Lac

Lac is the scarlet resinous secretion of a number of species of lac insects, of which the most commonly cultivated is Kerria lacca.

Cultivation begins when a farmer gets a stick (broodlac) that contains eggs ready to hatch and ties it to the tree to be infested.[1] Thousands of lac insects colonize the branches of the host trees and secrete the resinous pigment. The coated branches of the host trees are cut and harvested as sticklac.

The harvested sticklac is crushed and sieved to remove impurities. The sieved material is then repeatedly washed to remove insect parts and other soluble material. The resulting product is known as seedlac. The prefix seed refers to its pellet shape. Seedlac which still contains 3–5% impurities is processed into shellac by heat treatment or solvent extraction.

The leading producer of lac is Jharkhand, followed by the Chhattisgarh, West Bengal, and Maharashtra states of India. Lac production is also found in Bangladesh, Myanmar, Thailand, Laos, Vietnam, parts of China, and Mexico.

Kerria-lacca
Lac tubes created by Kerria lacca
Shellac varities
Resin secreted by the female lac bug on trees is processed and sold as dry flakes.

Etymology

The word lac is derived from the Sanskrit word lākshā' (लाक्षा), which represents the number 100,000. It was used for both the lac insect (because of their enormous number) and the scarlet resinous secretion it produces. This resin has been used for making traditional and tribal bangles,[2] and still used as sealing wax by the India Post.[3] It is also used as wood finish, skin cosmetic and dye for wool and silk in ancient India and neighbouring areas.[4][5] Lac resin was once imported in sizeable quantity into Europe from India along with Eastern woods.[6][7]

Host trees

Pongamia pinnata
Pongam or honge (Millettia pinnata) is a native of India and grows in profusion, generally planted as avenue trees by the forest department. It is renowned for its shade and is well known in traditional uses for its medicinal properties. It is also grown as a host plant for lac insects. The tree is also one of the food plants for common cerulean (Jamides celeno).

Kerria lacca can be cultivated on either cultivated or wild host plants.

Estimated yields per tree in India are 6–10 kg for kusum, 1.5–6 kg for ber, and 1–4 kg for dhak.[9] The bugs' life cycles can produce two sticklac yields per year, though it may be better to rest for six months to let the host tree recover.[10]

Harvesting

Lac is harvested by cutting the tree branches that hold sticklac. If dye is being produced, the insects are kept in the sticklac because the dye colour comes from the insects rather than their resin. They may be killed by exposure to the sun.[9]

On the other hand, if seedlac or shellac is being produced, most insects can escape because less coloured pale lac is generally more desired.[9]

Uses

The use of lac dye goes back to ancient times. It was used in ancient India and neighbouring areas as wood finish, skin cosmetic and dye for wool and silk.[4][5][9] In China it is a traditional dye for leather goods. Lac for dye has been somewhat replaced by the emergence of synthetic dyes,[9] though it remains in use, and some juices, carbonated drinks, wine, jam, sauce, and candy are coloured using it.[11]

Lac is used in folk medicine as a hepatoprotective and anti-obesity drug. It is used in violin and other varnish and is soluble in alcohol. This type of lac was used in the finishing of 18th-century fowling guns in the United States.

Production levels

India exported significant amounts of sticklac derivatives, especially lac dye, from the 1700s to the late 1800s. Production declined as synthetic dyes emerged, and after the late 1940s, production of seedlac and shellac also declined due to replacement.[9]

In the mid-1950s, India annually produced about 50,000 tons of sticklac and exported about 29,000 tons of lac; by the late 1980s the figures were about 12,000 tons and 7,000 tons, respectively. By 1992–93, India's lac exports fell further to 4,500 tons. In the same period, Thailand's production increased somewhat, with annual lac exports of around 7,000 tons in the 1990s, mainly of seedlac. China exported only about 500 tons of shellac per year in the 1990s but produced more lac internally: 4,000-5,000 tons of sticklac and 2,000–3,000 tons of shellac in Yunnan province, with additional, smaller production in Fujian province. While India, Thailand, and China are the major lac producers, Bangladesh, Myanmar, Vietnam, and Sri Lanka also play small roles.[9]

Species

See also

  • Carmine (E120) – Another pigment extracted from an insect.
  • Lacquer – A product that was at one time made from lac, but in modern common usage now refers to a separate product with similar properties.
  • Shellac – A protective coating.

