Location of citrus thrips, Scirtothrips citri, on the ground in blueberries and control with Beauveria bassiana in the San Joaquin Valley of California

Citrus thrips, Scirtothrips citri (Moulton), is a plant-feeding pest most widely recognized for damage caused to citrus and mango. Recently, it has broadened its known host range to become a significant pest of blueberries grown in California’s San Joaquin Valley. Knowledge of this insect’s life cycle coupled with identifying ground locations in blueberry fields has suggested the possibility of using Beauveria bassiana (Balsamo) to aid in field control of pupae in the upper layers of soil as an alternative to traditional pesticides. Laboratory bioassays have determined sites of pupal refuge and the percent infection after exposure to several fungal isolates. The results of thrips ground locations and infection trials in the field will be discussed.