In Vietnam, lac resin is used for tooth dyeing, but in some countries in the region like India and Thailand, the production of lac resin for export has been a lucrative technology for thousands of years.
Lac Insects:
There are about 2,000 species of scale insects, commonly referred to as lac insects (Laccifer lacca or Coccus lacca), ranging from 1 mm to over 2.5 cm in length. They are parasitic on suitable plants such as the jujube, the lotus palm, and the mulberry tree in the northern regions of Vietnam, producing a substance called “lac.” The resin is harvested by scraping off this layer (along with the insects that produce it). It takes about 300,000 insects to produce 1 kg of lac resin.
Lac insects have a relatively short lifespan, consisting of four stages: egg, larva, pupa (or chrysalis), and adult. Their life cycle is very ephemeral, lasting only 5 to 6 months. Therefore, places that cultivate lac insects can harvest twice a year. The lac insects live parasitically, attaching to a small branch of a tree, and remain mostly immobile. The female can lay about 100 eggs in a sac attached to her body. The eggs hatch into larvae, approximately 0.5 mm long, which break free from the sac, crawl out, and firmly attach to a branch. The larvae have a long appendage that helps them penetrate the tree bark and suck the sap for sustenance.
The larval body gradually secretes a sticky substance that hardens upon exposure to air, becoming thicker and forming a protective resinous shield. The larva then becomes a pupa, living within this resinous armor, leaving only two openings: one for breathing and one for excretion. Eventually, the pupa transforms into an adult, remaining immobile for a total of about eight weeks. By this time, the female lac insect remains still inside the resinous shield and begins to produce eggs. Resin production accelerates, and the shield expands to accommodate the increasing number of eggs. Meanwhile, the male sheds its skin, loses its sap-sucking mouthparts, and develops legs, antennae, and small wings. This allows the male lac insect to move and mate with the female to fertilize the eggs. Afterward, the female shrinks to allow light to penetrate the resin cover, and the eggs hatch into larvae, restarting the cycle. Inside the ovaries, there is a dark red liquid known as lac dye, similar to “cochineal,” which is commonly used as a food coloring. The places that cultivate lac insects wait until the eggs are about to hatch before scraping the branches for resin. Only a few female insects with eggs are kept for breeding for the next generation. Once the larvae are established on suitable plants, no further care is required. They simply wait for harvest season.
Lac Resin:
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Laccifer lacca |
Freshly scraped lac resin, still containing remnants of insects, tree bark, and the resin’s color, is called crude lac (or sticklac in industry jargon) and is very moist. Producers must dry it before bringing it to the local market to sell to buyers from manufacturing companies. In the workshop, the crude lac is crushed or ground, washed, and filtered to remove dirt, insect remains, and tree bark. It is then fanned and dried to form scales, ranging in color from dark red to pale yellow, known as seedlac. Seedlac contains 70% to 90% resin and 3% to 4% wax. Seedlac is then processed into lac resin, known as shellac. The formulation varies by region. During the entire production process, machinery may be used, or it can be done manually, depending on the workshop’s facilities. The best quality shellac is pale yellow, followed by dark orange, and then brownish varieties. Sometimes, chemicals are added to produce a whitish resin known as white lac.
Applications of Lac Resin:
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Vinyl Records |
Lac resin has been used since ancient times. Specifically in Vietnam, according to Dr. Ho Dac Duy, people in the North have used lac resin for tooth dyeing. The red color of vibrant carpets produced in Persia or India has been dyed with lac resin. In the late 19th century, 78 RPM records made with the winding machine “La voix de son maître” (featuring a dog sitting next to a horn) were manufactured using lac resin. In Vietnam, these records continued to be used in the 1950s and 1960s, often released by Asia Records (especially for Vọng cổ).
Lac Resin on the Market:
Lac resin is also used to produce coloring agents, dye foods, gloss fruits, coffee beans, and some other seeds. It is utilized in paint and varnish formulations and is found in hair spray. In industry, lac resin is used to make felt hats, and adding a little lac resin makes the felt stiffer and more upright. It is used as an adhesive to seal joints or gaskets, in the production of sealing wax, in printing inks, to coat the backs of high-standard playing cards, and white shellac, mixed with other chemicals, is used as a floor polish wax. In medicine, lac resin is used to create molds for dentures and to line containers used for storing urine for 24-hour tests, especially for diabetes patients.
Production of Lac Resin:
Lac insects are cultivated in India in the states of Bihar, Madhya Pradesh, West Bengal, Maharashtra, and Orissa, as well as in some areas of Thailand. The host plants for lac insects include Palas, Kusum, and Ber in India. In Thailand, lac insects are raised on robust plants in monsoon regions. Between 1956 and 1957, India alone exported 43,000 tons of lac resin. However, with the advent of synthetic resins (plastics) used in producing microgroove records (45 or 33.3 RPM) and especially in synthetic dyes, the use of lac resin declined. By 1989, the market for lac resin had significantly dwindled, nearly disappearing. However, when it was discovered that synthetic dyes contained toxic substances, lac resin, which is durable and non-toxic, experienced a revival.
Between 1995 and 1996, India exported nearly 9,000 tons of lac resin. The United States purchased 3,000 tons, Germany 1,500 tons, Indonesia over 1,300 tons, Canada 500 tons, Japan 190 tons, Singapore 95 tons, France 60 tons, and Russia and Australia each bought over 50 tons. The revenue generated was approximately 34 million USD. Cultivating lac insects is only challenging during the egg collection for the next breeding cycle; afterward, no further care for the lac insects is necessary. In Vietnam, if organized properly, this could create jobs for farmers during the rice off-season, increasing income without requiring significant capital investment. What do Northern farmers think about this?
