Purple Scale Predator

Rhyzobius lophanthae is a small ladybird with a length between 1.7 and 2.85 mm (0.07 and 0.11 in) and a width of between 1.35 and 2.0 mm (0.05 and 0.08 in). The head and prothorax are reddish-brown, as is the underside, both being densely covered with short hairs of two lengths. The elytra (wing cases) are blackish, often with a metallic bronze sheen. The larvae are dark brown and is clad in stout spines.

Rhyzobius lophanthae is native to Australia where it is present in Queensland and Southern Australia. It was introduced into California in 1892 in an attempt to control the olive scale (Saissetia oleae). It has since spread over much of the southern United States. It can also be found in Europe.

Both adults and larvae feed on scale insects, and especially on armoured scales at all periods of their development; they also feed on mealybugs. The younger beetle larvae crawl under the adult scale insect's protective scale, feeding on the scale nymphs before they disperse. These insects are a pest of citrus, sucking the sap from the plants, and the ladybirds have been used in biological pest control, in order to reduce the number of scale insects in the crop.