A sieving apparatus for separating pupa is described. The sieving apparatus includes a frame to support an actuation system and a basin. The actuation system is attached to a sieving device. The sieving device includes a sieve surface supported within a sieve rim. In the sieve surface are formed openings sized to correspond to a representative pupa of a population of pupae to be separated. The actuation system is configured to move the sieving device vertically with respect to the basin. For example, after a population of pupae has been added to the sieving device, the actuation system may move the sieving device into and out of a body of liquid held in the basin. This process of moving the sieving device into and out of the body can be used to separate the population of pupae based on size.
