是否形成虫瘿及虫瘿的位置、形态等是蚜虫生物学的重要特征。

Forming galls or not and the position, morphology and structure of galls are the important characteristic of aphids.

方法：通过探讨虫瘿发育规律及其发育过程单宁酸含量的变化。

Method: The regulation of development and tannin amount during whole growing stage were studied.

蚜虫通常群居于植物虫瘿内（由于昆虫产卵寄生引起的异常发育部分）。

The aphid colonies grow inside galls, abnormal outgrowths on plants.