Most Lepidoptera larvae feed on plants 'leaves, fruit, or flower buds, and their main mission in life seems to be to get their heads down and eat for all they are worth. "Biological factors" such as a fall in the population of their natural enemies or unusually lush vegetation can quickly cause their numbers to get out of control.
鱗翅目幼蟲絕大多數以植物葉片、果實、花苞為食，它們生存的最大任務彷彿就是埋頭苦吃，若出現天敵減少、花木比往年華髮等等「生物因子」的變動，毛毛蟲族群很快就會失控。