中国西北地区油菜茎象甲的消长与防治策略

油菜茎象甲(Ceuthorhynchus asper Roel) 是中国西北地区油菜的主要害虫，一年发生一代，以成虫越冬。发生规律因地区、生态条件或当地小气候不同而差异较大，不同油菜种植区及其所处地理海拔不同，其消长规律也不相同；同一地区阳坡地带发生较早，其次是平川和阴坡地。在冬油菜区，油菜茎象甲成虫于2月至3月上中旬陆续出土活动，2月中旬至3月下旬产卵为害，其成虫均有越夏越冬习性。在春油菜区，油菜茎象甲成虫于4月下旬至5月上中旬出土活动，5月中下旬交尾产卵，其蛹羽化为成虫后因气候冷凉大多不经过越夏，而是活动一段时期后直接越冬。对茎象甲的防治应掌握其活动消长规律，抓好关键时期采用化学和农业防治措施综合控制。

Fluctuation and control strategy of rapeseed stem weevil in Northwestern China

Rapeseed stem weevil (Ceuthorrhynchus asper Roel.) is the main rapeseed pest in Northwestern China.It occurs one generation each year with adult overwintering.The fluctuation pattern varied in different areas with different ecological conditions or local climates.For example,planting region of rapeseed and elevation affected its active regularity.And the stem weevil occurred earlier in sloping field toward the sunlight than that in plain or shady field.In winter rapeseed regions of the Northwestern China,rapeseed stem weevil adults came out of soil from early February to mid-March.Their egging period lasted from mid-February to late March.Then the adults went oversummering and overwintering.In spring rapeseed region,adults came out from late April to mid-May.Then they mated and laid eggs until the end of May.After a period of activity, most of them hibernated directly without oversummering for cool climate after pupas becoming adults.According to the study,chemical application and agricultural manipulation at key periods could efficiently control rapeseed stem weevil.