Camouflage and mimicry won’t fool a predator that uses echolocation, such as bats. So how do moths outsmart sonar?
A new study shows luna moths spin their trailing hindtails as they fly, confusing the sonar cries bats use to detect prey and other objects.
The research is a first step in understanding why bats are lured into striking a false target and could have implications on sonar development for the military, researchers say.
“This finding expands our knowledge of anti-predator deflection strategies and the extent of a long-standing evolutionary arms race between bats and moths,” says Akito Kawahara, assistant curator of Lepidoptera at the Florida Museum of Natural History at University of Florida.
The study is the first to show that insects use this type of trickery to thwart bats, says lead author Jesse Barber, a biologist at Boise State University. Other animals also might use acoustic deflection strategies.
For the study published in the Proceedings of the National Academy of Sciences, researchers used high-speed infrared cameras and ultrasonic microphones to watch brown bats prey on moths.
Luna moths with tails were 47 percent more likely to survive an attack than moths without tails. Bats targeted the tail during 55 percent of the interactions, suggesting the moths may lure bats to the tails to make an attack more survivable.
While more than half of the 140,000 species of nocturnal moths have sonar-detecting ears that provide a similar level of protection, more than 65,000 species lack this defense, Kawahara says.
“When you pit them against bats, bats can’t find the moths. They go to the tail instead of the head.
“When you look at Lepidoptera collections, you see moths with really short tails and some with extremely long tails. This also is an example of the important role biological collections serve as repositories of patterns and processes of biodiversity.”
Source: University of Florida