A monitoring system and development of ecologically sound treatments for elm leaf beetle

Abstract

Xanthogaleruca luteola damage can be predicted in time to determine if treatment is necessary by determining the percentage of 30 cm branch terminals with ELB eggs. When over 45% of branch terminals have ELB eggs in the week when egg density is at a maximum, treatment is warranted for the first generation; in the second generation, when 30% of branches have eggs. Monitoring degree-days allows sampling and treatments to be scheduled for maximum efficiency and effectiveness. Environmentally acceptable treatments under development include release of the egg parasite Tetrastichus gallerucae, trunk banding with insecticide, and foliar spraying with Bacillus thuringiensis formulations. These methods have been developed primarily for English elm in N and C California. -from Authors