Testing the plant stress hypothesis: stressed plants offer better food to an insect herbivore
Testing the plant stress hypothesis: stressed plants offer better food to an insect herbivore
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DOI：
10.1111/eea.12118
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发表时间：
2013-11-01
影响因子：
1.9
通讯作者：
Fischer, Klaus
中科院分区：
文献类型：
--
作者：
Bauerfeind, Stephanie S.;Fischer, Klaus
温度和营养是影响变温动物生长的最重要的环境因素。由于温度和寄主植物质量在自然界中经常共同变化，两者之间的相互作用对草食性昆虫具有潜在的高度生态重要性。本文以温带蛱蝶（鳞翅目：蝶科）为研究对象，研究了不同温度和寄主植物质量（通过调节水分有效性）对幼虫生长的交互影响。由于生长速率被假设为控制胁迫耐受性，我们额外评估了成人的饥饿抗性。蝴蝶遵循“温度-尺寸规则”，即在较低的发育温度下，体型会增加，这直接是由于生长增量的差异造成的，而生长增量是由于较低温度下消耗的增加造成的。幼虫在低水环境中以受胁迫的植物为食，从而获得更高的体重、生长速度和食物转化效率，从而支持植物胁迫假说，该假说预测，如果植物受到胁迫，食草动物的植物质量会提高。有些寄主-植物品质对幼虫生长参数的影响与温度的影响一样强，甚至更强，而温度与食物品质之间的交互效应很少。低温条件下，成虫对饥饿的抗性高于高温条件下，雌虫对饥饿的抗性高于雄虫，而植物水分状况对其抗性无明显影响。没有证据表明生长速度和饥饿抗性之间存在权衡关系。本研究说明了在评估环境变化对草食性物种的影响时，考虑寄主植物品质和其他环境因子变化的影响的重要性。
Temperature and nutrition are among the most important environmental factors affecting ectotherm growth. As temperature and host-plant quality often co-vary in nature, the interaction between the two is of potentially high ecological importance for herbivorous insects. We here use the temperate-zone butterfly Pieris napi L. (Lepidoptera: Pieridae) to investigate interactive effects of larval rearing temperature and host-plant quality (by manipulating water availability) on larval growth. As growth rates have been hypothesized to govern stress tolerance, we additionally assessed adult starvation resistance. Butterflies followed the temperature-size rule', which states that body size increases at lower developmental temperatures, proximately caused by differences in growth increment, which resulted from increased consumption at the lower temperature. Larvae benefitted from feeding on stressed plants from the low-water regime by having higher body mass, growth rate, and food conversion efficiency, thus supporting the plant stress hypothesis, which predicts that plant quality for herbivores should increase if stress is imposed on plants. Some effects of host-plant quality on larval growth parameters were as strong as or even stronger than effects of temperature, whereas interactive effects between temperature and food quality were scarce. At the low temperature, adult starvation resistance was higher than at the higher temperature and females were more resistant than males, whereas plant water regime had no clear impact. No evidence was found for a trade-off between growth rate and starvation resistance. This study illustrates the importance of considering effects of host-plant quality along with variation in other environmental factors for estimating the impact of environmental changes on herbivorous species.