Ditrysia

Ditrysia is a clade within the order Lepidoptera that includes the vast majority of moths and all butterflies. It is one of the largest groupings of insects, comprising thousands of species across many superfamilies and families. The name Ditrysia refers to a diagnostic feature of the female reproductive system: in ditrysian species the female typically has two separate openings in the reproductive tract, one for mating and another for egg-laying, a condition that distinguishes them from more primitive lepidopteran lineages with a single opening.

Taxonomy and diversity: Ditrysia encompasses a wide range of lineages, including the large superfamilies Noctuoidea, Geometroidea, Bombycoidea, Pyraloidea, and Papilionoidea (the butterflies). Together with numerous smaller groups, they account for the overwhelming majority of Lepidoptera species, their ecological roles, and their global distribution, from pollinators to crop pests.

Evolution and significance: The origin of Ditrysia is placed in the Mesozoic era, with major diversification occurring during the Cretaceous. The group contains many economically important taxa, including numerous agricultural pests and many species that play beneficial roles as pollinators. Ditrysia exhibits extensive variation in life history, morphology, and behavior, contributing to the ecological success and diversity of Lepidoptera as a whole.