Emamectin Benzoate

Emamectin benzoate is a semi-synthetic insecticide derived from abamectin, a natural compound produced by the soil bacterium Streptomyces avermitilis. It works by enhancing the effects of the neurotransmitter GABA, causing irreversible paralysis in target insects. In tree care, it has become the treatment of choice for protecting ash trees from emerald ash borer (EAB).

The product is administered exclusively by trunk injection, where it is distributed through the xylem to the canopy. Research has consistently shown that emamectin benzoate provides the highest level of EAB control among available insecticides, with protection lasting two to three years from a single treatment. It is also effective against other lepidopteran and coleopteran pests including caterpillars, borers, and beetles.

Emamectin benzoate has several advantages over other systemic insecticides for borer management. It provides longer residual activity than imidacloprid, it does not move through the soil (reducing environmental exposure), and it is not present in pollen or nectar in meaningful amounts, making it safer for pollinators. The primary limitation is cost, as both the product and the required trunk injection service are more expensive than soil drench alternatives. For valuable ash trees in EAB-affected areas, the investment in emamectin benzoate treatment is typically the most reliable protection strategy.