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Essay on Lac Culture
Essay Contents:
- Essay on the Introduction to Lac Culture
- Essay on the Life History of Lac Culture
- Essay on the Requirements for Production of Lac
- Essay on the Science of Lac Culture
- Essay on the Composition and Uses of Lac
- Essay on the Lac Industry in India
- Essay on the Economic Importance of Lac
Essay # 1. Introduction to Lac Culture:
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Lac is the sticky resinous substance secreted by a tiny variety of insects. Use and culture of lac and lac products began in India as early as 1200 B.C. The word lac is derived from the Hindi word lakh, which means hundred thousand indicating the large number of insects required to produce recognizable quality of lac. About 17,000 to 90,000 insects are required to produce one pound of lac.
The lac has been referred in ancient Sanskrit works viz., Atharva-Veda and was called as ‘Luxa’. It is mentioned in Mahabharata that ‘Luxa Griha’ was made up of lac, which was prepared by Kaurava for Pandavas.
Abul Fazal (1590) in his famous book ‘Ain-I-Akbari’ has mentioned in detail about the lac industry in India. Mahdihassan (1950, 1952), has referred about the lac insect and its products in China. The first scientific reference regarding the lac and lac insect is the report of Kerr and Glover in 1782. Subsequently, much work has been done by various workers on the organization, distribution, taxonomy, host plants, culture, production, enemies, chemistry and technology.
Lac is secreted by a coccid insert called Lacifera laca. The insects are cultured in large scale by providing them their specific host plants, nursing and protecting them from their natural enemies. The science of commercial culture of lac insects is called lac culture.
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Three products from lac insects, viz., the lac-dye, lac-wax and lac (resin) have been items of trade and commerce.
Distribution:
The lac insect is widely distributed in India. India has its monopoly on the production of lac. Other countries like Africa, Australia, Brazil, Burma, Sri Lanka, China, Formosa, France, W. Germany Japan, Malaya, Nepal, Spain, Thailand, Turkey, U.S.A. and some other also produce lac. But in Thailand, Malaya, Burma and Nepal the lac producing industries are increasing day-by-day. Thailand has become the main competitor of India in export of lac.
In India major lac producing places is Assam (Kashi Hills), Bengal (Calcutta, Jangipur, Murshidabad, Mathrapur, Malda). Bihar (Manbhum, Palamau, Ranchi, Santhal Pragana), Delhi, Gujarat, Hyderabad, Kashmir, Madhya Pradesh (Damoh, Champa, Bilaspur, Rewa, Umaria). Chennai, Coimbatore, Mysore, Orissa (Cuttack, Mayurbhanj). Punjab (Hoshiarpur, Shahpur), Rajasthan (Indergarh, Kota, Jaipur, Jhallawar, Karauli), and Uttar Pradesh (Ghazipur, Mirzapur, Agra) etc.
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The females secrete a resinous substance, which is a great commercial importance. The females are apterous and stationary. The body of the female is highly degenerate with vestigial antennae. The larval females have eyes, antennae, and thoracic legs. They make small movements and metamorphose to the adult.
The stationary habit of the adult female is attributory to its degenerate nature. The shape of the body is irregularly rounded. The maturing female secretes the resinous mass from the dermal lac of resin glands distributed throughout the body except at the anal and tubercular region. The lac secreted will form a lac cell inside which the female gets enclosed.
The males are large and better developed than the females. The typical body parts of an insect viz. head, thorax and abdomen can be distinguished in adults males. Males are red to reddish-brown in colour.
The head bears a pair of well-developed and hairy antennae, a pair of compound eyes. 3 pairs of slender thoracic legs are present. Mouthparts are highly degenerate therefore the males are not able to feed. The males live for 60-90 hours and can fertilize about 50 females during its short span of life. Both winged and wingless males occur. The lac-cell of the male is elongate with a pair of branchial openings. The male comes out of the cell through another opening at the posterior end.
Essay # 2. Life History of Lac Culture:
The deep crimson coloured female after producing the required amount of lac stops feeding and the body of the female shrinks considerably. It lays about 300-400 small, rounded eggs at a time and the female die leaving an encrustation full of eggs. The eggs after sometimes change their colour and hatching takes place after sometimes. Hatching is governed by the temperature and humidity. Generally first brood comes in October or November.
The larvae emerge in a large number and come out of the encrustation. These are small about .5 mm in size, red or pinkish red. They have a brood middle region and tapering ends and resemble a pear shaped body. They are provided with piercing and sucking type of mouthparts and ocelli. The thorax and abdomen are well developed.
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The first instar larvae are very sluggish and crawl a short distance only. They move in form of a big crowd so it is named as “Swarming”. They prefer a newly emerged, soft and succulent shoot where they can feed easily. The larvae settle together in a large number in close association with each other. Sometimes they are so close that the twig is not seen.
