NERVURE • DICTIONARY ONE.COM • Definition of Nervure

... sounds, we found, were produced by the overlapping edges of the wing-cases, which they rub together. In each wing-case the inner edge, near the lower part, has a horny expansion. On one wing this horny expansion is furnished with a sharp raised margin; on the other, the strong nervure which traverses it on the other side is crossed by a number of short, sharp furrows, like those of a file. When, therefore, the insect rapidly moves its wings, the file of one expansion scrapes sharply across the horny margin ...

— On the Banks of the Amazon • W.H.G. Kingston