The insect resistance of a tree is influenced by several factors,such as the distribution and quantity of stone cell and crystals in cortex and phloem,the content of cellulose,the thickness and composition of cork layer, etc.

• 皮层和韧皮部中的石细胞，结晶体的分布、数量，纤维素的多少、排列状况，木栓层厚度、组成，后含物均能影响树本的抗虫性能。