??C (64 ??F) it takes 19 days[5][6] and at 12 ??C (54 ??F) it takes over 50 days.[5][6] Under crowded conditions, development time increases,[8] while the emerging flies are smaller.[8][9] Females lay some 400 eggs (embryos), about five at a time, into rotting fruit or other suitable material such as decaying mushrooms and sap fluxes.