稻纵卷叶螟幼虫对不同氮、糖含量人工饲料的营养消耗和利用

Nutritional consumption and utilization by Cnaphalocrocis medinalis larvae of artificial diets with different nitrogen or sugar contents

本文以不同氮、糖含量的系列人工饲料为材料,研究了稻纵卷叶螟Cnaphalocrocis medinalis Guenée幼虫的营养消耗和利用。结果表明,3龄幼虫对不同氮或糖含量饲料的营养指标之间无显著差异、其对氮的消耗与利用指标与试验中饲料的含氮量之间也无显著关系;对于5龄幼虫而言,相对生长速率(RGR)以氮含量1.53%和1.16%饲料时最高、糖含量为16.75%饲料时RGR最高,氮消耗速率(NCR)在氮含量1.46%饲料时最大,在氮含量1.33%和1.46%饲料上的氮利用率(NUR)值最低。5龄幼虫取食高氮饲料时的NUR及NCR高于低氮饲料。5龄幼虫的氮利用率和氮生成速率(NPR)均低于3龄幼虫,导致虫体含氮量的迅速下降。这些结果表明稻纵卷叶螟3龄幼虫对氮的需求与利用比5龄幼虫高。

This study focused on the nutritional composition and growth of Cnaphaloerocis medinalis Guen6e, an important rice insect pest in China, on artificial diets containing different nitrogen or sugar contents. Nutritional indices of 3rd instar larvae were not significantly affected by diets with different nitrogen or sugar content and nitrogen consumption and utilization by 3rd instar larvae were not significantly affected by different nitrogen content. However, the relative growth rate （RGR） of 5th instar larvae peaked when nitrogen content was 1.53% or 1.16% , and RGR was highest on the diet with 16.75% sugar content. Nitrogen consumption rate （NCR） of 5th instar larvae was highest on the diet with 1.46% nitrogen content, and nitrogen utilization rate （NUR） was lowest when nitrogen content was 1.33% or 1.46%. 5th instar larvae fed with a higher nitrogen content diet had higher NCR than those with lower nitrogen content in the diet. Lower NUR and nitrogen production rate （NPR） in 5th instar larvae compared with 3rd instar larvae resulted in reduced body nitrogen content. The results also indicate that 3rd instar larvae have higher requirements and utilization of nitrogen than 5th instar larvae.