Why Are Some Plants Hairy?

Abstract

Whether we live in a sprawling metropolis or on a rural farm, plants and insects are part of our daily lives, and many of them cannot exist without the other. Insects help plants reproduce via pollination, and plants provide insects with food and shelter. However, plants also require nutrition to grow, develop, and reproduce; and plant-eating insects can damage them. Over millions of years of living together, plants have evolved multiple defense strategies to defend themselves against insects. One such defense is tiny hair-like projections called trichomes. In this article, we explain how plants use their trichomes as a creative and unique weapon to protect themselves from insect herbivores. Trichomes can cause physical injury, release toxic chemical compounds, and even cause internal injury to insects. We also discuss how plant-eating insects counter these plant defenses using their own defenses—leading to a tug-of-war for survival.