Effect Of Weeds On Insect Community Characteristics In Tea Garden

Weeds are important components of tea garden ecosystem,which has a complex regulatory effect on insect community in tea garden.Based on the systematic investigation of weed species and insect community in the tea garden of Tai’an,the dynamics and characteristics of insect community in natural weed tea shed and regularly weeding tea shed were analyzed by using ecological principles and methods,and the relationship between the occurrence of pests and natural enemies and the growth of weeds was discussed by using the optimal time sequence division method,and finally,the influence of weeds,not only on tea pests and natural enemy population but also on the diversity and stability of insect community in tea garden,was comprehensively evaluated.The purpose is to provide theoretical support for the optimization of tea garden management measures and the green control of tea pests.The results are as follows:1.Through the investigation of weed species and insect community in tea garden,it was found that there were 34 species of weeds in tea garden of Taishan,belonging to 10 orders and15 families.In the tea shed of weed group,a total of 110,947 insects were collected,belonging to 255 species in 91 families of 2 classes,11 orders,and in the grassless group,102,586 insects were collected,belonging to 204 species in 83 families of 2 classes,10 orders.Weeds increased the species and quantity of insects in tea gardens,mainly in Lepidoptera and Coleoptera.2.The relative abundance of main pests and natural enemies in tea garden was analyzed.The main pests in the two groups were sucking insects.Specifically,in the tea shed of weed group,the proportion of leafhoppers and whiteflies was 54.83% and 22.57% respectively,and in the grassless group,leafhopper pests accounted for 49.75% and whitefly pests accounted for 28.89%.In terms of natural enemies,the ratio of predatory pests in the weed tea shed is67.79%,and the ratio of parasitic natural enemies is 36.21%.The ratio of predatory natural enemies in the grassless group is 73.40%,and that of parasitic natural enemies is 24.93%.The composition of pests in the two groups of tea sheds is similar,and the population of parasitic natural enemies in the weed group is more complicated.3.The dominant species of pests and natural enemies were analyzed according to the dominance index.During the whole tea growing period,there were 9 dominant species of tea pests and 15 dominant species of natural enemies in weed tea shed.There are 10 dominant species of tea pests and 10 dominant species of natural enemies in grassless tea shed.The unique dominant species in the weed group are Carcelia sp.,Phanerotoma planifrons,Sclerodermus guani,Mymaridae sp.,and Menemerus confuses.4.Through the analysis of the population dynamics of pests and natural enemies in the tea shad of weed group and grassless group,it was found that the growth of weeds significantly increased the population of Apolygus lucorμm.Increase the overall occurrence of Dialeurodes citri,Kolla paulula,Matsumurasca onukii and Scirtothrips dorsalis.Weeds can significantly promote the natural enemy population of spiders and ladybugs,which has seasonal characteristics,but they have no significant effect on syrphids.5.The community characteristics such as species richness,ecological dominance,diversity and evenness of insect population in tea garden were analyzed.Weeds improved the diversity and stability of insect community in tea garden.The temporal pattern of pests and natural enemies in weed tea shed group and grassless tea shed group was divided into four periods by using the optimal segmentation method of time series.The development of dominant pests in the two groups of tea sheds is basically the same.It is considered that weeds in tea garden promote the occurrence of pest population.The first period(April25-June 21)is the damage period of overwintering pests,during which Aleurocanthus spiniferus is the main pest,and Scirtothrips dorsalis,Apolygus lucorμm and leafhoppers coexist;The second period(June 28th-August 31st)is the concurrent period of three kinds of pests,and Kolla paulula,Phlogotettix cyclops and Scirtothrips dorsalis have become the main pests;The third period(September 6-October 4)is the occurrence period of Dialeurodes citri,which is serious;The fourth period(October 11th-December 7th)is the damage period of the Singapora shinshana and Matsumurasca onukii.Tea planting should stay away from Moraceae,Ligustrum lucidum,Prunus persica.