Population dynamics of leptinotarsa decemlineata (Coleoptera: Chrysomelidae): Measuring the effects of methyl salicylate and predator recruitment in Potato

Methyl salicylate is an organic compound produced by potato and other plants in response to insect herbivory. In other studies the compound has been shown to be attractive to numerous predatory arthropods. Experiments were conducted in Virginia to evaluate methyl salicylate lures for attracting natural enemies in potato plots to manage populations of Leptinotarsa decemlineata (Say). Abundance of predatory arthropods and L. decemlineata life stages were measured in plots treated with and without 90 day, 5 g slow-release packets of methyl salicylate (95% methyl salicylate [Predalure™]). Mortality of L. decemlineata eggs and small larvae was estimated by calculating the difference in numbers of individuals recruited to subsequent stages using a stage-specific life table approach. Methyl salicylate treatment had no impact on predator recruitment or mortality of L. decemlineata eggs and small larvae, compared with nontreated plots. Cumulative mortality of L. decemlineata ranged from 87.9 - 89.2% in 2010 and from 81.9 - 94.8% in 2011. The dominant arthropod predators observed on potatoes included Hippodamia convergens Guerin-Meneville, Coccinella septempunctata L., and Perillus bioculatus (F.).