The armyworm is also a resource insect. Lac was first used as a medicinal material and then as a dye.
Many ancient books are recorded as dyes. Lu Wu said that lac can dye floc, that is, silk fabric; Su Gong said that we can dye fur and jewelry, while Su Song said in Compendium of Materia Medica that today's medical prescriptions are rarely used, and only the dyers need them, which shows that in the Song Dynasty, lac was used as a dye, which exceeded medicinal use.
Lac used in ancient China may have been imported from abroad, and the origin recorded in ancient books includes Qinghua Province, Zhenla, Persia, Kunlun, Hainan, Jiaozhou and Nanfan in central Vietnam. Although it is mentioned that lac is also produced in China, it may be imported from abroad because it is inconvenient to transport by land and not by sea.
Xu Xiake's travel notes made it clear for the first time that Yunnan Province is the producing area of lac in China, and Yunnan Province has always been the main producing area of lac in China. Lace produced in Yunnan Province is exported to foreign countries at a low price, which occupies a considerable amount in the international market.
When Xu Xiake, a famous geographer in Ming Dynasty, visited Yunnan, he first pointed out that Yunnan was the origin of lac in China, and described the morphology of purple stem tree, a parasitic plant of lac insect.