| The Moritziella castaneivora Miyazaki belongs to Aphdoidea and Phylloxeridae. It is a newly reported pest on Castanea crenata and C.mollissimain in China. It harms chestnut on the flowers and fruits and makes them falling off before mature, which leads to large economic damage.To control this pest, we studied on its biological and ecological characters, and the effect of temperature to its growth, the execution of the pesticide and the ability controlled by the natural enemies,etc.The studies yields the following conclusions:1,Studies on the morphological characters and biological characters of Moritziella castaneivora Miyazaki showed that the morphological characters,the representation of its damage,the life behaviors and the rule of its occurrence in different age of its life history.This pest occurs 10 generations more or less a year.It lives through the winter in the basal of the chestnut tree by its grown pest, or in the gap or the back of the trunk and the basal of its bud by its eggs. It begins to move at the last ten-day of April the next year. At Auguest and Septemper, the number of this pest arrives at its fastigium. This pest is obviously superposition, we can find different age of the pest at the same time in the garden.The eggs are always produced in the basal of the chestnut or side face of the chestnut thorns.It lays eggs in a fine and breeze day.The diffuse time concentrates in the first and second nymphae time.2,In the range of 17 degree to 33 degree, the livability,oviposited,life–span of the aging pest in 5 different constant temperature grads are measured. The results indicates that temperature directly influences the livability,oviposited,life–span of the aging pest. The eggs and the first stage larva can hardly survive at 17℃, and its livability gets peak at 25℃.The adults lay eggs at its great number at 25℃, and the higher the temperature is, the earlier it bores. The longevity of the adults becomes shorter as the raise of the temperature.3,The development periods of this pest in 5 different constant temperature grads are measured. At 17℃, it needs 24.53 days to complete the whole generation. And at 33℃, it needs 8.18 days. The regression model of the whole stages is made by the relations between the life course and the growth rates and the temperature.4,With the help of linear regression method, we get the temperature of the development aero in different development stages. The eggs is 14.846℃, the first larva stages is 10.481℃,the second larva stages is 6.7417℃,the third larva stages is 7.7202℃, the forth larva stages is 7.7481℃.The effective accumulated temperature are measured, the eggs is 32.275℃·d, the first larva stages is 21.697℃·d, the second larva stages is30.399℃·d,the third larva stages is30.86℃·d,the forth larva stages is33.943℃·d,the whole generation is194.46℃·d5,The toxicity test of several insecticides against this pest in and out laboratory are measured. We find the 1%WeiBaoEC is the best insecticide. Otherwise, actualizing integrated management is an effective way to control this pest.6,The functional response of Scymuns hoffmanni Weise to Moritziella castaneivora Miyazaki was studied through laboratory experiments. Scymuns hoffmanni Weise had high efficiency to control Moritziella castaneivora Miyazaki. The selectivity experiment in predation of Scymuns hoffmanni Weise showed that the ladybird beetle preferred egg ,not adult of Moritziella castaneivora Miyazaki。The predatory counts of Moritziella castaneivora Miyazaki egg at different stage of Scymuns hoffmanni Weise were determined at the same time. Laboratory studies showed that the functional responses of 1-4instar larvae and adult of Scymuns hoffmanni Weise to eggs of Moritziella castaneivora Miyazaki belong to HollingⅡtype and educed their models, respectively, indicating that the ladybird in larger instar has higher searching and predatory abilities. The relationship between searching efficiency(E)and density of the adult(P) is described by Hassell&Varley′s model E=QP-m as E=0.572P-1.6791(r=0.9883).The results of disturbing responses experiment showed that the density of Scymuns hoffmanni Weise had effect on predation of itself.
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