Scale insect. Coloured scanning electron micrograph (SEM) of a scale insect (superfamily Coccoidea) from the Colombian jungle. Scale insects are bugs that feed on plant sap and are therefore often considered pests. Adult males usually have wings (depending on their species) but never feed, and die within a day or two. The females usually live in large colonies on different plant parts. Their body is shield-shaped and often enclosed in a capsule, in many species the females are completely immobile. Magnification: x40, when printed 15cm wide.