The male has a median tubular organ (called aedeagus or phallus) which is extended through an eversible sheath (or 'vesica') to inseminate the female.
[6] While the layout of internal genital ducts and openings of the female genitalia depends upon the taxonomic group that insect belongs to, the internal female reproductive system of all Lepidopterans consists of paired ovaries and accessory glands which produce the yolks and shells of the eggs.
The oviducts of the female join to form a common duct (called the 'oviductus communis') which leads to the vagina.
The sperm, when released from the capsule, swims directly into or via a small tube (the 'ductus bursae') into a special seminal receptacle (the 'spermatheca'), where the sperm is stored until it is released into the vagina for fertilisation during egg laying, which may occur hours, days, or months after mating.
The ovipore may be at the end of a modified 'ovipositor' or surrounded by a pair of broad setose anal papillae.