Kerria lacca is a species of insect in the family Kerriidae, the lac insects. These are in the superfamily Coccoidea, the scale insects. This species is perhaps the most commercially important lac insect, being a main source of lac, a resin which can be refined into shellac and other products. This insect is native to Asia.
Kerria lacca also produces a dye and a wax as natural secretions. The life cycle of this scale insect proceeds with the first instar of the larval stages, which are known as "crawlers". Larvae in this stage crawl along the branches of their host plants and feed on the phloem. As they pierce the branches to reach the phloem, they cover the holes with their wax secretions. Lac insects showing diverse body colours have been reported, they may show crimson or yellow body colours. Colour difference in lac insect is inherited as a unit character and crimson is dominant to yellow. Wild type insect possesses crimson body colour due to the presence of a complex closely resembling water-soluble polyhydroxy-anthraquinones, collectively called lac dye. Apart from their usage in food and cosmetics, these anthraquinones also exhibit many pharmaceutical properties, including antibiotic, antiviral, antifeedant effect. A recent study has shown that the anthraquinone component of lac dye also possess antineoplastic or anticancer effects.
Laccifer lacca is used in the conditions of injuries, fungal infections, eczema, scabies and herpes. Internal uses include treatment of diarrhea, dysentery, intestinal parasites (worms), internal bleeding disorders, hiccup and cough. In Unani, Lac is considered tonic for liver, stomach and intestine.