The cause of death in overwintering larvae of two persimmon stem pests, Euzophera batangensis and Synanthedon tenuis

Abstract

Euzophera batangensis Caradja and Synanthedon tenuis (Butler) cause serious damages in persimmon stems. I examine the causes of death in overwinter larvae. In the persimmon trees, dead larvae with white fungi were found frequently. In raring test, although two parasite wasps emerged from E. batangensis larvae, no parasite insects emerged from S. tenuis larvae. Dead larvae with white fungi were found in both species under raring condition. Hatch ratio of E. batangensis was lower than S. tenuis. The difference of parasitism between two stem pests correspond to the tendency of actual specie that injures persimmon stems in spring season.