Yang Yuelong, Stamp Nancy E
Department of Biological Sciences, Binghamton University, State University of New York, 13902-6000, Binghamton, NY, USA.
Oecologia. 1995 Oct;104(2):225-233. doi: 10.1007/BF00328587.
One effect of global warming may be an increase in night-time temperatures with daytime temperatures remaining largely unchanged. We examined this potential effect of global warming on the performance of tobacco hornworm larvae, Manduca sexta (Sphingidae), by manipulating night-time temperature and dietary rutin levels simultaneously under a 12 light:12 dark photoregime. All four thermal regimes (26:14, 26:18, 26:22, and 26:26° C) had a daytime temperature of 26° C, with the night-time temperature increased from 14 to 26° C by increments of 4° C. Dietary rutin levels (0, 10 and 20 μmoles g fresh weight of diet) reflected those occurring naturally in the leaves of tomato, a preferred host plant of M. sexta. With low night-time temperatures (14 and 18° C), rutin had a negative linear effect on developmental rate, relative growth rate and relative consumption rate of the caterpillars. However, at a night-time temperature of 22° C, rutin had a negative non-linear effect. At a night-time temperature of 26° C, rutin had a negative linear impact but less so than at the other nightime temperatures. Likewise, the negative effect of rutin on molting duration was mitigated as night-time temperature increased. Final larval weight decreased linearly with increased dietary rutin concentrations. Total amount of food ingested was not affected by either rutin or thermal regime. As expected, the caterpillars developed faster under an alternating 26:14° C regime than a constant 20° C regime (the average temperature for the alternating regime), but the effect of rutin depended on the thermal regime. Switching daytime and night-time temperatures had no statistically significant effect on caterpillar performance. Overall, the effect of rutin on rates of larval performance was greater at some levels of warmer nights but damped at another level. These results indicate that the potential effect of warmer nights on insect performance is not a simple function of temperature because there can be interactions between night-time temperature and dietary allelochemicals.
全球变暖的一个影响可能是夜间温度升高，而白天温度基本保持不变。我们通过在12小时光照:12小时黑暗的光周期下同时控制夜间温度和饮食中芦丁水平，研究了全球变暖对烟草天蛾幼虫（烟草天蛾，天蛾科）生长性能的这种潜在影响。所有四种热环境（26:14、26:18、26:22和26:26°C）的白天温度均为26°C，夜间温度以4°C的增量从14°C升高到26°C。饮食中的芦丁水平（0、10和20微摩尔/克饮食鲜重）反映了烟草天蛾偏好的寄主植物番茄叶片中自然存在的水平。在夜间温度较低（14和18°C）时，芦丁对毛虫的发育速率、相对生长速率和相对消耗速率有负线性影响。然而，在夜间温度为22°C时，芦丁有负非线性影响。在夜间温度为26°C时，芦丁有负线性影响，但比其他夜间温度时的影响小。同样，随着夜间温度升高，芦丁对蜕皮持续时间的负面影响得到缓解。幼虫的最终体重随着饮食中芦丁浓度的增加呈线性下降。摄入的食物总量不受芦丁或热环境的影响。正如预期的那样（交替的26:14°C环境下的毛虫比恒定的20°C环境下发育得更快（交替环境的平均温度）），但芦丁的影响取决于热环境。切换白天和夜间温度对毛虫的生长性能没有统计学上的显著影响。总体而言，在某些较温暖夜晚的水平下，芦丁对幼虫生长速率的影响更大，但在另一个水平下则受到抑制。这些结果表明，较温暖夜晚对昆虫生长性能的潜在影响不是温度的简单函数，因为夜间温度和饮食中的化感物质之间可能存在相互作用。
