Imidacloprid

Imidacloprid is a systemic neonicotinoid insecticide that acts on the insect nervous system by binding to nicotinic acetylcholine receptors, causing paralysis and death. It is one of the most widely used insecticides in tree care, effective against a broad range of sucking insects (aphids, adelgids, scales), some boring insects, and leaf-feeding beetles.

In arboriculture, imidacloprid is commonly applied as a soil drench around the root zone or as a trunk injection. Soil drenches are the simplest application method but may take weeks to reach effective canopy concentrations. Trunk injection provides faster distribution. The product provides extended residual protection, often lasting an entire growing season from a single application.

The use of imidacloprid and other neonicotinoids has become controversial due to concerns about pollinator impacts. Research has shown that imidacloprid can be present in pollen and nectar of treated flowering trees at levels that may harm bees and other pollinators. Best practices include avoiding treatment of trees during bloom, not treating trees that are attractive to pollinators when alternatives exist, and considering alternative products like emamectin benzoate for species like ash where pollinator exposure is lower.