Many insects, like caterpillars and leaf beetles, feed on plants. We call these insects phytophagous. Some phytophagous insects eat a variety of plant species, while others specialize in eating only one, or just a few. If the larvae or nymphs feed on plants, the insect mother usually lays her eggs on a host plant. So how do insects find the right plant?
Insects Use Chemical Cues to Find Their Food Plants
We don't have all the answers to this question yet, but here's what we do know. Scientists believe that insects use chemical smell and taste cues to help them recognize host plants. Insects differentiate plants based on their odors and tastes. The chemistry of the plant determines its appeal to an insect.
Plants in the mustard family, for example, contain mustard oil, which has a unique smell and taste to a foraging insect. An insect that munches on cabbage will probably also munch on broccoli since both plants belong to the mustard family and broadcast the mustard oil cue. That same insect would probably not, however, feed on squash. The squash tastes and smells completely foreign to a mustard-loving insect.
