Kerria lacca

Kerria lacca 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. More than 400 host plants have been noted. The species was described and given the binomial name Coccus lacca in 1781 (published formally in 1782) by the Scottish surgeon James Kerr (1737–1782) in Patna. It was then placed a new genus named after Kerr as Kerria in 1884 by Adolfo Targioni-Tozzetti (who had noted that it did not belong to Coccus even in1868). Natural predators of this species include several parasitoids, such as the parasitoid wasps Tachardiaephagus tachardiae and Coccophagus tschirchii. Predators include the moths Eublemma roseonivia and Holcocera pulverea. These moths can interfere with lac cultivation in India. These insects, as well as many types of fungal pathogens, form an ecological web that is important to local biodiversity. ==Economy==

Millions of people are engaged in the farming of lac insects. Demand, while still strong, is shrinking over time, reducing the economic viability of lac growing. The dye originates in the hemolymph of the insect; the fluid analogous to blood. ==Lac dye==

Diverse body colors are reported, including crimson and yellow. Color differences are inherited as a unit character where crimson dominates 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 2016 study has shown that the anthraquinone component of lac dye also possess antineoplastic or anticancer effects. It was suggested that lac insects employ polyketide pathway catalysed by polyketide synthase to produce laccaic acid D, a common precursor molecule for the biosynthesis of other lac dye constituents. In 2025, it was found that a yeast-like endosymbiotic organism was responsible for the synthesis of the dye. ==Lac resin==

Lac is the only commercial resin of animal origin and is a natural polymer. It is made up of hydroxy fatty acids, principally aleuritic acid (9,10,16-trihydroxyhexadecanoic acid), and hydroxy sesquiterpenic acids. A 2014 study proposes the possible biosynthetic pathway for the constituents of lac resin which identifies acetyl-CoA as a common precursor molecule and the role of prenyltransferases in the biosynthesis of sesquiterpenes along with cytochrome P450 enzyme. ==References==