They feed upon the sap and secrete a pink coloured resin like substance from their dermal glands. This becomes hard when comes in contact with air and is known as lac. Lac deposition is done in all parts of the body except the mouthparts, spiracles and anal pores. The so formed envelop is now called “Cell” which protects the larva and all the post embryonic stages are completed inside the cell.
The larvae moult thrice inside the cell and become sexually mature. The male and females are almost alike but they become distinct within two weeks. They can be well marked by its elongated cell. It contains two opening at the anterior end. Female cell is almost rounded with irregular margin and possesses 6 holes through which hair like fibers may emerge.
The male cell produces winged and wingless males, which are active and come out of the cell, walk over the lac crustation of the female and fertilize the female. Both males are capable of fertilizing the female but the winged males move faster than the wingless males. They possess well developed legs, wings and other appendages.
Whereas the female larva after three moultings becomes sexually mature, but the appendages are reduced. The sexually mature female gets fertilized through the anal opening present in the cell. It grows very fast and produces more resin like substances, white, thin, fibrous, hair like processes come out of the thread and give a white appearance.
The females live longer than males but never come out of their cells. Depending upon the completion of life cycle stages and production of lac generally two crops are produced in a year. One is known as Baishakhi and other Kartiki crop. The insects reared on Kusum produce Kusumi lac, which also produce two crops in a year the Aghani and Jethi.
The period of crop depends upon the climatic conditions, rainfall temperature and humidity as well as the type of host plant available. Various types of plants have different period of defoliation and emergence of new leaves. So they directly govern the production of lac, and maturation of postembryonic stages.
Generally eggs are laid in summer and winter seasons, which get matured within stipulated period and produce lac in two seasons.
Essay # 3. Requirements for Production of Lac:
Production of lac is subjected to a variety factors:
1. Climatic Factors:
A variety of environmental cues like hot wind, high rainfall, draught, rise in temperature and humidity and extreme chill weather affect the development of the insect and production of lac. Foggy weather kills the newly emerged males.
2. Predators and Parasites:
Besides the environmental factors there is a long list of predators, parasites and non-traditional pests, which cause serious damage to the lac crop. Rats, squirrels, bats and flying foxes feed upon the lac insect and damage the deposition flying boxes and bats feed upon the newly emerged males and females as well as scratch out the lac deposition.
The lepidopteron moths like Eublemma amabilis and Hokocera pulverea lay eggs near the lac encrustations and they are in abundance in July and August. The larvae eat upon the injects and damage the lac deposition. There are certain chalcid parasites like Tetrastichus purpureus. Coccophagus tschirchii lay eggs on the lac insects and reduce the production.
Host Plants:
The lac insects have more than one host plant. The selection of suitable host plant for the cultivation of lac is of much importance. To establish the lac industry one should know well about the topographic and climatic conditions for the growth of host plants suitable for that particular region, Brun (1958) has mentioned that 113 varieties of host plants are found in the geographical Indian regions including Pakistan and Burma.
Out of these 113 host plants only 14 are very common in India, which are as follows:
The quality of lac is directly related with the quality of host plant. So far, no artificial product has been able to replace the lac. Khair, Kusum and Babul give better quality of lac when sown directly in the field. But Palas, Ber and Ghont give good crop when they are first sown in nursery and then transplanted to the lac-growing field. Palas and Ber produce a particular type of lac, which is called as ‘Kusumi Loc’.
Essay # 4.
Science of Lac Culture:
For commercial production of lac, culture techniques are resorted. Lac Culture involves proper care of lac insects and their host plants.
The methodologies involved in lac culture are:
1. Introduction of Lac Larva on Host Plant for Infection.
2. Care of Lac Growth.
3. Recovery of Lac Resin.
4. Processing of Lac Resin.
1. Introduction of Lac Larva on Host Plant for Infection:
The host plant specific to lac insects are cultivated in selected areas as the first step towards lac culture. The trees must reach a desirable height before inoculating the lac insects.
Large and mature colonies of lac are selected which may contain recently laid egg masses. This collection is called brood lac. Brood lac can be noticed as thick encrustations on tree twigs especially on the green or tender branches. The brood lac is collected enmass along with the twig piece on which the colony has settled. They are then tied to the tender branches of the host plant on which culture is intended.
The brood may be fixed to the host tree either in a longitudinal fashion, or in a lateral manner or interlaced between many branches. The lac insects will slowly migrate to fresh parts of the host plants, and settle to form colonies. There they undergo reproduction and the resinous lac is deposited.
2. Care of Lac Growth:
Close and constant watch must be maintained on the progress of lac culture as the change of substrate may make the insects vulnerable.
The host tree must be healthy enough to supply the nutrient plant sap on which the insects live. Predators of the lac insect like white moth and grey moth should be completely eliminated. Higher animals like squirrels, rats, and birds also destroy lac depositions. Parasites and other natural enemies of insects must not be allowed to settle on the lac colonies. Equally important is the care of the host plant.
