Abstract: 【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.

Key words:  Sitodiplosis mosellana, diapause, lipids, total lipids, triglyceride, vanillin-sulfuric acid colorimetry