Insecticidal activity of compounds from Ailanthus altissima against Spodoptera littoralis larvae.

We determined the efficacy of Ailanthus altissima extracts, obtained using solvents of various polarity, in terms of acute and chronic toxicity, antifeedant efficacy and larval growth inhibition of Spodoptera littoralis. Different efficacy was found for individual fractions, in terms of both acute and chronic toxicity, as well as antifeedant efficacy and growth inhibition of S. littoralis larvae. Fractions 1 and 2, obtained at the beginning of the separation period, were the only ones to cause significant chronic toxicity accompanied by larval growth inhibition. A major proportion of tocopherol isomers were detected in these fractions. On the contrary, fractions 5 and 6 caused acute toxicity, associated with significant antifeedant efficacy and related strong growth inhibition of S. littoralis larvae. Five major quassinoids (Ailanthone, Chaparrinone, Glaucarubinone, 13(18)-Dehydroglaucarubinone and Shinjulactone H) were detected in fraction 5, which showed the greatest efficacy in terms of acute toxicity and feed intake inhibition of S. littoralis. Methanol extracts or active substances obtained from A. altissima leaves can be recommended for the development of new botanical insecticides targeted against some phytophagous larval species of butterfly pests.