Plants and arthropods: friends or foes ?

Plants are the most abundant terrestrial food sources, and arthropods (insects and arachnids) their most abundant consumers. For this reason plants are heavily defended by thorns, thick impervious coverings, and extraordinary toxins. However, plant fitness also depends upon alliances with arthropods (for pollination and the consumption of herbivores by carnivorous arthropods). The tension between alliance and conflict, or friend and foe, makes the study of plant-arthropod interactions particularly fascinating. This lecture explores this tension, with a particular emphasis on the chemical ecology of these interactions.