Burrows Malcolm
Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
J Exp Biol. 2009 Jan;212(Pt 1):106-15. doi: 10.1242/jeb.024448.
The jumping movements of the hemipteran shore bug (Saldula saltatoria, sub-order Heteroptera, family Saldidae) were analysed from sequences of images captured at 5000 frames s(-1). Adult Saldula weigh approximately 2.1 mg and are approximately 3.5 mm long. The hind legs that propel jumping are 180% longer than the front legs and 90% of body length, but non-jumping species in the same family have longer hind legs relative to the lengths of their bodies. Jumps were powered by large trochanteral depressor muscles in the thorax in two different strategies. In the first (used in 24% of jumps analysed), a jump was propelled by simultaneous extension of the two hind legs powered by rapid depression movements about the coxo-trochanteral joints, while both pairs of wings remained closed. In the second strategy (74% of jumps), the wings were opened before the hind legs began to move. At take-off, the position of the wings was variable and could be 8-21 ms into either elevation or depression. When the hind legs alone propelled a jump, the body was accelerated in 3.97+/-0.111 ms at a take-off angle of 52+/-6.5 degrees to a take-off velocity of 1.27+/-0.119 m s(-1); when the wings also moved, the body was accelerated in 3.86+/-0.055 ms at a take-off angle of 58+/-1.7 degrees to a take-off velocity of 1.29+/-0.032 m s(-1). These values are not different in the two jumping strategies. In its best jumps the take-off velocity reached 1.8 m s(-1) so that Saldula experienced an average acceleration of 529 m s(-2), equivalent to almost 54 g, expended 3.4 microJ of energy, while exerting a force of 1.1 m N. The power requirements for jumping indicate that a catapult mechanism must be used in which the trochanteral depressor muscles contract and store energy in advance of a jump. These jumps should propel it to a height of 105 mm or 30 times its body length and distances of 320 mm. The two jumping strategies achieve the same jumping performance.
通过以5000帧/秒的速度拍摄的图像序列，对半翅目海滨蝽（盐沼跳蝽，异翅亚目，盐蝽科）的跳跃动作进行了分析。成年盐沼跳蝽体重约2.1毫克，体长约3.5毫米。用于推动跳跃的后腿比前腿长180%，是体长的90%，但同科中不会跳跃的物种相对于其身体长度而言后腿更长。跳跃由胸部的大型转节下压肌以两种不同策略提供动力。第一种策略（在分析的跳跃动作中占24%），通过围绕髋节 - 转节关节的快速下压动作驱动两条后腿同时伸展来推动跳跃，而两对翅膀保持闭合。在第二种策略（74%的跳跃动作）中，翅膀在后腿开始移动之前打开。在起跳时，翅膀的位置是可变的，可能处于上升或下降8 - 21毫秒的阶段。当仅由后腿推动跳跃时，身体在3.97±0.111毫秒内加速，起跳角度为52±6.5度，起跳速度为1.27±0.119米/秒；当翅膀也移动时，身体在3.86±0.055毫秒内加速，起跳角度为58±1.7度，起跳速度为1.29±0.032米/秒。这两个值在两种跳跃策略中没有差异。在其最佳跳跃中，起跳速度达到1.8米/秒，因此盐沼跳蝽平均加速度为529米/秒²，相当于近54g，消耗3.4微焦能量，同时施加1.1毫牛的力。跳跃的功率需求表明必须使用弹射机制，即转节下压肌在跳跃前收缩并储存能量。这些跳跃应能将其推至105毫米的高度或其体长的30倍，以及320毫米的距离。两种跳跃策略实现了相同的跳跃性能。
