Abstract:

According to chemical analysis and bioassay of one-year needles of the damaged and undamaged Pinus tabulaeformis Carr.and larvae of Dendrolimus spectabilis Butler fed on these needles,it was found that the chemical components in the needles of damaged pine had caused regarded growth compared with undamaged pine.The results shows that:(1) total amino acids and most amino acids declined in quantity;(2) the concentrations of soluble sugar,crude fat,alkaloid and ratio of total sugar to total amino acids all increased;(3) there were conspicuous changes in fatty acid and phenolics.(4) weights of the larvae fed on needles of damaged trees were lighter than undamaged trees;and (5) mortality of larvae fed on these needles was 19.2% higher than those fed on leaves of undamaged trees.Delayed induced resistance of Pinus tabulaeformis Carr.to Dendrolimus spectabilis Butler lasted for half a year at least.

Key words: Pinus tabulaeformis Carr. Dendrolimus spectabilis Butler, Induced chemical defense, Delayed induced resistance