Laboratory selection for pesticide resistance in natural enemies

Many arthropod pests targeted in biological control programs inhabit agroecosystems with numerous other pest species for which biological control is not effective. Introduction and establishment of effective natural enemies may not solve a pest problem if provisions are not taken to protect biological control agents from pesticide applications directed at those pests which have no effective alternative controls. In these cases, secondary pest outbreaks may occur. When pesticides are applied for pests with effective natural enemies, pest resurgence may occur due to decimation of the natural enemies. When natural enemies are more susceptible to pesticides than their hosts, the probability of resurgence increases. Biological control under these conditions may be improved by modification of environmental factors adverse to biological control (conservation) or an increase in the number or improvement of the fltness of natural enemies (augmentation).1.