Temporal And Spatial Distribution Of Spodoptera Fugiperda And Its Influencing Factors In Hubei Province

Spodoptera fugiperda is a migratory pest that has invaded China in recent years.This pest has wide range of extensive host plants,strong reproduction and migration ability,and serious damage effect,posing a major threat to China’s food security.Hubei Province is a suitable habitat for FAW,and it is also a transition area for the pest to migrate from the overwintering area in the south of China to the corn planting area in the north.The pest that migrates here from southern China every year not only can colonize here and damage local crops,but also continue to migrate northward and harm northern corn planting areas.The climate conditions,planting time and growth phenology of maize in different regions of the province are different,which may lead to spatiotemporal differences in the population distribution of FAW.Based on the adult trapping data at representative sites in 22 counties and cities in Hubei Province,this paper studied the spatiotemporal distribution characteristics of FAW by statistical analysis,and analyzed the impact of temperature,humidity and host crop planting area data on the spatiotemporal distribution of FAW,and the results are as follows:(1)The statistical analysis of adult trapping data from 22 sites in Hubei Province showed that there were significant spatiotemporal differences in the population of FAW.By dividing the 22 sites into western,central and eastern Hubei,it was found that there was no significant difference between the adult number of central and eastern Hubei,but there was a significant difference between the adult number of central and eastern Hubei.The adult number of western Hubei was relatively low,while the that of central and eastern Hubei was relatively high;The adult number in autumn in the three regions was significantly higher than that in summer,but the time at which the annual peak occurred was different,which was earliest in western,followed by central and eastern Hubei.(2)The linear mixed model analysis of daily average temperature data at 22 points found significant regional and seasonal differences in temperature conditions.The daily average temperature of western Hubei was lower in summer and autumn,while higher in central and eastern Hubei was higher.The daily average temperature of the three regions in summer was higher than that of autumn.Based on the regression analysis of the temperature data in 2020 and the corresponding adult data of FAW,it was found that there was a significant exponential function dependence between the number of adults and the daily average temperature,indicating that the daily average temperature had a significant impact on the number of adults.(3)Based on the linear mixed model analysis of the daily average relative humidity data at 22 sample sites,it was found that there were significant regional and seasonal differences in the humidity conditions among the 22 sample sites.Based on the regression analysis of the relative humidity in 2020 and the corresponding adult data of FAW,it was found that the relative humidity in summer had no significant impact on the number of adults of FAW,while the relative humidity in autumn had a significant impact on the number of adults of FAW.(4)The linear mixed model analysis of the planting area data of host crops at 22 sites showed that the diversity index of host crops had significant spatiotemporal differences.Based on the correlation analysis between the host crop data and the corresponding adult data of FAW in 2020,it was found that the proportion of planting area of corn,peanut,wheat and beans was negatively correlated with the number of adults of FAW in grassland,while the proportion of planting area of Simpson index,cotton and vegetables was positively correlated with the number of adults of FAW in grassland.To sum up,there were significant spatiotemporal differences in the adult data of FAW in the study area,and the temperature and humidity conditions and the host crop diversity index had a significant impact on this spatiotemporal difference.This study is helpful to understand the spatiotemporal distribution characteristics of FAW adults in Hubei Province,and provide basis for the comprehensive prevention and control of FAW in Hubei Province and even in the main corn production areas in northern China.