Tekkit 2; Minecraft 1.12.2; no custom modifications to the Pack: Enclosed my Forestry breeding area under a dome of Pigmented Glass (Light Blue) and butterflies don't seem to recognize it as being a clear ceiling and thus won't pollinate or leave cocoons. Apiaries work fine. Was able to duplicate the effect on a test world and Vanilla normal and Stained Glasses do not hinder pollination.