徐州地区甜菜夜蛾发生规律的初步研究

Preliminary study on the occurrence pattern of Spodoptera exigua in Xuzhou area

甜菜夜蛾近几年在徐州地区重发生频率增加。在该地1a发生5代。在当4月份5cm土温稳定通过13℃时,黑光灯下始见越冬代蛾,10月份5cm土温稳定通过10.5℃时,终见末代蛾。从二、三代开始出现世代重叠。成虫多产卵于叶片反面。幼虫主要取食叶片,以二至四代幼虫为害最重,多数老熟幼虫入5cm表土化蛹。卵、幼虫、蛹的发育历期分别为2.6～4.2d、8.2～12.5d、5.6～8.7d。夏季降水量、种植业结构、寄主长势、杂草密度及外地虫源的迁入是影响其发生量的重要条件。搞好测报,运用多种农业防治手段,合理开展化学防治是主要治理对策。

The outbreak frequency of Spodoptera exigua increased in recent years in Xuzhou area. There are five generations in a year. The overwintering generation moth emerges when the soil temperature under 5 cm ground increases steadily up to 13℃ in April, and the last disappears when the soil temperature decreases steadily to 10.5℃ in October. Important factors affecting occurrence pattern of Spodoptera exigua were connected with precipitation in summer, structure of crop cultivation, host plants, weeds and immigration of moth from other areas. The main strategies for the pest management were discussed in this paper.