Potential pesticides for control of a recently introduced ambrosia beetle (Euwallacea sp.) in southern California

摘要: Polyphagous shot hole borer (PSHB) has recently invaded southern California. This beetle attacks more than 200 host tree species, including avocado (Persea americana Mill.) and many important native, urban landscape nursery stock trees sycamore (Platanus racemosa Nutt.), box elder (Acer negundo L.). The beetle, along with its associated fungi, causes branch dieback mortality in a large variety of species. Due to the severity impact PSHB, short-term management tools must include chemical control options for industry private landowners protect trees. We assessed effectiveness systemic contact insecticides PSHB laboratory tests using fresh-cut castor bean (Ricinus communis L.) branches. Castor was chosen because, as weedy it is widely available, preferred beetles. conducted field mature, weedy, infested field-grown bean. also surveyed coral (Erythrina corallodendron an established residential landscape. For bean, activity lowest plants treated bifenthrin, imidacloprid dinotefuran. Bifenthrin most effective insecticide reducing gallery formation branches experiments cut Dinotefuran variable trials. Fenpropathrin, clothianidin orange oil extracts did not differ from untreated controls formation. Based on these results, bifenthrin were selected further testing combination fungicides PSHB.