Study On Suitable Area Analysis And Rapid Detection Technology Of The Hessian Fly,Mayetiola Destructor(Say)

Mayetiola destructor（Say）is an important wheat pest in the world,which has been listed as an entry quarantine pest by several countries,and it is also an important invasive pest in China.At present,it is only distributed in Xinjiang.Under the background of global warming,the change of its potential habitat area is not clear.In addition,there is a lack of simple and rapid diagnostic tools in field or port quarantine.In this study,Max Ent and Arc GIS software were used to predict the potential suitable areas of M.destructor in China and the world at the present and the next 50 years,based on the current and future climate scenarios of RCP 2.6（minimum greenhouse gas emissions）,RCP 4.5（moderate greenhouse gas emissions）,and RCP 8.5（highest greenhouse gas emissions）,and the climate factors affecting their distribution were analyzed.Besides,a rapid visual detection technique of loop-mediated isothermal amplification（LAMP）was developed.The main research results are as follows:（1）Prediction of the distributions of M.destructor（Say）,under climatic change in China:Under the current climate conditions,the suitable distribution areas of the M.destructor in China were 25°N-48°N,81°E-123°E,with an area of 5.46×10⁶km²,accounting for 56.64%of the total area of China,mainly concentrated in the central and eastern regions.The total high suitable distribution area is approximately 9.63×10⁵km²,accounting for 9.99%of the total national area,which is mainly in northern Xinjiang,Hunan,Hubei,Chongqing,Guizhou,Sichuan,Jiangxi,Anhui,Jiangsu,Zhejiang,Shanghai,Henan,Fujian,Taiwan and Shaanxi.The potential suitable area of M.destructor in Xinjiang was 77.12×10⁴km²,accounting for approximately 46.46%of Xinjiang’s total area.The high suitable area accounted for approximately 19.62%of the total suitable areas in Xinjiang and is mainly located in Ili Prefecture,Bortala Prefecture,Tacheng Prefecture,Karamay City,Altay Prefecture,and Changji Prefecture.With the rising global temperatures,except for the high suitable areas under the RCP 8.5 scenario,most potential geographic distribution areas would expand in the future.（2）Prediction of the distributions of M.destructor（Say）,under climatic change in the world:Under the current climate conditions,the suitable distribution area of M.destructor is approximately 4.96×10⁷km²,accounting for 33.61%of the global total land area,and mainly in 25°N-60°N、55°W-125°W and 10°W-123°E.The high suitable area is 2.10×10⁷km²,accounting for 13.69%,which is mainly distributed in North America,Europe,West Asia and northern Africa.With the increase of global temperature,the potential suitable area of M.destructor would expanded and shifted northward gradually.（3）The important environmental factors affecting M.destructor:According to the Jackknife results of Max Ent,9 climate factors were selected out of 67 climate factors,which had important affects on the geographical distribution of M.destructor,including the maximum temperature in November（tmax-11）,minimum temperature in February（tmin-2）,precipitation in March（prec-3）,precipitation seasonality（bio-15）,precipitation in November（prec-11）,maximum temperature in June（tmax-6）,precipitation of the wettest month（bio-13）,temperature annual range（bio-7）and mean diurnal range（bio-2）.In which,tamx-11,tmin-2,prec-3 and bio15 are the four key factors affecting its distribution.（4）A LAMP method for the rapid detection of M.destructor:The LAMP primer set based on the mitochondrial cytochrome oxidase I（COI）gene had good specificity and a sensitivity of 1.0×10^-3ngμL^-1for DNA concentration detection,which is 1000 times that of conventional PCR.The amplification was completed in 50 min at a constant temperature（64±1°C）,and in combination with the toothpick DNA extraction method,the field test was conducted in only 52 min.This technology requires only a portable thermostatic heating device and necessary reagents for precise visual detection,which is simple to operate,and can be performed by non-specialists,facilitating field inspection and outbreak monitoring.In conclusion,this study evaluated and screened the main environmental factors affecting the geographical distribution of M.destructor,predicted the potential suitable areas of M.destructor under the current and future climate scenarios,provideing an important reference and empirical basis for management of the M.destructor in the future.The LAMP rapid detection technology of M.destructor was developed to provide technical support for field monitoring and port inspection,and was of great significance for effectively preventing the introduction and spread of M.destructor.