locust
蝗 centers on the insect locust, a type of grasshopper known for swarming and crop destruction.
蝗 combines 虫 (insect) with 皇, which likely contributes the sound and may suggest a large or impressive insect, fitting the locust's swarming nature.
The insect radical 虫 beside 皇 (emperor) suggests the emperor of insects: a locust, ruling over fields with its swarms.
For コウ, imagine a locust wearing a tiny crown, acting like a king: king -> コウ, the emperor insect.
male Oriental longheaded locust (Acrida cinerea)
Oriental longheaded locust (Acrida cinerea)
Gonista bicolor (species of grasshopper resembling the Oriental longheaded locust)
rice grasshopper
groundhopper (esp. species Tetrix japonica)
locust plague; damage to crops by grasshoppers
rice grasshopper (of genus Oxya)
smaller longheaded locust (Atractomorpha lata)
locust swarming; locust swarm; (swarming) locusts