Portal:Animal and Plant Health Inspection Service

“ Variability in treatments, weather conditions, and overall tree health can result in uneven insecticide distribution within a tree and prevent the insecticide from killing all ALB in an infested tree. Also, the insecticide is not effective against the later larval stages that spend most of their time inside the heartwood of the tree where treatment will not reach them. These larvae can continue to grow inside the treated tree, develop, and still emerge as adult beetles. All infested trees must be removed because that is the most effective way to completely eliminate the beetle. ”

“ When does the ALB program use insecticide treatments on trees?When does the ALB program use insecticide treatments on trees? When deciding whether to treat trees with imidacloprid, APHIS and State officials consider several important factors, including environmental and biological issues, the scale of an infestation, recent ALB survey results, and cost. Insecticide treatments are used only on trees that are not known to be infested. The treatment kills beetles or larvae that try to feed on the tree and helps prevent it from becoming infested. ”

“ When do applications take place?When do applications take place? Imidacloprid treatments can be effective against ALB when applied in the spring, early summer, or fall—either before adult beetle emergence or when adults are feeding and laying eggs. ”