DEFENSE AGAINST PHYTOPHAGIC INSECTS BY AR OMATIC PLANTS ALLELOCHEMICALS

Some ethnobotanical observations show that aromatic plants are used as traditional protectants of leguminosae seeds to avoid beetles attacks in southwestern France. The efficiency of this method was tested in l aboratory. Aromatic plants present a double insecticidal effect : by d irect toxicity on adults and also inhibition of the reproduction. The most efficient plants belong to Labiatae family. The insecticidal effe ct of water extracted and residual botanicals were tested. Several all elochemicals, especially monoterpenes and polyphenols, synthetized by the plants' secondary metabolism, are involved in this toxicity. The t oxic ecochemical activity of these compounds could be considered as al ternative or complementary method to classical pesticides for a better insect pest management.