There is regular burry-shape structure on the outer surface of pupa crust.The burries are composed of chitin-protein complex which is filled with granules of inorganic salts.

• 柞蚕蛹皮外表面呈规整“毛刺”状结构，“毛刺”主要由几丁质/蛋白质复合物组成，颗粒状无机盐均匀分布在该复合物的表面上。