Additional close-up detail for sighting 4463213. The first image shows a close-up of the wing's light brown coloured pterostigma, which is a thickened and coloured cell in the outer wing. The apparent purpose of the pterostigma, being a heavier section of the wing in comparison to nearby sections, is to assist the lacewing in gliding and in raising the insect's critical flight speed. Without the pterostigma, self-exciting vibrations or flapping would set in on the wing after a certain critical speed, reducing flight speed and making gliding impossible.