Introduction

Abstract

Parasites and predators of agricultural pests reduce the population of their prey or host and help to limit damage caused by the pest. Modern plant protection therefore recommends reduction in the use of chemical pesticides to a minimum. If the use of pesticides is indispensable, selective pesticides should be chosen. One of the major aims of the international working group ‘Pesticides and Beneficial Organisms’ of the International Organization for Biological Control of Noxious Animals and Plants, West Palaearctic Regional Section (IOBC/WPRS), which was established in 1974, was therefore to coordinate international activities to develop standard methods to test the side-effects of pesticides on the most important natural enemies and to choose selective pesticides suitable for use in integrated control programmes. Review of the literature published before the IOBC initiative showed that diverse methods, modes of exposure, monitoring techniques and rating systems were used. This made it extremely difficult to summarize and compare results on the side-effects of compounds, but by using standard methods the results of the IOBC testing programmes can easily be presented in clear and simple tables.