河南北部稻蛀茎夜蛾的发生规律研究初报

随着全球气候变暖,昆虫分布及越冬地域也在发生变化。稻蛀茎夜蛾Sesamia inferens(Walker)的越冬北限在20世纪80年代被认为不过北纬34°线,近年发现该虫在更北的黄淮海夏玉米-小麦轮作种植区新乡市(北纬35°)发生为害,为该种植模式下发生的新害虫。为了准确监测,科学、有效地制定该害虫的防治对策,本研究对河南北部地区稻蛀茎夜蛾的发生为害规律及生活史进行了初步调查。结果表明:稻蛀茎夜蛾可以在小麦-玉米轮作的条件下顺利完成生活史,其中在河南新乡该虫为害穗期玉米并顺利越冬的事实是首次报道。应用灯光监测并结合田间幼虫调查发现,当地稻蛀茎夜蛾一年发生3代。越冬代幼虫化蛹后在4月中下旬开始羽化,羽化的成虫在小麦或早春玉米上产卵,第1代幼虫主要为害春玉米和小麦,6月中旬第1代成虫开始羽化飞往夏玉米田内产卵,幼虫主要为害夏玉米幼苗。第2代幼虫化蛹后于8月初开始羽化形成第2代成虫,产卵孵化后的幼虫主要钻蛀夏玉米穗和茎秆,9月下旬幼虫陆续沿茎秆钻入玉米残桩基部越冬。综合调查结果,绘制了河南北部地区稻蛀茎夜蛾的年生活史表。

Preliminary study on the occurrence of pink stem borer, Sesamia inferens (Walker) (Lepidoptera: Noctuidae) in northern Henan Province

Global warming and climate change are likely to trigger changes in geographical distribution and overwintering region of insect pests. The northern boundary of overwintering for pink stem borer, Sesamia inferens (Walker) (Lepidoptera: Noctuidae) was at 34° north latitude in 1980s. Recently, occurrence and damage of S. inferens on summer corn seedlings has been first observed in wheat-maize rotation region of Xinxiang (35° north latitude), northern Henan Province. In order to develop a sound forecasting and management program in summer corn region of China, population dynamics and life history of S. inferens were investigated in Xinxiang from 2014 to 2015. The results indicated that S. inferens could finish its life history and damage on ears of summer corn in Xinxiang, which was the first report about its northern boundary in China. Light traps and field surveys showed there were three generations per year for S. inferens in this area. The overwintering larvae pupated and emerged in mid to late April, and then female adults laid eggs on winter wheat and spring corn. Larvae of the first generation damaged winter wheat and spring corn in late May and early June and mature larvae of this generation pupated and emerged after mid-June. The moths of the first generation transferred into summer corn field and oviposited in corn seedling for continuous life cycle. Larvae of the second generation damaged seedling after mid-July. S. inferens larvae of the third generation (overwintering generation) damaged the stem and ear in summer corn field and drilled into the root of corn stalk for overwintering in late September. An annual life history table for the S. inferens in northern Henan Province was drawn based on these observed data.