Plant - insect interactions and the biological control of weeds

Abstract

Many of the world's most serious weed problems arise following the introduction of plants into exotic habitats. The introduction of natural enemies, particularly insect herbivores, from the native range may control these weeds, and is likely to be the only solution. I propose that the most effective natural enemies will be those that are rare in the native habitat and in most cases a single species will be effective. Improving the ability to identify potentially successful agents through experimentation in the native habitat and using nitrogen fertilization to enhance plant quality and herbivore population density are suggested techniques to improve biological control. Heterogeneity of plant quality and clumped distribution of insects on plants may help in the persistence of agents when weed populations have been suppressed. Biological control is the only solution for many weed problems.