The Halimococcidae differ from Phoenicococcidae and Diaspididae mainly in the structure of the pygidium (formed by fusion of abdominal segment IV and posterior segments) in the second instar female; it is dorso-ventrally flattened and sclerotized, with a hinged, dorsal operculum (oval to round and often reticulated), surrounded by a sclerotized rim; the dorsal anus is situated within this rim. The second instar female possesses quinquelocular pores associated with the spiracles. In contrast, the adult female normally remains membranous and the pygidium is simple; the body usually has numerous spicules and blunt points present; the antennae are reduced to tubercles, each with 2-5 setae; and there are no quinquelocular pores associated with the spiracles. In both the second instar and adult female, each tubular duct has an 8-shaped cross-section, at least towards the inner end. The scale of the pupillarial adult female is formed by the exuviae of the second instar. Adult males, where known, are degenerate and wingless (Williams and Watson, 1990).