3. Recovery of Lac Resin:
The insects normally complete two life cycles in a year. The continuous secretion of lac resin on the twig will lead to the formation of the encrustations few inches thick. This encrustation on the tree twig is called lac stick. The lac sticks are separated from the host plant and resin is scrapped off using a sharp knife. Usually the lac sticks are recovered just after egg laying.
4. Processing of Lac Resin:
The scrapped lac may contain dirt and plant parts. It is thoroughly washed in water and air-dried. The dried material is called lac seed. The lac seed is melted in heat and filtered. To this lac liquors added other colouring agents, preservatives or hardening chemicals. The processed product is commercially known as shell lac.
It takes about 5-6 months for the ripening of lac, crop from inoculation time. In a year the lac insects complete the life cycle twice.
There are two strains of lac crops in India:
1. Rangeeri, where the host plant is infected during October-November months and the crop reaped during the months of June-July. This crop is more common in Karnataka.
2. Kusumi where infection is performed during June July months and the crop reaped during October-November months. This is usually attempted in North Indian states.
Essay # 4.
Composition and Uses of Lac:
Composition of Lac:
The natural lac is always contaminated with sand, dirt dead insects and bark of the twig; dried leaves, pollen and other foreign substances may be attached with the lac. The pure industrial lac is produced after cleaning and filtering the natural lac. A through washing and filtering of lac produces seed lac, which is heated and filtered.
The filtered lac now known as shellac is almost pure form of the lac. This type of lac may be obtained by dissolving the seed lac into alcohol and then drying. The lac contains resin, dye and hard wax. A small amount of water and mineral is also found in lac. Resin 60-85%, dye 2-10%, wax 6%, albuminous protein 5-8%, and minerals 6-7% and water 3-4%.
Use of Lac:
Lac contains high concentration of resin, moderate quantities of sugar, salts, proteins, liquid wax, Organic oils and traces of alkaloids and insect and plant tissues.
Lac is used as an adhesive base in many chemical preparations due to its sticky nature. It is used as an ingredient in plastics for making toys, vessels, gramophone records etc. Lac is used in the manufacture of varnishes, paints, and coating cable insulations.
Essay # 6. Lac Industry in India:
India produces nearly 30,000 tonnes of lac, out of this about 85% is exported to outside, earning us a foreign exchange of about Rs.18 crores annually. The establishment of Indian lac Research Institute in Bihar by ICAR has boosted up the research and culture of lac. Bihar (55%) Madhya Pradesh (20%) West Bengal (10%) and Maharashtra (8%) are the important states promoting lac culture and lac industry in India.
India used to produce about 97 per cent of the total lac output in the world but at present it has come down to 50-60 per cent. The cultivation of lac has been good source as an earner of foreign currency. About 50 per cent of the total lac produced in India is obtained from Chhotanagpur area. States like Orissa, Punjab, Madhya Pradesh, W. Bengal, Uttar Pradesh, Gujarat, Rajasthan, Assam etc., are increasing the production of lac now a days.
On a very small level lac producing is also reported from Delhi and Kashmir. The average yearly yield of lac in India is about 15,000 metric tons. A lac research institute ‘Indian Lac Research Institute’ Namkum, Ranchi had been established in 1925 which is producing good quality of white lac.
The Indian white lac is supposed to be better than red or other coloured lac because they produce stain or spots at places where they are kept. This is mostly small scale industry with around 350 factories, mostly located in Bihar. In Mirzapur district alone there are about 40 factories. Out of total lac produced in India about 85 to 95 percent is exported specially to Britain, U.S.A., Russia and West Germany.
Essay # 7. Economic Importance of Lac:
In 19th century lac dye was in more use than lac resin. Presently due to availability of a better and cheaper annaline dyes the use of lac as a dye has been discarded. The manifest uses of lac is one of the Nature’s standing gifts.
The various used to which it is put are:
1. It is utilized in the preparation of gramaphone records. Previously this industry utilized major part of the lac produced annually. But now a days to a great extent plastic is being used in this trade.
2. It is to utility of Jewellers and Goldsmiths who use lac a filling material in the hollows in gold ornaments like bracelets, armlets and necklaces etc.
3. It is an essential gradient used extensively for making polishes, paints and varnishes for finishing wooden as well as metal furniture’s and doors etc.
4. It is utilized for the preparation of toys, buttons, in pottery and artificial leather.
5. It is used in the manufacture of photographic material, lithographic ink and for stiffening felt and hat materials.
6. It is used as an insulating material for electrical goods.
7. It is also used in confectionary trade as anti-fowling for applying on ship bottom, grinding stone industry and for ammunition and fire-works.
8. Last but not the least used commonly as sealing wax.
Thus, it is of great use and considered to be as one of the cash crops for the cultivators and also to the Government as source of foreign exchange earners which amount to crores of rupees annually.