Cocoon shape, as colour, is peculiar to the given species. At the same time shape can be affected by the execution of the mounting process , especially during the cocoon spinning stage. Generally, the Japanese species is peanut-shaped, the Chinese elliptical, European a longer elliptical and the polyvoltine species spindle-like in appearance. Hybrid cocoons assume a shape midway between the parents for example, the case of a longer ellipsoid or shallowly enclosed peanut form . The shape of cocoons assists in identifying the variety of species plus evaluating reelability .