It is said that Emperor Wu of the Han Dynasty met this bug on the road, but he didn't know what it was, so he asked Dong Fangshuo. Dong Fangshuo said that this insect is the embodiment of people who died unjustly in prison in the Qin Dynasty. It turns into sadness and will dissolve in wine. This statement is unscientific.
It was not first used by Lu Xun.