Why the yew tree (Taxus baccata) is not attacked by insects

Abstract In recent years, the yew tree has attracted considerable attention due to the isolation from it of the important antitumour drug Taxol ® . The fact that the wood is not attacked by woodworm and its needles are attacked by very few insects has so far neither been examined nor exploited. Extracts of Taxus baccata have strong antifeedant activity against storage pests Tribolium confusum , Trogoderma granarium and Sitophilus granarius . Nine pure compounds were isolated from the extract and very strong antifeedant activity was exhibited by 10-deacetylbaccatin III and 10-deacetylbaccatin V, which most probably are responsible for the activity and the resistance to insects.