References

  1. ^ Derry, Juliane (2012). "Investigating Shellac: Documenting the Process, Defining the Product" (PDF). Project-Based Masters Thesis, University of Oslo. p. 27. Retrieved 3 July 2014.
  2. ^ "The art of making lac bangles.", Gaatha.com.
  3. ^ "The art of sealing.", itokri.com.
  4. ^ a b Franco Brunello (1973), The art of dyeing in the history of mankind, AATCC, 1973, ... The word lacquer derives, in fact, from the Sanskrit 'Laksha' and has the same meaning as the Hindi word 'Lakh' which signifies one-hundred thousand ... enormous number of those parasitical insects which infest the plants Acacia catecu, Ficus and Butea frondosa ... great quantity of reddish colored resinous substance ... used in ancient times in India and other parts of Asia ...
  5. ^ a b Ulrich Meier-Westhues (November 2007), Polyurethanes: coatings, adhesives and sealants, Vincentz Network GmbH & Co KG, 2007, ISBN 978-3-87870-334-1, ... Shellac, a natural resin secreted by the scaly lac insect, has been used in India for centuries as a decorative coating for surfaces. The word lacquer in English is derived from the Sanskrit word laksha. which means one hundred thousand ...
  6. ^ Donald Frederick Lach; Edwin J. Van Kley (1994-02-04), Asia in the making of Europe, Volume 2, Book 1, University of Chicago Press, 1971, ISBN 978-0-226-46730-6, ... Along with valuable woods from the East, the ancients imported lac, a resinous incrustation produced on certain trees by the puncture of the lac insect. In India, lac was used as sealing wax, dye and varnish ... Sanskrit, laksha; Hindi, lakh; Persian, lak; Latin, lacca. The Western word "lacquer" is derived from this term ...
  7. ^ Thomas Brock; Michael Groteklaes; Peter Mischke (2000), European coatings handbook, Vincentz Network GmbH & Co KG, 2000, ISBN 978-3-87870-559-8, ... The word "lacquer" itself stems from the term "Laksha", from the pre-Christian, sacred Indian language Sanskrit, and originally referred to shellac, a resin produced by special insects ("lac insects") from the sap of an Indian fig tree ...
  8. ^ Iwasa, S, 1997. Schleichera oleosa (Lour.) Oken. In Faridah Hanum, I. & van der Maesen, L.J.G. (Eds.): Plant Resources of South-East Asia No. 11. Auxiliary Plants. Prosea Foundation, Bogor, Indonesia. pp. 227-229.
  9. ^ a b c d e f g Green, C. L. (1995). "5: Insect Dyes". Non-Wood Forest Products 4: Natural colourants and dyestuffs. Rome: Food and Agriculture Organization of the United Nations. Retrieved 3 July 2014.
  10. ^ Derry, Juliane (2012). "Investigating Shellac: Documenting the Process, Defining the Product" (PDF). Project-Based Masters Thesis, University of Oslo. p. 28. Retrieved 3 July 2014.
  11. ^ Flinn, Angel (15 Aug 2011). "Shellac & Food Glaze". Gentle World. Retrieved 3 July 2014.

External links

Fond du Lac, Wisconsin

Fond du Lac () is a city in Fond du Lac County, Wisconsin, United States. The population was 43,021 at the 2010 census. The city forms the core of the United States Census Bureau's Fond du Lac Metropolitan Statistical Area, which includes all of Fond du Lac County (2000 population: 97,296). Fond du Lac is the 342nd largest Metropolitan Statistical Area (MSA) in the United States. The Fond du Lac MSA and the Beaver Dam (city), Wisconsin Micropolitan Statistical Area, form the larger Fond du Lac-Beaver Dam Combined Statistical Area.

