What makes Blepharida jump? A structural study of the metafemoral spring of a flea beetle

Blepharida sacra (Weise) is one of many species of flea beetles that have remarkable jumping abilities. The energy for its prodigious leaps is evidently stored in a central scroll‐shaped organ inside the hind femur of this insect—the metafemoral spring. X‐ray diffraction, scanning electron microscope, and analytical studies have established that this structure consists primarily of well‐oriented fibers of the polysaccharide α‐chitin, together with protein. The composition and orientation of these fibers appear to explain the role of this organ in the flea beetle jumping mechanism.