Moth's stealth wings thwart bats

摘要

Some moths aren't so easy for bats to detect. The cabbage tree emperor moth has wings with tiny scales that absorb sound waves sent out by bats looking for food. That absorption reduces the echoes that bounce back to bats, allowing Bunaea alcinoe to avoid being as noticeable to the nocturnal predators, scientists report online November 12 in the Proceedings of the National Academy of Sciences. "They have this stealth coating on their body surfaces which absorbs the sound," says Marc Holderied, a bioacoustician at the University of Bristol in England. Bats sense their surroundings using echolocation, sending out sound waves that bounce off objects and return as echoes. Cabbage tree emperor moths, having no ears that might alert them to a predator, have evolved scales of a size, shape and thickness suited to absorbing ultrasonic sound frequencies used by bats, Holderied and colleagues found.