The Monotrysia is a group of insects in the Lepidopteranorder which is not currently considered to be a natural group or clade. The group contains only moths and most of these (apart from the recently discovered familyAndesianidae) are small and are relatively understudied (compared to Ditrysia) in many regions of the world. The group is so named because the female has a single genital opening for mating and laying eggs, in contrast to the bulk of the Lepidoptera (Ditrysia), which have two female reproductive openings. They comprise all of the group Heteroneura but the Ditrysia.
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