Ecology and Biological Control

Abstract

Forests are inhabited by a variety of insects and pathogens, but invasivealien pests increasingly threaten both natural and commercial plantations worldwide.Biological control is an important component of the management of invasive pestsin plantation forests. Biological control involves the use of natural enemies of pests,with the aim of establishing self-sustaining populations capable of reducing pestpopulations permanently. There are numerous examples of success in the implementationof biological control for forest insects worldwide. However, it still largelyremains an empirical practice and its claimed success as a key part of integrated pestmanagement, is often elusive. There are several key ecological concepts and relatedhypothesis that are important in the implementation and, ultimately, the success ofbiological control in forest systems. Natural enemy foraging and dispersal behaviourmay determine how effective a given natural enemy is in finding and exploiting a pestpopulation and ultimately its long-term effect on the pest populations. Likewise, therelative impact of bottom-up versus top-down forces on pest population dynamicsand the dynamic patterns displayed will influence how effective and sustainableagent-induced mortality may be. In turn, adopting the conceptualization of invasionecology in biological control, may allow a better appreciation of the population-levelconsequences of the pest- enemy interactions. Generally, ecological processes mayprove important to be considered prior to the implementation of biological controlof forest pests and may help us to better comprehend successes and failures.