Effects Of Different Cover Grass Planting On Arthropod Community Structure And Diversity In Mango Orchard

In recent years,woodland orchards have received extensive attention for ecologically regulating pests and diseases in orchards by planting grass.In order to evaluate the impact of the grass planted in the Hainan mango economic forest land on the protection of fruit gardens and arthropod communities,Arachis pintoi cv.Reyan and Axonopus compressus(Sw.)were systematically studied in the mango woodland of Ledong Li Autonomous County,Hainan Province from 2018 to 2019.P.Beauv.,Stylosanthes guianensis cv.Reyan,Desmodium intortum(Mill.)Urb.,Allium tuberosum Rottler,and natural grass.The growth of 6 different grasses planted in mango woodland and the structure and diversity of arthropod community.The main findings are as follows:1.Evaluate and clarify the types of grass suitable for mango economic woodland planting.The growth of Arachis pintoi cv.Reyan,Axonopus compressus(Sw.)P.Beauv.,Stylosanthes guianensis cv.Reyan,Allium tuberosum Rottler,natural grass can It grows normally in mango orchards,but there are differences in growth volume,coverage effect and management difficulty.Among them,Axonopus compressus(Sw.)P.Beauv.was sealed in 90 days after transplanting,and the plant height and stem length were maintained at 35 cm and 40 cm respectively after sealing.Stylosanthes guianensis cv.Reyan requires a sealing time of about 3 months,and then there is no significant change in plant height and stem length.Arachis pintoi cv.Reyan needs about 120 days to complete the seal.After the seal is closed,it will continue to grow prostrate and the plant height should be kept at around 14 cm.Allium tuberosum Rottler does not continue to increase after 90 days after transplanting,when the coverage reaches the maximum.Desmodium intortum(Mill.)Urb.had no significant increase in plant height and stem length after transplanting for 30 days,and the maximum coverage was only 22.50%,which could not continue normal growth.The mango orchard has natural grass coverage in the field of more than 80%,with an average plant height of about 50 cm.Overall,Arachis pintoi cv.Reyan,Axonopus compressus(Sw.)P.Beauv.,and Stylanthanthes guianensiscv.Reyan are suitable for planting in woodland.Natural grass and Allium tuberosum Rottler are more suitable than Arachis pintoi cv.Reyan,Axonopus compressus(Sw.)P.Beauv.and Stylosanthes guianensis cv.Reyan are difficult to manage,and both are host hosts for pests such as leaf gall mosquitoes and Bemisia tabaci.Desmodium intortum(Mill.)Urb.cannot grow normally in the mango orchard habitat.2.Clarified the impact of Axonopus compressus(Sw.)P.Beauv.,Arachis pintoi cv.Reyan,Stylosanthes guianensis cv.Reyan and other grass plantings on the diversity of arthropod communities.The results showed that the Axonopus compressus(Sw.)P.Beauv.,Arachis pintoi cv.Reyan,and Stylosanthes guianensis cv.Reyan habitats had about twice the number of arthropod species in the mango orchard,and the number of individuals in each of the three grass habitats.It is 3 times,4 times,and 8 times that of clear farming habitats.The species diversity index and community stability are higher than clear farming habitats,showing higher biodiversity.Similar results have been shown for natural enemy subcommunities.In terms of pest sub-communities,the number of individuals is lower than that of clearing habitat.The main natural enemy community structure of two mango orchards,spider and lacewing,was analyzed.The number of individual natural enemies in the three grass habitats was higher than that in the clearing habitat.The temporal dynamics of the diversity index of the spider community also showed an overall higher result than the clearing habitat.For the main pests in the mango orchard,the three grass habitats inhibited the outbreak of Thrips thrips population to varying degrees.Comprehensive analysis shows that the planting of three kinds of raw grass has effectively increased the population of spiders and lacewings,enriched the diversity of spider communities,and effectively suppressed the outbreak of thrips.In the similarity of natural enemies subcommunities of three habitats,Arachis pintoi cv.Reyan and Axonopus compressus(Sw.)P.Beauv.have the highest degree of similarity,followed by Stylosanthes guianensis cv.Reyan and Arachis pintoi cv.Reyan The similarities between the natural enemies in the habitats,the clearing habitats and the three grass habitats are the lowest,indicating that the three grass habitats have similarities in the protection of natural enemies.In the pollinating arthropod community in the flowering period,the number of pollinating insect species in the three grass habitats is similar to that in the clearing habitat,but the three individual grass habitats are about twice as many in the number of individuals.The diversity index and evenness index are also higher than the clearing habitat,and the opposite trend is shown in the dominant concentration index.It is comprehensively shown that the three grass habitats can effectively increase the number of individual pollinating insects in the mango orchard and help pollinate during the flowering period.Combined with the above comprehensive analysis,it is shown that planting Axonopus compressus(Sw.)P.Beauv.,Arachis pintoi cv.Reyan,and Stylosanthes guianensis cv.Reyan in mango orchards is beneficial to enhance the diversity of arthropod communities in mango orchards,and uses habitat changes to reduce pests in mango orchards.The number of the population is an effective pest ecological control measure.