A sleek abdomen reflects light creating the illusion of movement as well as adds weight to the nymph, helping it sink for deeper water. This pattern was developed specifically to imitate zebra midges in even their smallest sizes. Per 3. Sizes: 12, 14, 16, 18, 20, 22. Color: Zebra. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Flies.