Tomato Plants Can Turn Caterpillars Into Cannibals

A spurge hawk-moth caterpillar. (Credit: Chekaramit/Shutterstock) It's a twist of fate that wouldn't feel out of place in a horror movie: A platoon of caterpillars, young and hungry, descend on a defenseless tomato plant to feast, but as they begin to eat something goes terribly wrong. The leaves no longer satisfy, and they turn on each other in a cannibalistic frenzy — feeding wildly until just one, sated and content, remains. You can read it as a Carrie-like moral parable, perhaps, but bringing out caterpillars' carnivorous tendencies is just sound strategy on the part of tomato plants. Rooted and immobile, plants are easy targets for hungry insects, and they've had to develop other means of defense — like causing their predators to go on the offensive against each other. Plants across the family tree emit an array of defensive compounds to protect themselves — some simply make them less inviting, ...