Occurrence Dynamics And Control Technology Of Empoasca Onukiitn Tea Production Region In Shaanxi Province

The green leafhopper, Empoasca onukii Matsuda is one of major tea pest insects harmingtea plant in Shaanxi. In this paper, the population dynamics of E. onukii in three tea varietiesand in different layers were investigated, the difference of insect resistance and the followingeffect of spider to E. onukii in three tea varieties were studied. The control effect of3plantpesticides on E. onukii in field efficacy trial was conducted, one plant pesticide with explicitdosages to control the green leafhopper effectively and also, do little impact to the naturalenemy spiders was screened out. The overground pests and natural enemies in the tea gardenin Xixiang, Shaanxi Province were surveyed. The results are as follows:1. The occurrence regularity of adults and nymphs of E. onukii in each tea varieties issingle-peak type, the population quantity increased rapidly from midmonth of July, the annualpopulation of E. onukii reached the peak at the end of July. Further distribution analysis of thepopulation of E. onukii on three kinds of tea varieties showed that the small green leafhopperdistribute more at upper layer than at middle and under layers.2. Resistances to the green leafhopper of three tea varieties differ significantly, theFuding and Ziyang varieties possess higher resistance than Nanjiang variety.3. The population quantity of E. onukii and spiders were positively correlated in Ziyang(R=0.716, P＜0.001), Fuding (R=0.476, P=0.007) and Nanjiang varieties (R=0.652, P＜0.001). Spiders have obvious following effect to the small green leafhopper.4. The control effect of0.6%matrine AS at the dosage of6.3g/hm2is more sustainableand effective against E. onukii Matsuda compared with the use of7.5%rotenone EC at thedosage of67.5g/hm2and1.5%pyrethrins WE at the dosage of27g/hm2. Further researchfound that the use of0.6%matrine AS at the dosage of13.5g/hm2,6.75g/hm2have almostthe same control effects as the use of2.5%bifenthrin SC at the dosage of18.75g/hm2againstE. onukii Matsuda. The recommended usage in fields of0.6%matrine AS is6.75~13.5g/hm2.5. There are134species in the tea garden in Xixiang, Shaanxi Province, among them,66species are pest,64species in37families in6orders belong to Insecta, and2species in2families in1order belong to Arachnida. There were58species of natural enemies resources, among which31species in15families in8orders are in Insecta and27species in10familiesin1order are in Arachnida.10species of neutral insects from3class6families in Insectawere recorded. This work is expected to provide information for comprehensive treatment ofpest and also the utilization of natural enemies in Shaanxi tea region.