Question

Plant responses to herbivory - Pheromones and VOCs

Accepted Answer

chemical made by organism affecting social behaviour (but dont socialise so rarely formed) of other members of same species
e.g used in maple trees (when attacked, releases pheromones absorbed by leaves of other branches so the leaves form callose to prepare, and also leaves of nearby trees prepare for attack in response to chemical signals)
plants form VOCs (volatile organic compounds), which diffuse through air around plant (which uses the chemical signals to defend themselves), usually only made when detecting pest (attracting its predators or acts as pheromone to allow other plants to form VOC before attacked)
e.g when apple trees attacked by spider mites, VOCs formed which attract predatory mites that destroy the pests

Vocs Chemical Trees Leaves Form Plant Made E.G