A sieving device is described. The sieving device includes an adjustable sieve surface that includes a first sieve surface and a second sieve surface. Openings are formed in each of the first sieve surface and the second sieve surface so as to define a shared pathways extending through the adjustable sieve surface. The shared pathways are defined by a length dimension that is greater than a width dimension. The width dimension can correspond to a cephalothorax width of an insect.
