The ratio of hosted branch below 1 year old was more than 95%,1 to 2 year old was 5%,Kerria lacca hardly hosted on branch over 2 year old.

• 紫胶蚧选择在1年生及其以下枝条上固定取食的比率达95%25以上,1年生以上2年生以下枝条上固定取食的比率为5%25,基本不在2年生及其以上枝条上固定取食。