Preliminary Investigation On Diversity And Ecological Niche Of Rubber Borer In Hainan

The rubber borer is the general ter m for the beetle-like beetle har med by the trunk of rubber of the Coleoptera(Coleoptera),mainly distributed in the southern provinces of China.The rubber borer have strong adaptability,amazing reproductive capacity and take cover of harm,so they are outbreak easily.In recent years,the rubber borer has occurred to har m rubber trees and take great losses to the rubber industry in China.Hainan is one of the main producing areas of natural rubber in China.monitoring and control of rubber borer is great significance for rubber industrial in China.In this paper,the species of rubber borer in five regions of Hainan were investigated,and the related studies on the diversity,spatial distribution type,and ecological niche of rubber borer were investigated.The results are as follows:1.There are 20 species of rubber borer were collected fro m five locations in Hainan:Chengmai,Qiongzhon,Danzhou,Wanning,and Wuzhishan by three methods:Anato mical trunk,light inducement,and aggregation phero mone to trap rubber borer.There are 2 families and 14 genera;among them,there are 10 genera of Buntingidae and 4 genera of Buntingidae.Xylosandrus discolor and Xyleborus affinis are the dominant species distributed in rubber plantation in Hainan Province.The two species are Euplatypus parallelus and Euwallacea denticulus.Hypothenemus eruditus is a subopti mal species.According to the analysis of the healthy rubber tree,it is concluded that there are differences between the dominant species of rubber borer distributed within the rubber plantation and the pioneer species of rubber.Pioneer species are four-spotted chestnuts,Euwallacea interjectus,Euwallacea fornicatus,Xyleborinus andrewesii,Cyclorhipidion sp.,secondary species.They are Euphatypus parallelus,Crossotarsus externedentatus,Dinoplatypus cavus,Beaverium insulindicus,and Xyleborinus artestriatus.2.The species diversity of rubber borer in Hainan was analysed by the richness index(S),the Simpson ecological dominance(D),the Shannon-Wiener diversity index(H),and the Pielou evenness index(J).The results showed that the ranking of richness(S)index was:Danzhou>Wuzhishan>Chengmai>Qiongzhon>Wanning,Danzhou had the highest species richness,Wanning had the lowest richness,and rubber borer Simpson ecological dominance(D).The order of size is:Chengmai?Wanning?Danzhou? Wuzhishan?Qiongzhon;Shannon-Wiener infor mation diversity index(H)is ranked as Danzhou?Chengmai>Wuzhishan>Wanning>Qiongzhong;Pielou evenness The ranking of the index(J)is Wanning>Chengmai>Danzhou>Qiongzhon>Wuzhishan.3.The spatial distribution types of rubber borer in Hainan were tested by the aggregation index test,Iwao regression analysis test and Taylor's power law test.Three test results showed that rubber borer is aggregated distribution in Hainan rubber plantation.4.The ecological niche theory was used to study the five dominant rubber borer on the rubber tree,and the results showed that:the ecological niche breadth of the five species was overall low,and the ecological niche breadth of Euwallacea interjectus was the largest,with a value of 0.4658.The ecological niche overlap index of Xyleborinus andrewesii and other four dominant species was the highest on rubber tree,and the spatial ecological niche overlap of Euwallacea interjectus and Cyclorhipidion sp.is smaller than other species.The ecological similarity coefficient is high overall,and the ecological similarity index of Euwallacea denticulus and Euwallacea fornicatus is 0.7516 and it is highest among all species.The competition coefficient is high among Euwallacea denticulus,Euwallacea interjectus,Euwallacea fornicatus and so they compete strongly each other.The competition coefficient is low Xyleborinus andrewesii and Cyclorhipidion sp.so that indicating their feeding site is differential.The range of utilization of resources of five rubber borer is relatively small,and the damage sites is concentrated at 0-3 m.5.The effects of trapping rubber borer was analysised by light trapping and aggregation pheromone trapping,two methods results showed that the population density of the rubber borer was the largest at the height of lm than other height significantly;The population of rubber borer is the largest of Danzhou,which is higher than other areas significantly.There were 17 species rubber borer trapped by aggregation pheromone and 8 species by LED lights,and the number smaller.The effect of trapping rubber borer by aggregation pheromone was better than light trapping.