STUDY ON THE SPATIAL PATTERN OF COCOON OF NEODIPRION XIANGYUNICUS

This paper deals with the spatial pattern of cocoon of Neödiprion xiangyunicus in the forest of Pinus yunnanesis.It was found that cocoons were distributed in the soil under crown projection.The pattern is an aggregated distribution.The fundamental unit is a single individual in the inte-rnal,internal inferor and outside layer of soil under crown projection.In the middle layer,the value of mean crowding for the distribution of the number of individuals per basic component is higher,the relative degree of aggregation in the distribution of basic component at low population densi-ties is the highest,and it decreases with the increase of population density.It is an aggregated distribution in all directions,the population density in the Orient is the highest,but it's lowest in the North,the degree of aggre-gation in the North is the highest,but it's lowest in the South.And in intertree,the pupal colonies are double colonies,the area of the small colony is about 10m2 with 5 trees of P.yunnanensis and the area of big one is about 30m2 with 15 trees.The small colony distributed uniformly among the bigger one,and the intertree spatial pattern of cocoon is random.