![]() Īrthropods often use deformation of their exoskeleton as an elastic energy store, particularly when generating fast and powerful predatory strikes or when jumping. In this study, we analyse the nature and action of specialised structures that store and release energy to power the most effective jumping insect so far described, the froghopper. Animals that use movements demanding both high speed and power have to overcome these limitations by slowly deforming elastic structures to maximise the energy stored, and then deliver this stored energy by rapid recoil. The balance between these two extremes sets a functional limit to the amount of power (energy/time) that a muscle can generate. A muscle can either contract rapidly and generate limited energy, or it can contract slowly to generate its maximal energy. Movements that are both fast and powerful must overcome the constraints imposed by the properties of striated muscle. Muscle contractions bend the chitinous cuticle with little deformation and therefore, store the energy needed for jumping, while the resilin rapidly returns its stored energy and thus restores the body to its original shape after a jump and allows repeated jumping. The composite structure therefore, combines the stiffness of the chitinous cuticle with the elasticity of resilin. The stiffer cuticular parts of the pleural arches could, however, easily meet all the energy storage needs. ConclusionĬalculations showed that the resilin itself could only store 1% to 2% of the energy required for jumping. ![]() Stimulating one trochanteral depressor muscle in a pattern that simulates its normal action, results in a distortion and forward movement of the posterior part of a pleural arch by 40 μm, but in natural jumping, the movement is at least 100 μm. No other structures in the thorax or hind legs show this blue fluorescence and it is not found in larvae which do not jump. The ventral and posterior end of this fluorescent region forms the thoracic part of the pivot with a hind coxa. They are built of chitinous cuticle and the rubber-like protein, resilin, which fluoresces bright blue when illuminated with ultra-violet light. The hind coxae of the froghopper are linked to the hinges of the ipsilateral hind wings by pleural arches, complex bow-shaped internal skeletal structures. The fastest of the insect jumpers, the froghopper, uses a catapult-like elastic mechanism to achieve their jumping prowess in which energy, generated by the slow contraction of muscles, is released suddenly to power rapid and synchronous movements of the hind legs. ![]() This allows them to release large amounts of energy in a very short time to jump at very high speeds. Many insects jump by storing and releasing energy in elastic structures within their bodies.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |