我国草地贪夜蛾年发生世代区划分

为明确草地贪夜蛾在我国不同地区的年发生世代数,为提高其预测预报和综合防治水平提供科学依据,本研究采用不同恒温(20、24、28、32、36℃)条件,以玉米苗为幼虫食物测定了草地贪夜蛾不同发育阶段及全世代的发育历期,计算出草地贪夜蛾不同发育阶段、全世代发育起点温度和有效积温。在此基础上,结合1985年-2014年30年全国605个气象站点的气象数据预测了草地贪夜蛾在我国不同地区的年发生世代数,并利用地理信息系统对其年发生世代区进行了划分。结果表明:草地贪夜蛾卵、1~6龄幼虫、蛹、雌成虫和雄成虫的发育起点温度分别为11.20、9.63、13.03、12.88、11.09、13.04、10.73、13.90、13.98℃和16.68℃,有效积温分别为41.32、41.32、18.71、28.23、45.87、60.33、55.90、90.97、166.86日·度和121.90日·度;全世代发育起点温度为12.6℃,有效积温为584.0日·度。根据全国不同地区气象数据推测草地贪夜蛾在我国的理论年平均发生世代数在0~7.41代之间,总体上发生世代数随纬度和海拔的升高而减少。我国1月份12.6℃等温线以南地区全年最低温度高于草地贪夜蛾发育起点温度,为周年繁殖区域,主要位于云南南部(全年发生世代数最高可超过5代)、广西南部、广东中部以南、福建东南部(全年世代数最高可超过6代)、台湾大部(全年世代数最高可超过7代)以及海南省全境(全年可发生7代以上)。江南和江淮迁飞过渡区主要为4~5代区和3~4代区。黄淮海及北方重点防范区主要为2~3代区和1~2代区,部分为3~4代区。

Annual generation numbers prediction and division of fall armyworm, Spodoptera frugiperda in China

In order to investigate the annual generation numbers of fall armyworm in different regions of China,and provide scientific basis for fall armyworm forecast and integrated control,the developmental durations of each developmental stage and whole generation of fall armyworm were determined at constant temperatures(20,24,28,32,36℃),and the effective accumulated temperature and the developmental threshold temperature were calculated.And then the annual generation numbers of fall armyworm in different regions of China were predicted based on the 30 years(1985-2014)meteorological data of 605 meteorological stations.Then the whole country was divided into eight regions according to the annual generation numbers of fall armyworm using geographic information system.The developmental threshold temperatures of eggs,1st-6th instar larvae,pupae,female and male adults were 11.20,9.63,13.03,12.88,11.09,13.04,10.73,13.90,13.98 and 16.68℃,respectively,and the effective accumulated temperatures were 41.32,41.32,18.71,28.23,45.87,60.33,55.90,90.97,166.86 d·℃and 121.90 d·℃,respectively.The developmental threshold temperature and effective accumulated temperature of the whole generation were 12.6℃and 584.0 d·℃,respectively.The theoretical average annual generation numbers of fall armyworm ranged from 0 to 7.41.The theoretical average annual generation numbers decreased with the increase of latitude and altitude.In January,the annual minimum temperature in the south of 12.6℃isotherm was above 12.6℃,which was higher than the developmental threshold temperature of fall armyworm,and the fall armyworm could develop normally all year round.These areas include southern of Yunnan(annual generation numbers can exceed five generations at most),southern of Guangxi,south of Guangdong,southeast of Fujian(annual generation numbers can exceed six generations at most),most of Taiwan(annual generation numbers can exceed seven generations at most)and all of Hainan province(more than seven generation numbers throughout the year).The fall armyworm could occur four to five generations and three to four generations in migration transition zones of Jiangnan and Jianghuai areas.In Huang-huai-hai and the key prevention areas(northern China),the fall armyworm could occur two to three or one to two generations in most areas,and three to four generations in some areas.