Temperature‐by‐nutrient interactions affecting growth rate in an insect ectotherm
Temperature‐by‐nutrient interactions affecting growth rate in an insect ectotherm
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温度与养分的相互作用影响昆虫变温动物的生长速度
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
C. Roh
中科院分区：
文献类型：
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作者：
K. Lee;C. Roh
温度和营养是影响变温动物幼鱼生长速度的两个重要环境变量。这两个因素以复杂的方式相互作用。本文综合分析了温度和营养对植食性昆虫——斑点夜蛾幼虫（Spodoptera exigua h<e:1> bner，鳞翅目：夜蛾科）的适合度（生长率、存活率）、食物摄取量和能量储存水平的相互作用。在析因试验设计中，末龄幼虫（即5龄幼虫）被单独饲养在三种恒温（18、26和34°C）中的一种环境中，它们接受六种不同蛋白质和可消化碳水化合物比例的饲料中的一种[P:C混合物，以饲料中干质量的百分比表示：蛋白质42%：碳水化合物0%(42:0),35:7,28:14,21:21,14:28和7:35]。在试验温度范围内，幼虫的生长速率随温度升高而升高，并受磷碳混合料的强烈影响，在各温度下，中等磷碳混合料的幼虫生长速率最高，在高磷碳混合料和低磷碳混合料的幼虫生长速率下降。温度与饲粮之间存在显著的相互作用，在中等P:C饲粮中，生长速率差异最大，在最极端的饲粮中，生长速率差异最小（42:0和7:35）。食物摄取率模式与生长速率有相似的趋势。在高温环境下，快速生长的动物在所有P:C混合饲粮中死亡率都很高，但在极不平衡的饲粮中死亡率更高。这表明在高温下快速生长有发育和生理代价，如高化蛹失败率和降低脂质储存效率。我们的研究显示了温度和营养如何相互作用来介导昆虫变温动物生长速率和能量利用的表型变化。
Temperature and nutrition are two prominent environmental variables influencing juvenile growth rate in ectotherms. These two factors interact in complex ways. Here, we present a comprehensive analysis of the interactive effects of temperature and nutrition on various components of fitness (growth rate, survival), food intake, and level of energy storage in an insect herbivore, caterpillars of Spodoptera exigua Hübner (Lepidoptera: Noctuidae). In a factorial experimental design, final‐instar caterpillars (i.e., fifth instars) were individually reared at one of three constant temperatures (18, 26, and 34 °C), in which they received one of six diets differing in their ratio of protein and digestible carbohydrate [P:C mixture, expressed as the percentage of diet by dry mass: protein 42%:carbohydrate 0% (42:0), 35:7, 28:14, 21:21, 14:28, and 7:35]. Within the range of test temperatures, larval growth rate increased with rising temperature and was strongly affected by P:C mixture, reaching a maximum on moderate P:C diets at each temperature and falling at very high and low P:C mixtures. There was a significant temperature*diet interaction, such that the difference in growth rates between temperatures was greatest on moderate P:C diets and least on the most extreme diets (42:0 and 7:35). Food intake rate patterns followed a similar trend to growth rate. Rapidly growing animals at high ambient temperature suffered high mortality across all dietary P:C mixtures, but to a greater extent on the extremely unbalanced diets. This suggests that there are developmental and physiological costs associated with fast growth at high temperature, as indicated by high rate of pupation failure and reduced lipid storage efficiency. Our study shows how temperature and nutrition interplay to mediate phenotypic variations in growth rates and energy utilization in an insect ectotherm.