Study on Population Dynamics of Aphis citricola and Community Structure of Natural Enemy in Different Types of Apple Orchard in ZhaoTong City

Population dynamics of Aphis citricola Van der Goot and the community structure of natural enemy in the different apple orchards in ZhaoTong City were investigated.According to the management mode into three types: each type of orchard select 5 tree of 12 branches of new shoots of 20 leaves investigation,survey of predators using tree visual and sweep and luring investigation.Population density of Aphis citricola conventional management is higher than the organic demonstration garden and chemical control orchard,chemical control orchard population density minimum.Natural enemy community compositions of three orchards had obvious difference.The results showed that,the population density was the highest in the routine management apple garden;the natural enemy species and individual number of the organic demonstration garden were higher than those of the conventional management garden and chemical control garden.Natural enemy species and individual numbers of organic demonstration garden are greater than routine management garden and chemical control orchard,the ratio of up to 1.304.Organic demonstration garden management mode can better protection from predators,population density of Aphis citricola has also been best control.