It is one of the most representative local products in Guanyun County, Lianyungang City, Jiangsu Province. Known as "rare in the country, only in northern Jiangsu, Guanyun is unique." Doudan has high protein and low fat, rich nutrition and delicious taste, and has the effects of nourishing yin and tonifying kidney, strengthening stomach and preventing rheumatism. , and has always been regarded as a unique raw material for Guanyun dishes. Doudan, the scientific name of Doutian moth, is an insect that feeds on bean leaves and nectar and grows in a natural non-toxic and pollution-free state. High protein and low fat have the effect of warming the stomach. It has a beautiful figure, similar to a silkworm. The adult is about 5 cm long, tender green, with a dark head and a tail horn at the tail. There are seven pairs of white lines on both sides from the first abdominal section. It harms bean leaves and gnaws holes. In severe cases, plants will become bare stems and cannot bear pods.