甘肃河西走廊甜菜象发生规律的研究

以甜菜象虫的优势种甜菜象为主要对象，重点研究了它的发生规律和为害特点，结果表明：甜菜象的生活史为一年一代，以成虫和少数幼虫与蛹在土中越冬，翌年４月上、中旬当气温达１０℃左右时开始出土，４月下旬至６月上旬为发生盛期。５月下旬至６月上旬为产卵盛期。６月至８月中旬未为幼虫盛发期，７月中旬至８月下旬为蛹盛期，８月下旬第一代成虫盛发。

Studies on the Pattern of Occurrence of Bothynoderes punctiventris Germar in Hexi Corridor, Gansu Province

This study was carried out in the sugar beet weevils infested districts of Hexi corri-dor in Gansu province in 1987～1989.The authors made a thorough investigation a thorough investigation and study on the pattern of occurrence regarding Bothynoderes punctiventris Germar which was a predominant species a -mong 19 species of sugar beet weevils found in sugar beet cultivation area. the results showed that Bothynoderes punctiventris Germar had only one generation a year in Hexi corridor, Gansu province.A great majority of this pest hibernated with the adults; some pupae and larvae which descend into deeper soil in the last October or early November may also hibernate.The adults emerged from soil in the curred from the last ten days of April to the first ten days of June.The peak period of laying was in last ten days of May through first ten days of June. The peak period of larvae occurred from the last ten days of June up to the last period of the second ten days of August.The peak period of pupae occurred from the second ten days of July to last ten days of August, and a great number of the adults emerged from pupae were found in the last ten days of August.