Spatial Distribution of the Main Pests on the Alpine Brassica oleracea L.in Zhouning County

We investigated the population dynamics and spatial distribution of main pests on alpine Brassica oleracea L.in Zhouning county from April to June,2013.The results showed that Plutella xyllostella,Myzus persicae and Phyllotreta striolata are the main pests in the vegetable field.Meanwhile,aggregation indexes and Iwao regression methods were used to explore the spatial distribution pattern on the alpine Brassica oleracea L..Our results showed that the aggregation index of P.xyllostellaand M.persicae distribution in the five different fields are I>0,M*/m>1,CA >0,C>1,K>0,suggesting that there has an aggregative spatial distribution of P.striolatain the field of 1,2,3,and uniform in the field of 4and 5.