3.1. Surface and cross-sections of cocoon shells
Being a typical protective structure, the surface of the cocoon shells exhibited extensive variation to meet the specific needs of a given species. A. panda and G. postica cocoon shells had dense white and brown hairs and spines embedded from the body of the larvae during spinning. The average diameter of A. panda hair was 34 μm and had thorny spines (6–8 μm in diameter) arranged alternatively over the surface ( Fig. 1a). Gonometa cocoons had short white hairs interwoven throughout the cocoon layers while the brown needle-like spines with sharp buds on their surface were found attached to the outer cocoon surface ( Fig. 1b). The sharpness of the buds decreased towards the base of the spines.