Plants may affect herbivore success directly or
indirectly through effects on their natural
- Insect herbivores often
specialize on a few host plant species.
- The reasons for this
specialization are poorly understood.
- Some authors have proposed
that natural enemies cause herbivore
- This predation hypothesis
proposes that herbivores evolve to prefer plants
on which they are protected from natural
- I tested this hypothesis
using leaf beetles feeding on willows.