawkmoths worldwide, and funded by a National Science Foundation grant of about $500,000. Kawahara also conducted research in the jungles of Borneo and the lower Amazon.