IPM helps control elm leaf beetle

The elm leaf beetle, first discovered in California in the 1920s, quickly became one of the state's major urban tree pests. In the past 15 years, monitoring methods have become integral to the design of the Integrated Pest Management program for the elm leaf beetle (ELB). A sampling protocol has been developed that can successfully predict ELB damage based on the presence or absence of egg clusters. A monitoring program based on this sampling technique may allow managers to direct control efforts to only those trees requiring treatment, thus avoiding unnecessary environmental and economic costs. Chemical insecticides are still a temporary solution to the problem, but increasing concern for human and environmental health has stimulated the pursuit of nonchemical approaches. Releases of egg parasitoids have been largely unsuccessful over the past 12 years. An effort is currently under way in Sacramento to improve the Integrated Pest Management program based on monitoring, spot treatments with injected chemical insecticides, foliar application of Bacillus thuringiensis and the release of a new strain of egg parasitoid from Granada, Spain.