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采用气相色谱法测定了不同时期麦红吸浆虫Sitodiplosismosellana (Gehin)幼虫脂肪酸的变化。结果表明 :幼虫脂肪酸组分有 1 0～ 1 6种 ,其中主要以棕榈酸 (C1 6:0 )、油酸 (C1 8:1 )和亚油酸 (C1 8:2 ) 3种组分为主 ,占全部脂肪酸总量的 95 %以上 ;其次是硬脂酸 (C1 8:0 )含量较高 ,约占 2 %～ 3 .5 % ;其它组分脂肪酸含量很少 ,均在 1 %以下。从 5月中下旬麦红吸浆虫幼虫离穗入土进入越夏至翌年 4月化蛹羽化前 ,脂肪酸组分表现了由少到多的变化趋势。越夏、越冬幼虫及越冬后未进入活动状态的圆茧其脂肪酸组分中不含花生酸 (C2 0 :0 ) ,而且饱和脂肪酸含量明显少于越冬后进入活动状态的幼虫和麦穗幼虫 ;而越冬后进入活动状态的幼虫和麦穗幼虫脂肪酸组分中含有一定量的花生酸 ,不饱和脂肪酸含量明显少于越夏、越冬幼虫及越冬后未进入活动状态的圆茧 ,故花生酸的有无及饱和脂肪酸与不饱和脂肪酸含量的比例变化可作为判断麦红吸浆虫幼虫活动状态 ,特别是滞育不同深度的生化指标之一
The fatty acid contents of larvae of Sitodiplosismosellana (Gehin) at different stages were determined by gas chromatography. The results showed that there were 10 ~ 16 kinds of fatty acid components in larvae, which were mainly composed of 3 components of palmitic acid (C1 6: 0), oleic acid (C1 8: 1) and linoleic acid (C1 8: 2) Main, accounting for more than 95% of total fatty acids; followed by stearic acid (C1 8: 0) content is high, accounting for about 2% to 3.5%; other components of fatty acid content is very small, are less than 1% . From mid-to-late May midgut larvae from the spike into the soil into the summer before the next year in April pupation eclosion, fatty acid components showed a trend from less to more. The overwintering, overwintering larvae and the cocoon which did not enter the active state after overwintering did not contain arachidic acid (C2 0: 0) in the fatty acid component, but also the content of saturated fatty acid was obviously less than that of the larva and the ear larva which entered the active state after the winter. However, the larvae and ears larvae that entered into the active state after overwintering contained a certain amount of arachidic acid, the contents of unsaturated fatty acids were significantly less than those of the overwintering, overwintering larvae and the cocoon which did not enter the active state after the winter, The change of the ratio of saturated fatty acid to unsaturated fatty acid content may be used as one of the biochemical indexes to determine the activity status of M. imageri larvae, especially diapause at different depths