A study on insect pests of pea plants finds that which pest attacks first changes how the plant mounts defenses, how effective those defenses are, and the eventual nutritional quality of the plants. The experiment examined scenarios in which pea plants were first attacked by pea aphid (Acrythosiphon pisum, left) and pea leaf weevil (Sitona lineatus, right). Pea aphid also affects plants by transmitting pea enation mosaic virus. (Aphid photo by Joseph Berger, Bugwood.org; weevil photo by Pest and Diseases Image Library , Bugwood.org)