Study On The Relationship Between The Pest Of Prosodes Dilaticollis Motsch And Grassland Change In Southern Mountain Grassland Of Manas Based On Spatial Information Technology

Prosodes dilaticollis Motsch,belonging to Tenebrionidae of Coleoptera,mainly distributed in arid grassland of Xinjiang,Inner Mongolia,Gansu,Ningxia,fed on the roots of grass,stems,leaves,is a kind of underground pest living in grasslands.The outbreak of the pest,biting the grassland,causing the problem of " competition between insects and livestock ",and finally causes a series of ecological problems such as grassland bare,grassland degradation,soil erosion.However,Prosodes dilaticollis Motsch is also a part of the ecosystem.In the case of unknown disaster mechanism,the large-scale use of pesticides will not only pollute the environment,but also destroy the balance of the original ecology system.It is very important for grassland department based on space information technology to explore the coupling relationship between pest occurrence and grassland degradation,analyze the interaction relationship between pest occurrence and environmental factors such as vegetation,climate,land cover change,summarize the disaster mechanism of Prosodes dilaticollis Motsch in Xinjiang desert grassland so as to provide scientific and effective monitoring,prediction of Prosodes dilaticollis Motsch.In summary,these aspects of research were carried out in this paper:(1)By summarizing and analyzing the historical research materials of Prosodes dilaticollis Motsch these conclusions were found: 1)The pest is caused by the mixture of six species of tenebrionid beetles,such as Acanthopanax,Nitraria,pipiens,arenaria and Euonymus.2)The outbreak of the beetle is closely related to the overload of livestock carrying capacity,soil erosion and biodiversity reduction,which is a comprehensive ecological problem.3)Liu Fangzheng put forward the term "Prosodes dilaticollis Motsch" that takes into account the regional characteristics of the occurrence of the pest and the scientific nature that the insect is only a desert population of Tenebrionidae.Therefore,it is reasonable to use the name of "Prosodes dilaticollis Motsch".(2)Based on Vegetation coverage retrieved from remote sensing,the relationship between insect density and grassland change was quantitatively analyzed by linear trend method,single-factor variance analysis,kriking interpolation and overlay analysis.These conclusions were found: the pest of Prosodes dilaticollis Motsch had no direct relationship with grassland degradation.The increase of population density is an indicator of grassland desertification.After grassland degradation,the bare land with low vegetation coverage(Such as the ecotone of agriculture and animal husbandry,alluvial land of seasonal river)turns green in spring and in order to meet the energy requirement of pupation,the old larvae need to eat a large amount of forage and cause the “Insect pest”.(3)Based on climate data,digital elevation model(DEM),land cover data,the relationship between pest outbreak and the environment factors was analyzed.The findings are as follows: 1)The grassland ecosystem of semi-desert grassland has the typical characteristics of vulnerability and sensitivity of the arid grassland ecosystem.Grassland degradation/restoration occurs repeatedly and precipitation is the most important factor affecting grassland degradation/restoration 2)The suitable area for the beetle is the places where altitude is 800～1000m,slope is 0～5°,aspect is sunny slope.3)The warm and wet years with more precipitation,longer sunshine hours and higher average temperature may be conducive to the outbreak of the bettel.