吉林省亚洲玉米螟的发生规律

通过对玉米秸秆垛中越冬代亚洲玉米螟的调查数据分析,明确了吉林省中部地区(公主岭)越冬代玉米螟蛹的始见期、始盛期、高峰期、盛末期和终见期.通过对田间系统调查数据分析,明确了一、二代玉米螟卵的始见期、始盛期、高峰期、盛末期和终见期.一代玉米螟卵的孵化率达90%以上,卵很少被寄生和捕食,一代幼虫化蛹率为89%～94%.二代玉米螟的田间整个落卵期卵粒赤眼蜂寄生率达70%,卵被捕食和脱落很少,在9月12日左右二代老龄幼虫占92.7%,未见二代幼虫化蛹.研究表明吉林省中部地区玉米螟已由每年发生1.5代转变为每年发生2代.并对导致世代数变化的可能原因进行了讨论.

The occurrence of the Asian corn borer in Jilin Province

Through analysis of the investigation data of the Asian corn borer,Ostrinia furnacalis (Guenée) (ACB), overwintering generation in the piles of maize stalks in Gongzhuling City, Jilin Province, a conclusion is reached on the appearing stage, initial peak stage, peak stage, ending peak stage and disappearing stage during the pupation of the overwintering generation. Through analysis to the systematic investigation data in field, it is determined that the appearing stage, initial peak stage, peak stage, ending peak stage and disappearing stage of the first and second generation eggs. The percentage of hatching is more than 90%, and the parasitism and predatoriness percentage of the eggs is relatively low in the first generation . The pupation rate is from 89% to 94% in the first generation. The parasitization rate of egg masses by Trichogramma spp. is 70% in the second generation ACB. There are less eggs were predated and dropped in the period. The percentage of mature larvae is 92.7% and no pupae are observed in the second generation ACB when dissecting the corn stalks in the middle of September. The occurrence of the ACB have changed from one and a half generations into two generations in the middle region of Jilin Province.