Can exotic phytoseiids (Acari: Mesostigmata) disrupt pest control in stable cropping systems?
Abstract: Exotic phytoseiid species (Acari: Mesostigmata: Phytoseiidae) have been moved from continent to continent in protected and perennial agricultural systems. In protected cropping systems, specialized and generalist species have been used argumentatively both curatively and prophylactically. In contrast in perennial crops inoculate releases, with the aim of establishing the natural enemy, were performed. Here we focus on the question: Can the establishment of exotic phytoseiids disrupt pest control? To answer this question, we review the efficacy of biological control efforts with phytoseiids in several case studies, where exotic and indigenous species were used against pests on indigenous host plants and some crops that were historically or recently introduced. Related factors affecting predator establishment, such as intraguild predation and pesticide effects are discussed, as well as the potential negative effects of exotic species releases on biological control and their impact on the indigenous natural fauna. On citrus, apple, grape and cassava exotic phytoseiids have enhanced biological control without negatively affecting indigenous species of natural enemies, except for the case of Euseius stipulatus (Athias-Henriot) on citrus that displaced Euseius hibisci (Chant) in a limited region of coastal California, USA, the latter considered to be an inferior biocontrol agent of Panonychus citri Koch.