Studies on insect community characteristics and time dynamics of juju be tree in greenhouse

Based on the method of fuzzy clustering,the characteristic indexes and the time dynamic of jujube insect community in greenhouse were studied.The results show that the control times of main insect pests may be divided into four p hases.The phases of February,May and June are the key phases of chemical control,during which the insect community is hardly steady,the quantity of superior species Contarinia sp.and Tetranychus fruncatus becomes larger,causing thes e pest insects to break out easily.Conversely,in order to protect the nature enemies and give full play to their action,the methods of agriculture,physics and biology must be used to control the insect pests and in the rest time of a year.