内蒙古草原蝗虫大暴发的气象条件及预警

Meteorological Conditions and Prewarning of Grasshopper Plagues in Inner Mongolia

通过分析40年来内蒙古草原蝗虫大暴发的气象条件,发现:夏、秋季干旱和冬暖,蝗虫越冬卵的成活率高,冬季积雪对蝗卵具有保护作用,晚春的大幅度降温会导致蝗虫死亡率较高;春雨多和升温平稳能提高蝗卵孵化率;蝗卵胚胎发育期出现强降温,可明显降低蝗虫的出土率;蝗蝻期怕寒潮和强霜冻,一旦进入4龄期以后,蝗虫便具有了自主躲避外界不利条件的能力;越冬卵、胚胎发育阶段及蝗蝻3龄期以前的气象条件,对蝗虫的大暴发有重要的影响,可据此对蝗灾进行预警。

The meteorological conditions for grasshopper disasters from 1980 to 2004 in Inner Mongolia grasslands are studied. Results indicate that droughts in summer and fall and winter warming are advantageous to the survival of the overwintering grasshopper eggs, and the snow cover in winter can protect the eggs, but heavy snow at the end of spring would be fatal to grasshoppers. Rich rainfall in spring and gradually increasing temperature are favorable to the hatchability of grasshopper eggs. The emergence rate of nymphs can be reduced evidently when temperature drops strongly during the embryo and growth stages of eggs as nymphs cannot endure cold waves and heavy frost. After entering the fourth larval instar, grasshoppers begin to have the ability to avoid adverse conditions. The meteorological conditions before the growth stage of overwintering eggs and embryos and the third instar of nymphs have significant influence on the large-scale outburst of grasshoppers, and thus can be used as good indicators in the early warning of grasshopper disasters.