Dispersion. The study of dispersions of larvae in the field is complicated by effect of weather, local substrate variation and scavenging by the dog and wild animals. The simplest experimental design involves enclosing a colony of a grassy in a 1/2 inch mesh hardware cloth box. anchor The box in the center using large spike. Arrange 100 square tiles in a circle 8 m. in diameter with the colony at this center. Allow the colony to disperse, checking the tile daily until pupae are obvious beneath the tile. Count the number of pupae beneath each of the tile quadrats.