Twospotted spider mite resistance to abamectin miticide on strawberry and strategies for resistance management.

摘要

Florida produces about 2400 ha of fresh-market strawberries valued at about $160 million wholesale in 1997-98. The key arthropod pest of strawberry there is the twospotted spider mite, Tetranychus urticae Koch, which affects almost every field eachyear. Since about 1992, abamectin miticide has been the most effective and most used mite control agent, but it has failed to provide satisfactory mite control on some farms since 1999. Greenhouse and laboratory experiments were performed to determine the resistance status of twospotted spider mites to abamectin on Florida strawberry. Data from these experiments show a ten-fold resistance to abamectin exists in spider mites from affected farms when compared to spider mites taken from strawberry two years earlier and held in a laboratory colony. Strawberry farmers in the region, as a result, are adopting wider use of biological control of spider mites by Phytoseiulus persimilis Athias-Henriot, more informed use of abamectin, increased use of older miticides and are seeking registration of new miticide chemistries.