麦红吸浆虫滞育发生和解除过程中总脂和甘油三酯含量变化

【目的】脂类与昆虫滞育密切相关。本研究旨在明确麦红吸浆虫Sitodiplosis mosellana (Géhin)滞育过程中脂类物质含量的变化规律，探讨麦红吸浆虫滞育与脂类物质变化的关系。【方法】采用香兰素硫酸显色法测定了2008年5月－2010年1月不同时间陕西杨凌养虫圃内麦红吸浆虫滞育前、滞育期及滞育解除后幼虫和蛹体内总脂和甘油三酯含量。【结果】 滞育前幼虫总脂和甘油三酯含量分别为378.12和291.67 μg/mg，显著高于整个滞育期（P<0.05）。滞育年周期中，冬季总脂和甘油三酯含量最高，翌年1月结茧幼虫二者含量分别为335.29 和275.72 μg/mg，显著高于其他季节（P<0.05）；整个滞育期间，裸露幼虫和结茧幼虫总脂和甘油三酯随季节变化趋势相同，但同期结茧幼虫含量高于裸露幼虫；滞育当年与第2年同期幼虫总脂和甘油三酯含量差异不显著（P>0.05）。滞育解除后，总脂和甘油三酯含量随着幼虫的发育和变态逐渐降低，其中中蛹和后蛹显著低于活动幼虫（P<0.05）。【结论】麦红吸浆虫滞育不同时期幼虫及蛹总脂和甘油三酯含量存在明显差异，其滞育与脂类物质的含量密切相关。

Changes of total lipid and triglyceride contents in pre-diapause,diapause and post-diapause larvae and pupae of Sitodiplosis mosellana (Diptera: Cecidomyiidae)

【Aim】 Lipids play important roles in insect diapause. Our study aimed to ascertain the change law of lipid content in diapause of Sitodiplosis mosellana (Géhin) and explore the relationship between diapause and lipids in S. mosellana. 【Methods】 Vanillin-sulfuric acid colorimetry was used to analyze the total lipid and triglyceride contents in pre-diapause, diapause and post-diapause larvae and different stage pupae of S. mosellana in a field insectary in Yangling, Shaanxi during May 2008 to January 2010. 【Results】 The contents of total lipids and triglyceride in pre-diapause larvae were 378.12 and 291.69 μg/mg, respectively, significantly higher than those in diapause larvae (P<0.05). In one-year diapause cycle, total lipid and triglyceride contents in winter were the highest, which were 335.29 and 275.72 μg/mg in cocooned larvae in January of the next year, respectively, significantly higher than those in other stages during diapause (P<0.05). A similar seasonal variation trend was observed in total lipid and triglyceride contents of both no cocooned and cocooned larvae in one-year diapause cycle, but there were higher contents in cocooned larvae than in no-cocooned larvae at the same diapause stage. No obvious difference was found in total lipid and triglyceride contents between the 1st and 2nd year of diapause larvae (P>0.05). The total lipid and triglyceride contents reduced gradually with development after diapause termination, being significantly lower in mid-pupae and late pupae than in active larvae (P<0.05). 【Conclusion】 Total lipid and triglyceride contents in pre-diapause, diapause and post-diapause larvae and pupae of S. mosellana were significantly different, suggesting that diapause of S. mosellana is closely related to contents of lipids.