Biological control sought for ash whitefly

Abstract

Ash whitefly has spread over a large portion of California since the initial infestation was discovered in Los Angeles County in 1988. Populations have grown to high densities on a wide range of host plants, including ash, pear, apple, citrus, and other landscape and fruit trees. The best hope for control appears to be natural enemies: a parasitic wasp and a predatory beetle have been introduced and are being evaluated.