A new method is described for preparing slide mounts of whole bodies of microlepidoptera to facilitate comparative morphological studies. This method conserves traditional characters of wing pattern while revealing wing venation and other morphological structures of the denuded body. Examples of new characters revealed on slide mounts of whole bodies and photographed with a Confocal Laser Scanning Microscope are given for selected species of Gelechioidea. Also, the historical use of morphological characters for defining taxa of Lepidoptera is briefly reviewed.