The Ditrysia are a natural group or clade of insects in the Lepidopteran order containing both butterflies and moths. They are so named because the female has two distinct sexual openings: one for mating, and the other for laying eggs (in contrast to the Monotrysia).

The Ditrysia are a natural group or clade of insects in the Lepidopteran order containing both butterflies and moths. They are so named because the female has two distinct sexual openings: one for mating, and the other for laying eggs (in contrast to the Monotrysia).