Young females are oval, 3-6 mm long and almost flat. Their shield is dark grey or brown to black and has two transverse crests and one median ridge that together form the letter H. On citrus, early stages might be yellow but they become darker later. First-instar crawlers (0.35 mm long) and intermediate immature instars are translucent light brown.
Olive scales reproduce by parthenogenesis. Eggs are protected under the shield until they hatch. The emerging crawlers settle mostly along the main veins on the lower sides of mature leaves. Many young females migrate to twigs and branches later and remain there for the rest of their lives.