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 history and the lack of above ground pupation sites on blueberries bushes 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 been conducted to determine percent infection after exposure to several fungal isolates. The results of these infection trials will be discussed as well as a comparison of the efficacy of the isolates.