Effects of insecticides and fungicides commonly used in tomato production on Phytoseiulus persimillis

The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is a major pest of agricultural crops worldwide. In several greenhouse systems and conventional agricultural crops in the western US, the biological control agent Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) is used to control twospotted spider mite populations. In the last several years a P. persimilis population has established itself in Rowan County, North Carolina, a region of high commercial tomato (Solanum lycopersicum) production. Phytoseiulus persimilis was collected from western NC and screened against insecticides and fungicides commonly used in commercial tomato production to determine the lethal impacts of topical exposure. Field-pesticide trials were also conducted to determine the compatibility of different pesticide programs with maintaining P. persimilis populations in commercial tomato production, and potentially minimizing the need for chemical suppression of twospotted spider mite.