Comparison of the first detection date of fall army worm in areas south of the Yellow River in Baiyin,Gansu Province
By comparing the date and latitude of the initial detection of fall armyworms in areas south of the Yellow River in Baiyin,Gansu Province,we found that as the latitude increased,the onset of fall armyworm was delayed.There was a significant positive correlation between the first detection date of fall armyworm adults and larvae and the number of northern latitudes.On average,when the latitude increased by 1 °N,the onset time of adults and larvae was delayed by 5.2 days and 9.3 days,respectively.In Baiyin City,in the upper reaches of the Yellow River,the invasion of fall armyworm took place 35-43 days,32 days after Tianshui City,and 1 day earlier than Qingyang City and Gannan prefecture.In Baiyin City,situated in the upper reaches of the Yellow River,the onset of fall armyworm took place 35-43 days after Longnan City,32 days after Tianshui City,10-59 days after Qingyang City,and 1 day earlier than that of Gannan Prefecture.When compared to Pingliang City,Guyuan City,Zhongwei City,and Lanzhou City,it showed a delay of 2-20 days,4-7 days,2-29 days,and an advancement of 1 day,respectively.In recent years,the Yellow River valley area has been the first place of fall armyworm occurrence in Baiyin City,followed by the corn fields along the Yellow River irrigation area.
NETL
NSTL
万方数据
