Kwik-Key to Common Families of Lepidoptera
To make further progress in this key you will have to examine the pattern of wing venation. Put a few drops of clear nail polish remover (xylene or toluene) on the wing to wet the scales and reduce their optical density. Shine a bright light on white paper behind the wing and you will be able to see the veins in silhouette. The wing will return to its original appearance as soon as the liquid evaporates.
