See
Taxonomy of Lepidoptera and
Lepidopteran diversity.
Lepidopterans like all holometabola, undergo complete metamorphosis, going through a four-stage life cycle of egg - larva/caterpillar - pupa/chrysalis - imago/adult.[2] Their lifecycle can include an inactive period or diapause in any of the pre-adult stages that helps overcome unsuitable environmental conditions.[2]
The larvae, caterpillars, have a toughened (sclerotized) head capsule, chewing mouthparts, and a soft body, that may have hair-like or other projections, 3 pairs of true legs, and additional prolegs (up to 5 pairs). They can be confused with the larvae of sawflies. Lepidopteran larvae can be differentiated by the presence of crochets on the prolegs which are absent in the Symphyta (sawflies). Most caterpillars are herbivores, but a few are carnivores (some eat ants or other caterpillars) and detritivores.[3]
Adults have two pairs of membranous wings covered, usually completely, by minute scales. In some species, wings are reduced or absent (often in the female but not the male). Antennae are prominent. In moths, males frequently have more feathery antennae than females, for detecting the female pheromones at a distance. The Trichoptera (caddisflies) which are a sister group of the Lepidoptera have scales, but also possess caudal cerci on the abdomen, a feature absent in the Lepidoptera.[2]
