Global warming not only alters phenology but also nutritional quality and defense compounds in plants, which consequently hinders their defense against herbivorous insects. In this study, the performance of Spodoptera litura was analyzed to observe the effects of high temperatures on chemical-based defense in plants in the context of insect–plant interaction. Results show that high temperature reduced the nutritional value and content of defense compounds in the foliage of yellow cress (Rorippa dubia). These alterations negatively affected the performance of second instar S. litura larvae feeding on plants grown at high temperature. Low quality of the food source is likely the key cause of slow development of larvae. Adaptation of herbivorous insects known as compensatory feeding is projected resulting in more crop losses under global warming. Our data reveal temperature-induced reduction in the content of defensive compounds (in constitutive resistance) along with lower response capability against herbivore attacks (in induced resistance), which indicate a decrease in plant fitness. High temperatures caused by global warming negatively affect crop production and are expected to increase the burden on plant protection practices.

中文翻译：

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高温会减少Rorippa dubia的通才Spodoptera litura F.的营养物质和防御化合物

全球变暖不仅改变了植物的物候，而且改变了植物的营养品质和防御性化合物，因此阻碍了它们对草食性昆虫的防御。在这项研究中，分析了斜纹夜蛾的性能，以观察高温在昆虫与植物相互作用的情况下对植物基于化学的防御作用的影响。结果表明，高温降低了黄水芹（Rorippa dubia）叶片的营养价值和防御化合物的含量。这些改变负面影响了第二龄S. litura的表现。以高温生长的植物为食的幼虫。食物来源质量低下可能是幼虫发育缓慢的主要原因。预计将对草食性昆虫进行适应性耕作，即补偿性饲养，这将导致全球变暖导致更多的农作物损失。我们的数据显示，温度诱导的防御性化合物含量减少（本构抗性），以及对草食动物攻击的响应能力降低（诱导抗性），表明植物适应性降低。全球变暖造成的高温对作物生产产生负面影响，预计将增加植物保护措施的负担。