Concept:The larval stage of some insects causes more damage than the adult stage.Explanation:The butterfly lays eggs that hatch into caterpillars (larvae).The caterpillar feeds voraciously on plant leaves, making it destructive to crops.The adult butterfly, however, feeds mainly on nectar and is not usually destructive to plants.Mosquito larvae are aquatic and not crop pests, bee larvae are harmless, and the millipede is not mainly destructive only at an early stage.Answer:A. butterfly