四种草蛉生活史和习性的研究

在室内饲养了四种草蛉,观察其生活史和各发育阶段的历期。结合田间消长调查,认为四种草蛉在山东一年主要发生四代,成虫寿命和产卵期长,世代重叠现象严重,且系兼性滞育越冬,部分个体发育至四代以上。对草蛉食棉蚜及棉铃虫卵量作了观察。叶色草蛉是山东麦田、棉田的优势种,其次是中华草蛉。在棉田内自然蛉量以7月中旬至8月上旬最多,应注意保护和繁殖释放,以增加棉田蛉量;这是减轻和防治伏蚜和三代棉铃虫为害的重要措施之一。草蛉是棉蚜、棉铃虫的重要天敌。叶色草蛉(Chrysopa phyllochromaWesmacl)、中华草蛉(C.sinica Tjeder)、大草蛉(C.SeptempunctataWesmael)和丽草蛉(C.formosa Brauer)是我省的主要种类。1976—1978年于临清、泰安等县对其生活史和田间发生情况等作了观察,现整理如下。

STUDIES ON THE LIFE HISTORIES AND BIONOMICS OF FOUR SPECIES OF GREEN LACEWINGS

In this paper the life histories and the predacious capacities of four species of green lacewings,Chrysopa phyllochroma Wesmael,C. septempunctata Wesmael,C. sinica Tjeder and C. formosa Brauer,are detailed.According to our observation they have four generations each year in the Shantung Province.Because thier female have longer longevity of life and periods of oviposition and the phenomena of alternate generations are very common,there is the probability that some of them appear over four generations.The green lacewings overwinter in th eadult of over-wintering type and the rest of three species in propupasin cocoons.All these four species can prey on cotton aphids and eggs of cotton bollworms,and are important natural enemies for the two cotton insect pests in our province.Among them,C. phyllochroma Wesmael is the dominant species in wheat and cotton fields.Thier natural population occurs in greet numbers from the middle of June to the begining of August in cotton fields.It is the proper time of biologically control for controlling "the summer aphids" and the third generation of the cotton bollworms.