小地老虎(Agvotis ypsilon Rott.)食性杂,是旱地作物和果木苗圃最凶狠的地下害虫,尤其第一代幼虫危害最烈,因此及早做好预测,提高防治效果,是非常重要的。(一)发生特点经过两年的观察,小地老虎在我县一年可发生(?)代,以3月下旬至4月上旬第一代幼虫危害最为猖獗。该代成虫于2月上、中旬,当日平均气温达8℃以上时开始出现,2月下旬至3月上旬出现第一次发蛾高峰,3月中旬出现第二次发蛾高峰。第一次蛾量约占当代总蛾 Agrotis ypsilon Rott., Is the most fierce underground pest of dryland crops and fruit trees nurseries. In particular, the first generation larvae are most endangered. Therefore, it is very important to make early prediction and improve the control effect. (I) Occurrence After two years of observation, small Tigers can occur in our county for one year, with the first generation larva damaging most frequently from late March to early April. The adult worm began to appear in the upper mid-February and the average temperature of the day reached above 8 ° C in February. The first peak occurred in late February and early March, and the second peak occurred in mid-March. The first moth is about the total moth of the present age