Lepidoptera, an order of insects characterised by the fact that the wings are covered with scales, and including the moths and butterflies. The mouth parts form a tube, coiled when not in use, through which the food (honey) is sucked. There are four similar wings. The members of this group pass through a complete metamorphosis, their larvae being the common caterpillars, some of which cause great destruction to fruit-trees, etc. The silkworm moths are the only ones of any commercial importance.