Stable flies, Stomoxys calcitrans L., are important pests of confined and pasture cattle. They have been reared in the laboratory to study their biology and to test new methods of control. Research on rearing modifications has concentrated on developing larval diets from materials locally abundant. Under current protocols, pupae form in the medium. Aggregations of pupae were located and removed, often with a considerable amount of extraneous material. Various methods have been developed to separate the pupae from waste material. We describe a method by which wandering larvae are enticed to leave the medium prior to pupariation. The larvae were attracted to a moist cloth on a shelf positioned at the end of the rearing pan. Almost 85% of the wandering larvae were collected on the shelf. This simplifies obtaining clean pupae and allows for collecting pupae of known age for experimental work. We also include data on the rate at which the larvae wandered onto the shelf under conditions we used in the laboratory.