Niven Jeremy E, Scharlemann Jörn P W
Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
Biol Lett. 2005 Sep 22;1(3):346-9. doi: 10.1098/rsbl.2005.0311.
Energetically costly behaviours, such as flight, push physiological systems to their limits requiring metabolic rates (MR) that are highly elevated above the resting MR (RMR). Both RMR and MR during exercise (e.g. flight or running) in birds and mammals scale allometrically, although there is little consensus about the underlying mechanisms or the scaling relationships themselves. Even less is known about the allometric scaling of RMR and MR during exercise in insects. We analysed data on the resting and flight MR (FMR) of over 50 insect species that fly to determine whether RMR and FMR scale allometrically. RMR scaled with body mass to the power of 0.66 (M0.66), whereas FMR scaled with M1.10. Further analysis suggested that FMR scaled with two separate relationships; insects weighing less than 10mg had fourfold lower FMR than predicted from the scaling of FMR in insects weighing more than 10mg, although both groups scaled with M0.86. The scaling exponents of RMR and FMR in insects were not significantly different from those of birds and mammals, suggesting that they might be determined by similar factors. We argue that low FMR in small insects suggests these insects may be making considerable energy savings during flight, which could be extremely important for the physiology and evolution of insect flight.
高能量消耗行为，如飞行，会将生理系统推向极限，这需要代谢率（MR）大幅高于静息代谢率（RMR）。鸟类和哺乳动物在运动（如飞行或奔跑）时的RMR和MR均呈现异速生长，尽管对于其潜在机制或异速生长关系本身几乎没有共识。对于昆虫运动时RMR和MR的异速生长，人们了解得更少。我们分析了50多种会飞行昆虫的静息代谢率和飞行代谢率（FMR）数据，以确定RMR和FMR是否呈异速生长。RMR与体重的0.66次方成正比（M0.66），而FMR与M1.10成正比。进一步分析表明，FMR遵循两种不同的关系；体重小于10毫克的昆虫的FMR比体重大于10毫克的昆虫的FMR按比例缩放预测值低四倍，尽管两组均与M0.86成正比。昆虫的RMR和FMR的缩放指数与鸟类和哺乳动物的缩放指数没有显著差异，这表明它们可能由相似的因素决定。我们认为，小型昆虫的低FMR表明这些昆虫在飞行过程中可能节省了大量能量，这对昆虫飞行的生理学和进化可能极其重要。
