咸宁地区桔全爪螨与天敌种群动态的初步研究

咸宁地区桔全爪螨与天敌种群动态的初步研究甘宗义，王盛桃（湖北省农科院果树茶叶研究所，武昌４３０２０９）ＰｏｐｕｌａｔｉｏｎＤｙｎａｍｉｃｓｏｆＣｉｔｒｕｓＲｃｄＭｉｔｅ（ＰａｎｏｎｙｃｈｕｓｃｉｔｒｉＭｃＧ．）ａｎｄＩｔｓＮａｔｕｒａｌＥｎｅｍｉｅｓ...

Population Dynamics of Citrus Rcd Mite(Panonychus citri McG.)and Its Natural Enemies in Xianning Area.

ecause of the stable ecological environment in the orange garden,the population develop- ments of Citrus red mite and its enemies coincide with Leslie Pattern:H(t 1)=5.019224H(t)/[1 49. 525954P(t)],p(t 1)=2.681411P(t)/[1 3.651781P(t)/H(t)]. Analysis of the populational dynamics shows that:(1)controlling effect of natural enemies(Stethorus punc- tillum,etc.)on Citrus red mites is usually enlarged with the mite.'s population rising in the or- chard.If the density of the mite's enemies amounts to 0. 05 0.08 head per leaf,development of the injurious mite can be controlled.(2)The ratio between beneficial and injurious insects,which is changing with their populatlonal densities,restricts the populational trends of the mite's enemies,so the ratio cannot be simply used as an index to control the injurious mites.(3) Extraordinarily low population of the mite is not beneficial to the development of its ene- mies.Spraying pesticide too early or too much may lead to great damage from the mite,and unsuitable pesticide using will bring about the same result.