Study on Apriona germari Damaging the Clones of Sect.Leuce

The paper discusses an investigation on damage degree of 34 clones of sect. leuce of five-year plantation caused by Apriona germari . Four statistical variables were selected,i.e.insect density (head/tree),insect tree percentage (%),infection index and borer damage duration (year). Use the method of vague cluster analysis——making analysis by taking Euclidean Distance as Group Average Method of cluster statistical variable. The conclusion shows that the damage degree of 34 clones by A.germari has remarkable difference,or different clone has showen obvious different resistance to A.germari. According to Cluster Redigree Figure,the 34 clones can be divided into four typers. T23,T12,T32 and other nine clones as fourth type,insect tree percentage 7%～25%,infection index 11.1～29.5,insect density1.0 head/tree which called resistance clones to infectation.