Biological pest control in organic tree crops in the Western US: an overview.

摘要

Biological control is an economically valuable and naturally occurring pest control service provided by natural enemies that can play a pivotal role in the management of arthropod pests. Natural enemies can be effectively manipulated to enhance biological control through classical introduction (invasive pests only), augmentation and conservation. Classical introductions of exotic natural enemies in western USA orchards have provided long-term successes in the biological control of some groups of invasive pests in tree crops, such as the cottony cushion scale in citrus and the walnut aphid. Periodic release of mass-reared natural enemies to locally augment their activity in western orchards has been successful for California red scale, but in other cases has met with more variable success that is dependent upon the technical effectiveness and commercial viability of the natural enemy species. Conservation of natural enemy activity through selective usage of organic pesticides has also provided opportunities for sustainable pest management in western orchards, such as for spider mites and western tentiform leafminer, with significant economic benefits. Western orchards provide some excellent examples that illustrate the importance and value of biological pest control in organic production that will be presented and discussed in relation to future opportunities for biological control of direct versus indirect pests.