Neuromuscular and biomechanical compensation for wing asymmetry in insect hovering flight
Neuromuscular and biomechanical compensation for wing asymmetry in insect hovering flight
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DOI：
10.1242/jeb.073627
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发表时间：
2012-10-01
影响因子：
2.8
通讯作者：
Hedrick, Tyson L.
中科院分区：
文献类型：
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作者：
Fernandez, Maria Jose;Springthorpe, Dwight;Hedrick, Tyson L.
翅膀损伤在飞行昆虫中很常见，并且已经使用多种方法进行了研究，以评估其生物力学和健康后果。这些研究的结果在不同物种、适应性测量和所研究的损害模式之间存在从强到零的影响，这表明并非所有损害模式都是相同的，并且昆虫可能很好地适应了补偿某些类型的损害。在这里，我们研究了飞行昆虫补偿不对称翅膀损伤的生物力学和神经肌肉手段，预计这会产生不对称的飞行力和扭矩，从而除了减小其翅膀总尺寸外，还会使动物不稳定。我们通过高速摄像和细胞外神经肌肉活动记录，测量了翅膀不对称受损的天蛾（Manduca sexta）自由飞行时的运动学和神经肌肉反应。动物对不对称机翼损伤做出反应，机翼行程幅度的不对称变化足以恢复升力产生的对称性。这些中风幅度的不对称性与试验期间和试验内背腹肌激活时间的双侧不对称性显着相关。相应地，翅膀不对称的程度与个体之间神经肌肉反应的程度显着相关，尽管是非线性的。这种关系的强非线性性质表明，对于不对称机翼损伤的主动神经补偿可能只需要高于阈值（在这种情况下，机翼面积二阶矩的不对称性>12%），低于该阈值，被动机制可能足以维持飞行稳定性。
Wing damage is common in flying insects and has been studied using a variety of approaches to assess its biomechanical and fitness consequences. Results of these studies range from strong to nil effect among the variety of species, fitness measurements and damage modes studied, suggesting that not all damage modes are equal and that insects may be well adapted to compensate for some types of damage. Here, we examine the biomechanical and neuromuscular means by which flying insects compensate for asymmetric wing damage, which is expected to produce asymmetric flight forces and torques and thus destabilize the animal in addition to reducing its total wing size. We measured the kinematic and neuromuscular responses of hawkmoths (Manduca sexta) hovering in free flight with asymmetrically damaged wings via high-speed videography and extracellular neuromuscular activity recordings. The animals responded to asymmetric wing damage with asymmetric changes to wing stroke amplitude sufficient to restore symmetry in lift production. These asymmetries in stroke amplitude were significantly correlated with bilateral asymmetries in the timing of activation of the dorsal ventral muscle among and within trials. Correspondingly, the magnitude of wing asymmetry was significantly, although non-linearly, correlated with the magnitude of the neuromuscular response among individuals. The strongly non-linear nature of the relationship suggests that active neural compensation for asymmetric wing damage may only be necessary above a threshold (>12% asymmetry in wing second moment of area in this case) below which passive mechanisms may be adequate to maintain flight stability.