STONEFLIES are an order of insects, like Mayflies and Dragonflies that have only 2 stages after eggs. Their larvae, nymphs, also live most of their lives in water, which must be clean, as pollution is not tolerated. When mature, they crawl out and shed their skins to become winged adults, with no pupal stage as in more advanced insects. They are one of the earliest, with related fossils from the Carboniferous. They are organized by relationship below. Click on thumbnails for larger images.