川东川西玉米钻心虫种群动态及其防治对策

POPULATION DYNAMICS AND CONTROL STRATEGY OF FIVE SPECIES OF CORN BORER IN EAST AND WEST SICHUAN

玉米钻心虫是四川玉米上的主要害虫,发生普遍.为害严重。通过系统调查,明确了四川有玉米螟、大螟、高梁条螟、桃蛀螟和粟灰螟5种。玉米螟在川东占72.3～78.9％,大螟在川西约占60％,为优势种。这两种虫在成都、绵竹均一年发生3代,万县、达县为3～4代。根据川东立体气候特点,可划分为四个垂直分布生态区,第一生态区高梁条螟占58.9％,第四生态区粟灰螟占27.8％,第二、三生态区玉米螟分别为94.3％及98.7％,占绝对优势。本文还探讨了螟害程度与玉米生长势、播期、天敌、地势等因素的关系,并分区提出了防治对策。

The corn borer is a cosmopolitau and seriously injured insect pests of corn in Sichuan. An investigation of corn borers was made and found five species: Asiatic corn borer (Ostrinia furnacalis Guenee), pink stem borer (Sesamia inferens Walk), stripe borer (Proceras venosatus Walker), Grey millet borer (Chilo infuscatellus Snellen) and peach moth (Dichocrocis punctife-ralis Guenee). The first species is the dorinant species in East Sichuan (72.3-78.9%), while the second one is dormant in West Sichuan (60%). They have three generations a year in Chengdu and Mianzhu, three to four generations a year in Wanxian and Daxian. The East Sichuan can be divided ecologically into four vertical distribution belts. Striped sorghum bcrer reaches a population about 58.9% in the first belt, grey millet borer is about 27.8% in the fourth belt. Asiatic corn bcrer is as high as 94.3% in the second and 98.7% in the third ecological belts. This paper also explains the relationship between the injury of the moth larva and corn growing, sowing time, natural enemies, terrainand so on. Besides, it deals with the controlling strategy too.