Study On Insect Community And The Distribution Of Dominant Species In Mountainous Grassland Of Wugong Mountain

Wugong mountain nature reserve,belong to the northern section of luoxiao mountains range,stretching more than 120 km,about 970 square kilometers,is the important ecological and climatic crisscross area in China,with unique climate,rich resources of insects and insect diversity.But due to a variety of reasons,such as society,geography and history of wugong mountain nature.The reserve of insect resources have not been system investigation and researc h,there is very little systematic investigation of the insects and report.Theref ore,wugong mountain nature reserve of insect resources investigation,the dive rsity of system research,and insects geographical fauna analysis,protection an d utilization of biodiversity in the region is of great significance.This study aims to build basic data for the rational exploitation of insect resources and provide reference for control of insect pests in Wugongshan mountain meadows.The insect species at the mountain meadows were systemically collected in six typical habitats,in which the altitudes range from 1593 meters to 1855 meters,using the method of sampling “Z” pattern by sweeping nets during 2013-2015.The characteristics of the insect community in different habitats were analyzed based on the community indicators including index of dominance,abundance,diversity and evenness.A total of 7895 insect specimens were collected.These specimens are categorized into nine orders in which Coleoptera,Hemiptera and Diptera are the dominant taxa.The number of insects in these three orders comprised 96.19% of the total specimens.The changes of each community index were similar in different years.These indexes reached the highest or lowest value in July.The analysis of Jaccard similarity index showed that the similarity coefficient between the mixed area(alt.1657 m)and the southeastern slope near the Launching Tower(alt.1855 m)was 0.2499,indicating an extremely dissimilar level.The similarity coefficients between the other four sample plots ranged from 0.3020 to 0.4207 were moderately similar.The similarity coefficient between the northwestern slope and southeastern slope near the Launching Tower were only 0.3050 although they shared the same higher elevation.However,their similarities to other plots(similarity coefficient ranging from 0.2499 to 0.3230)were lower than the similarities between the other four plots(similarity coefficient ranging from 0.3597 to 0.4207).The insect species in the meadow are abundant in Wugongshan mountains.Its insect species diversity had an obviously seasonal pattern.The insect community structure in the hilly meadows were relatively stable,and it was influenced by local climate,habitat type of host plants,altitude and slope aspects,which resulted in that each habitat had its own unique species distribution pattern.Geometridae from Wugongshan Nature Reserve of Jiangxi Province collection and identification for the first time and its fauna composition is analyzed.A total of48 genera were collected and 48 insect species were indentified,The dominance of the species was Odontopera bilinearia,Crypsicometa homoema.The species in the Palaearctic-Orientalendemic and Oriental Region species appear to be predominant,accounting for 83.33% and 14.58% of the total species in the world fauna.A total of9 kinds of fauna in China,which accounted for over 15% of the total species of 4species,accounting for 77.08% of the total of the species in the mountain.The stink bug,Urochela distincta Distant(Hemiptera: Urostylidae),is an endemic species to China,its population with a habit of cluster migration and aestivation,and outbrook in Wugong Mountain and Xiangutan Scenic Area of Jiangxi Province in recent years.In order to early warn and monitor to outbreak of its population in relevant nature reserve and scenic spots in China,the geographical distribution of the insect was predicted based on its recorded distribution data in Jiangxi,Hunan and Guizhou provinces and 20 variables related with occurring environment by using Max Ent and DIVA-GIS.The results showed that the main environment variables affected the distribution of U.distincta including: precipitation of driest month,altitude,mean diurnal range,precipitation of warmest quarter,min temperature of coldest month,isothermality,mean temperature of driest quarter and mean temperature of wettest quarter.Among them,the precipitation of driest month and altitude were the most important factors affecting the distribution of U.distincta,with the contribution rate of 64.9% and 19.5%.The most suitable areas for the bug belonged to the regions of the altitude by 700-1500 m where received precipitation by 25-130 mm in the driest month,mainly distributed in central China and part areas in southern China and the eastern regions in southwest China,such as Luoxiao mountains handover of Jiangxi and Hunan,Wuyi mountains in Jiangxi and Fujian border,and Wuling mountains was located in Chongqing,Hunan,Guizhou and Hube.The unsuitable area includes northern China,western China,some parts of central China and a few regions of southern China.