Short communication. The antifeedant activity of natural plant products towards the larvae of Spodoptera littoralis

Worms are becoming difficult pests to control since many insecticides are now forbidden and the present alternatives are insufficiently effective. Antifeedants of plant origin may have potential against such pests. In this work, several diterpenoids, flavones and coumarins extracted from plants were assayed as antifeedant agents against Spodoptera littoralis larvae. Among these compounds, four diterpenes (eriocephalin, salviacoccin, aethiopinone and oxocandesalvone) and four coumarins (oxypeucedanin, xanthotoxin, isoimperatorin and prangol) showed significant activity, whereas all the flavones tested were inactive. Some aspects of the structure-activity relationships of these compounds are briefly discussed. Additional key words: coumarins, diterpenes, flavones, higher plants, secondary metabolites.