locust

蝗 is composed of 虫 (insect) and 皇 (emperor). 虫 here refers to insects, while 皇 means emperor and also carries the sense of grandeur. Thus, 蝗 denotes an insect capable of causing large-scale destruction. When locusts (蝗) swarm, they blot out the sky, on a scale as vast as an imperial procession.