Crunch Crunch

University of Missouri researchers, Dr. Heidi Appel and her colleague Dr. Rex Cocroft,  are collaborating on a project that is looking very carefully at how plant eating insects such as caterpillars communicate with each other and how plants respond to the sounds that are produced by insect predators. They say that their research is basic and not applied meaning they are not directly attempting to replace insecticides. However, one can easily project that if a plant reacts to the crunching sound of a caterpillar and produces chemicals that the Caterpillar does not like, this could represent a panacea, particularly for organic producers. "I spend a lot of time listening to the vibrational soundscape of living plants and figuring out how insects can make use of the information that is present in the mechanical vibrations to find mates or to find prey or to avoid predators. Something that I noticed was that when I was trying to listen to the communication signals of some insects on the plant if there happened to be, unbeknownst to me, a chewing herbivore on the plant, that drowned out everything else. Chewing herbivores like caterpillars or beetle larvae create distinctive, rather high amplitude vibrations that travel through the plant. So in talking to Heidi who explained how she studied how plants recognize that they are being attacked by herbivores and how they respond to that, we began to wonder whether plants themselves could make use of this tremendous amount of information that is contained in the mechanical information that is traveling through their own tissues. So, we decided that the most relevant vibration we could think of was the sounds of the herbivores, their predators, we decided to start with the chewing vibrations of caterpillars.