Architecture and composite structure of hornet cuticle (Insecta, Hymenoptera)

The present study is devoted to the microstructure of the cuticle in the gastral segments of the Oriental hornet Vespa orientalis. In order to elucidate the architectural structure in the region of the abdominal strips endowed with yellow pigment, sections were prepared for viewing via scanning electron microscope (SEM) and these revealed that the cuticle in the named regions is of a layered nature, composed of duplex layers, each consisting of a thin double wall of chitin enclosing a filling of proteins as a matrix. There are 30 or more such layers which become progressively thinner as one proceeds from the outside interiorly. A statistical model that describes this decrease in layer thickness was accordingly developed. The semi-log plots obtained from the studied specimens show that the logarithm of layer thickness tends to decrease approximately as a linear function of the number of layers. The importance of such vespan type of architectonics is discussed in terms and is compared with similar structures both in nature and in industry.