From the Journal of Experimental Biology comes news that caterpillars are able to force air through their bodies to ‘whistle’ as a defense mechanism when they’re spotted by predators. These aren’t exotic bugs, either: they can be found all over the U.S., even here in Austin, Texas (guess I’d better listen carefully next time I’m in the backyard). From the Nature abstract:
When under attack, walnut sphinx caterpillars (Amorpha juglandis), whistle. An 1868 Canadian Entomologist paper, “Musical larvae,” first reported these shrieks, but their purpose wasn’t clear.
Jayne Yack at Carleton University in Ottawa, Canada, and her team now show that the whistle, produced through openings along the body called spiracles, is a defence against predators. Simulated attacks with blunt tweezers caused the caterpillars to pull their heads back, forcing air through two of the spiracles in a succession of squeaks.
There’s a video of the little guy whistling available in .mov format. I think I’d squeak too if someone was jabbing at me with a pair of forceps…