体型粗大,是昆虫中最大的一类,如大乌桕蚕的翅展可达185mm。而且色泽绚丽,五彩缤纷。触角羽毛状,啄短小,无单眼,下唇须一般小而直,密被毛。翅宽大,中室端一般具眼状斑纹或月牙形斑纹,M2接近M1出自中室上角,中室开者则M2与M1共柄,无1A;前翅 Large size, is the largest of a class of insects, such as the big black silkworm wingspan up to 185mm. And brilliant color, colorful. Feathery antennae, pecking short, no monocular, lower lip to be generally small and straight, dense coat. Wings wide, mid-chamber end generally with eye-shaped markings or crescent-shaped markings, M2 is close to M1 from the upper corner of the room, M2 and M1 were co-shank joint, no 1A;