Figure 4.6 Herbivore-induced responses by plants. (a) The Virginia pepperweed (Lepidium virginicum) responds to herbivore attacks by growing more leaf hairs, known as trichomes, and more types of defensive chemicals, called glucosinolates. (b) Plants attacked by herbivores in the past developed more trichomes and glucosinolates and have fewer aphids on them than plants that were not previously attacked by herbivores. Error bars are standard errors.
After A. Agrawal, Benefits and costs of induced plant defense for Lepidium virginicum (Brassicaceae), Ecology 81 (2000): 1804–1813.