What do woolly aphids look like?

Fluffy, wool-like white wax over blue- or green-colored, one-fourth inch- (0.64-centimeter-) diameter insect bodies is the look of woolly aphids. The insects in question (Aphidoidea superfamily) prey upon nutrient-rich xylem and sugar-rich phloem, as expected of a plant sap-sucking aphid, but by way of the bark instead of the foliage. The waxy look vanishes when woolly aphids overwinter in bark cracks and crevices.