Study On Biological Learning And Prediction Of Suitable Habitats Of Japanese Pine Scales In Guizhou

The Matsucoccus matsumurae Kuwana(Japanese pine bast scale,PBS)is an important invasive pest of forests in the world.Originally from Japan,it was first discovered in Liaoning in 1942 and then in China's Shandong,Hebei,Jiangsu,Zhejiang,Jilin,Anhui,Shanghai,Guangdong,Sichuan and Shaanxi provinces,to cause great economic loss to our country.It damages the hoet plants by piercing and sucking the nutrients out of the stems and branches.After the host plant is damaged,its branches will bend down and its needles will turn yellow,causing secondary pests and diseases,which severely affect pine growth,and even lead to a large-scale death of the pine forest.Because of the strong concealment of the life cycle and damage symptoms,which is easily confused with fungal diseases,making prevention and control difficult was considered as an offical quarantine forest pest in China before2013.The Matsucoccus matsumurae was first discovered in 2014 in Huichuan District,Zunyi City,Guizhou Province.At present,it has caused the death of 330 hm~2Pinus massoniana plantation,which has caused significant losses to the economic,ecological and social development of Guizhou forestry,and has become an important exotic pest second only to the Bursaphelenchus xylophilus.In order to grasp the life history,living habits and hazard status of the Matsucoccus matsumurae in Guizhou,and formulate scientific control strategies,by using methods of field investigations,morphological identification,regular monitoring of various deveiopment stages,and artificial inoculation,systematic research was conducted on the morphology,biological characteristics and life historyof the Matsucoccus matsumuraes.At the same time,using the maximum entropy model(Maxent),combined with the geographic information system and the known geographical distribution points of PBS in the world and 20 environmental variables,the potential geographic distribution of PBS in Guizhou was predicted.Moreover,based on the results of field investigations,combined with a large amount of literature review,the forest pest risk assessment index system is used to assess the risk of the Matsucoccus matsumuraes in Guizhou province from both qualitative and quantitative aspects.At last,monitoring system construction and control measures of the Matsucoccus matsumuraes in Guizhou Province is proposed.The main findings of this study are as follows:1.The results of biological study show that the morphology and biological characteristics of male and female adults of the new pine pest that have seriously damaged the Pinus massoniana since 2014 in Huichuan District and Suiyang County,conforms to the classification characteristics of the Matsucoccus matsumuraes,as which it wasdefinitely identified.the scale insect is a new record in Guizhou.It occurs2 generations a year in Guizhou,with the first generation from mid-to-late March to mid-to-late October and the second generation from mid-September to mid-to-late May of the following year,overwintering with the second-generation first-instar parasitic nymphs.The offspring are reproduced through sexual reproduction.The hatching rate reached 97.90%;no parthenogenesis is observed.At present,the Japanese pine scale is only found to be harmful to Masson pine in Guizhou.It mainly relies on wind for short-distance natural propagation.It has the characteristics of fast transmission speed and high fatality rate.2.The prediction results of potential geographic distribution show that the suitable areas for Matsucoccus matsumurae in Guizhou are mainly distributed in Tongren,Zunyi,Qiandongnan,Qiannan Prefecture,Guiyang,Anshun and Bijie,With a total area of approximately 141,500 km~2(Table 3).The total area of high and moderately suitable areas is 93,800 km~2,accounting for about 53.3%of the total land area of Guizhou.The current distribution range only accounts for 0.75‰of its highly suitable areas(distribution range is 2 000 hm~2,and highly suitable areas are 26,400km~2).Thus,the pest has high potential to spread to the surrounding area,especially to the northwest area.Central Guizhou,Southeast Guizhou,and northern Guizhou are the concentrated distribution areas of Pinus massoniana in Guizhou Province,which have large area of pure Pinus massoniana plantations.Once the Matsucoccus matsumurae is introduced,it will cause serious losses.Therefore,key monitoring should be carried out in this area,to prevent the introduction of the Matsucoccus matsumurae.3.The resultof the multi-index risk analysis of the Matsucoccus matsumurae show that its comprehensive risk assessment value is 2.57.According to the classification standard,Matsucoccus matsumurae is determined to be a highly dangerous forest pest in Guizhou.Although the Matsucoccus matsumurae is currently only occurring in some parts of Guizhou,it has a strong tendency to spread and pose a great potential threat to the pine forests in Guizhou.