Evaluating Methyl Salicylate Lures on Natural Enemies, Pests and Meristem Damage in Red Maple Fields1

Abstract Red maple seedlings transplanted in spring must grow vertically quickly and insecticides are applied to prevent meristem damage. While sprays have achieved desired results, sustainable options are being sought. Methyl salicylate (MeSA) is a common herbivore-induced plant volatile that is available as a commercial lure to attract natural enemies into farms. We conducted a 2-year field study to determine if MeSA-treated plots had more natural enemies, fewer insect pests, and less meristem damage. The only natural enemy detected in statistically higher abundance within MeSA plots was the minute pirate bug ( Orius spp.), a predator of thrips (Thripidae) and aphids (Aphidae). However, this increase in abundance was only higher during the end of the second-year trial. Abundance of aphid alates was statistically lower in MeSA blocks 2 weeks after application. No other pests were significantly lower in MeSA-treated than control plots. Meristem damage in MeSA blocks was lower overall in the first year, and for the first 3 weeks in the second-year trial. While MeSA was associated with significantly less meristem damage, the mechanism was not clear from arthropod samples and potential reasons are discussed. Species used in this study: red maple ( Acer rubrum L.); minute pirate bug ( Orius spp.). Chemicals used in this study: Methyl salicylate (Predalure).