Background Leopard moth, Zeuzera pyrina L., is a key pest of walnut trees in arid and dry areas. It severely damages walnut tree gardens with limitations on irrigation water in the growing season. This study was conducted to compare the efficacy of trunk injections of three systemic insecticides: imidacloprid, oxydemeton-methyl, thiamethoxam and a complete fertilizer, Nutreeno® against the leopard moth. Trunk injection was done by drilling. The walnut annual shoots of 60 cm in length were sampled from four directions of the treated and control trees in 4 months after treatments. Results The results showed that all treatments including the insecticides and the complete fertilizer at higher concentrations had acceptable efficacy on the leopard moth, and thiamethoxam was the best treatment. Conclusions Trunk injections by neonicotinoid insecticides and Nutreeno can be a safer control method against leopard moth larvae in old walnut trees around residential areas.