[Seminar Blog] Moths have Radar Jamming Systems?!?

written by: Carter Dierlam

​Professor Akito Kawahara is a Professor, Curator, and Director of the McGuire Center located in Gainesville Florida. The McGuire Center serves as a primary hub for Lepidoptera (Moths and Butterflies) and biodiversity research in the US. Dr. Kawahara studies the evolution and diversity of Lepidoptera. His lab focuses on answering key questions, such as how growing cities and their light pollution affect nocturnal moths, how different moth species fend off bat attacks, and other aspects of their development. A PhD graduate of the University of Maryland, Dr. Kawahara recently visited and presented to the UMD Entomology department to discuss some of his interesting findings. Specifically, he shared his research on the various adaptations moths use to fend off bat attacks. 

Bats use sonar to detect and “see” the things around them; this is how they can avoid trees and find food, which commonly are moths. In response, some moths have developed a strategy to become toxic to bats, so that they won’t be eaten. But what about other species of moths? Dr. Kawahara enlightened us with his investigation uncovering that answer. His team discovered that moths have developed organs that can hear the ultrasonic sound that bats produce when they echolocate. With the ability to hear the bats, the moths can begin evasive maneuvers. They can drop, loop around, and zigzag across the sky. But for some moths, that is not enough.
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Tiger moths (Arctiidae) do not merely go on the defensive. Instead, they counter the sounds that bats produce by generating ultrasonic noise of their own. These moths have an organ that they inflate with air. As it inflates, the ridges on the organ move and produce ultrasonic noise, alerting the bats to its toxicity as a warning to choose another meal.

Tiger moth (Apantesis phalerata, image from Wikipedia)

Another group of moths, the hawk or sphinx moths (Sphingidae), have copied the tiger moth strategy. However, hawk moths generally are not toxic, so bats may not heed any warning. Instead, they use their ultrasonic sound organ to create a loud burst of noise as a bat approaches with ill intent. This noise confuses the bat and disrupts its echolocation, thus “jamming” the signal and allowing the moth to escape. One interesting thing about these sound-producing organs that Dr. Kawahara showed us, is that even though both produce noise, the structure of the organs is different between the two species. (Read more here)1

Male hawk moth (Xylophanes falco, image from Wikipedia)

​A distinctly different defensive mechanism comes from the luna moth. These moths are quite lovely to look at because of their very long tails and bright lime coloring. As the luna moth flies, its tails spin in a circular motion. This motion is not a flight advantage; instead, these tails draw attention from the bats as they use their sonar to hone in on the moth’s location. The action of the tails trick the bat, which swoops in to rip off the tails. With this sacrifice, the luna moth escapes with its life and gets to fly on. (Click here to read more)2

Male Moon Moth (Actias luna, image from Wikipedia)

Aside from their work to uncover anti-bat adaptations, Dr. Kawahara’s research also serves to decipher the genetics and evolution of Lepidoptera. Using this information, his lab, alongside the McGuire Center, works to conserve the diverse incredible moths and butterflies. They serve as pollinators and vital food sources for other species that could disappear if moths and butterflies do. Visit the Florida Museum website to read more about Dr. Kawahara’s work with moths and butterflies. You can also watch Dr. Kawahara in this video from PBS’ series called Bugs That Rule the World.
 

1. A.Y. Kawahara, & J.R. Barber, Tempo and mode of antibat ultrasound production and sonar jamming in the diverse hawkmoth radiation, Proc. Natl. Acad. Sci. U.S.A. 112 (20) 6407-6412, https://doi.org/10.1073/pnas.1416679112 (2015).
2. J.R. Barber, B.C. Leavell, A.L. Keener, J.W. Breinholt, B.A. Chadwell, C.J.W. McClure, G.M. Hill, & A.Y. Kawahara, Moth tails divert bat attack: Evolution of acoustic deflection, Proc. Natl. Acad. Sci. U.S.A. 112 (9) 2812-2816, https://doi.org/10.1073/pnas.1421926112 (2015).

Carter Dierlam is a 1st year PhD student in the Molecular and Cellular PhD program here at the University of Maryland. After graduating from the University of Tulsa with a Bachelor of Science in Biochemistry, he has since joined Dr. Leslie Pick’s lab in the Entomology department at UMD, studying the evolutionary development of insect segmentation. He is currently serving as a Graduate Student Senator for the University Senate and is on the CMNS Diversity and Inclusion Adviosry Board.