Preliminary Study on Aggregation and Dispersion Tendencies of Natural Population of Green Tobacco Aphid

The analysis method of spatial pattern was applied to study the aggregation and dispersion tendencies of green bobacco aphid Myzus persicae (Sulzer) among whole and vertical strata of tobacco plant.From transplanting to ripe,which are the periods of tobacco plant growth,the aggregation and dispersion tendencies of green tobacco aphid among upper,middle and lower leaves were traited by using Mont Lloyds method and combining the model of Iwao (m-m) and improved Iwaos model.The results show that green tobacco aphid has two aggregative peaks which are in the late June and mid-July,respectively.The aggregation and dispersion tendencies of green tobacco aphid are some different among different parts of tobacco plant,as the result of natural selection and adaptation.The green tobacco aphid appears aggregative pattern among whole tobacco plant and upper,middle and lower leaves.The analysis can help the rational control of green tobacco aphid.