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菜粉蝶以幼虫为害十字花科蔬菜,如大白菜、萝卜、花椰菜、甘蓝、西兰花及油菜等,给蔬菜生产造成了严重为害。 一、发生规律 菜粉蝶在河北省一年发生4～5代,以蛹在菜田附近的墙壁、篱笆、风障、树干等处及在砖石、土块和杂草、残枝落叶间越冬。第二年3月下旬越冬代成虫盛发,5～6月份为当年第一次幼虫严重为害时期。7月、8月由于高温多雨及天敌的影响,虫口数量大减。9月上旬前后气候转凉,虫口数量又逐渐上升,9月上中旬形成全年为害的第二次高峰。
Cabbage butterfly larvae cruciferous vegetables, such as cabbage, radish, broccoli, cabbage, broccoli and rape, etc., to the vegetable production caused serious damage. First, the occurrence of law Cabbage butterfly occurred in Hebei Province for 4 to 5 generations a year in order to pupa in the vegetable fields near the walls, fences, wind barriers, trunk, etc., and in the masonry, clods and weeds, stumps and wintering . The second year in late March overwintering adult Cheng Sheng, 5 to June for the first time the larvae seriously damaged period. July and August Due to the effects of hot, rainy weather and natural enemies, the number of insect population dropped sharply. Before and after the first ten days of September, the climate turned cooler and the number of insects increased gradually. In the middle of September, the second peak hit the whole year.