Persistence in bioassays and field trials of Beauveria bassiana mycoinsecticides against overwintering spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), egg masses

The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), is an invasive planthopper and significant agricultural pest in the United States. Current management relies heavily on insecticides, with limited options for organic or biological control. This study evaluated the overwintering survivability of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) spores on lanternfly egg masses to assess the feasibility of winter and spring, preemergence applications during vine dormancy. Laboratory bioassays suggested treatments of commercially available B. bassiana to spotted lanternfly egg masses resulted in infection of newly eclosed neonates. The optimal timing of spray applications on egg masses was approximately 2 wk before emergence. However, infection was also observed in newly emerged nymphs when treatments were applied even 20 wk before insect hatch. Treatments 20 wk before hatch significantly reduced the viability of conidial residues with wettable powder formulations exhibiting higher germination rates than oil-based formulations. These findings highlight the influence of environmental conditions on fungal spore persistence and underscore the potential for refining formulations and application timing to enhance biological control of spotted lanternfly. Two field trials demonstrated the applicability of mycoinsecticide treatments to overwintering spotted lanternfly egg masses. Both field trials demonstrated infection of hatching nymphs at levels greater than those observed in laboratory bioassays. This management approach would provide growers with a viable, low-toxicity, and Organic Materials Review Institute approved solution for managing spotted lanternfly months to weeks before the predicted hatch of spotted lanternfly.