Fond du Lac County, Wisconsin

Fond du Lac County is a county in the U.S. state of Wisconsin. As of the 2010 census, the population was 101,633. Its county seat is Fond du Lac. The county was created in the Wisconsin Territory in 1836 and later organized in 1844. Fond du Lac is French for "bottom of the lake", so given because of the county's location at the southern shore of Lake Winnebago.Fond du Lac County comprises the Fond du Lac, Wisconsin Metropolitan Statistical Area.The Holyland region is in northeastern Fond du Lac County.

Jura (department)

Jura (French pronunciation: ​[ʒyʁa]) is a department of Bourgogne-Franche-Comté in the east of France named after the Jura Mountains.

Lac La Biche, Alberta

Lac La Biche ( LAK lə BISH) is a hamlet in Lac La Biche County within northeast Alberta, Canada. It is located approximately 220 km (140 mi) northeast of the provincial capital of Edmonton. Previously incorporated as a town, Lac La Biche amalgamated with Lakeland County to form Lac La Biche County on August 1, 2007.

Lac operon

The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available through the activity of beta-galactosidase. Gene regulation of the lac operon was the first genetic regulatory mechanism to be understood clearly, so it has become a foremost example of prokaryotic gene regulation. It is often discussed in introductory molecular and cellular biology classes for this reason. This lactose metabolism system was used by François Jacob and Jacques Monod to determine how a biological cell knows which enzyme to synthesize. Their work on the lac operon won them the Nobel Prize in Physiology in 1965.Bacterial operons are polycistronic transcripts that are able to produce multiple proteins from one mRNA transcript. In this case, when lactose is required as a sugar source for the bacterium, the three genes of the lac operon can be expressed and their subsequent proteins translated: lacZ, lacY, and lacA. The gene product of lacZ is β-galactosidase which cleaves lactose, a disaccharide, into glucose and galactose. lacY encodes Beta-galactoside permease, a membrane protein which becomes embedded in the cytoplasmic membrane to enable the cellular transport of lactose into the cell. Finally, lacA encodes Galactoside acetyltransferase.

It would be wasteful to produce enzymes when no lactose were available or if a preferable energy source such as glucose were available. The lac operon uses a two-part control mechanism to ensure that the cell expends energy producing the enzymes encoded by the lac operon only when necessary. In the absence of lactose, the lac repressor, lacI, halts production of the enzymes encoded by the lac operon. The lac repressor is always expressed unless a co-inducer binds to it. In other words, it is transcribed only in the presence of small molecule co-inducer. In the presence of glucose, the catabolite activator protein (CAP), required for production of the enzymes, remains inactive, and EIIAGlc shuts down lactose permease to prevent transport of lactose into the cell. This dual control mechanism causes the sequential utilization of glucose and lactose in two distinct growth phases, known as diauxie.

Lake Chad

Lake Chad (French: Lac Tchad) is a historically large, shallow, endorheic lake in Africa, which has varied in size over the centuries. According to the Global Resource Information Database of the United Nations Environment Programme, it shrank by as much as 95% from about 1963 to 1998, but "the 2007 (satellite) image shows significant improvement over previous years." Lake Chad is economically important, providing water to more than 30 million people living in the four countries surrounding it (Chad, Cameroon, Niger, and Nigeria) on the edge of the Sahara. It is the largest lake in the Chad Basin.

Lake Geneva

Lake Geneva (French: lac Léman [lak lemɑ̃] or le Léman [lə lemɑ̃], rarely lac de Genève [lak də ʒ(ə)nɛv]; German: Genfersee [ˈɡɛnfərˌzeː]) is a lake on the north side of the Alps, shared between Switzerland and France. It is one of the largest lakes in Western Europe and the largest on the course of the Rhône. Of it 59.53% (345.31 km2 or 133.32 sq mi) comes under the jurisdiction of Switzerland (cantons of Vaud, Geneva, and Valais), and 40.47% (234.71 km2 or 90.62 sq mi) under France (department of Haute-Savoie).

Lake Ontario

Lake Ontario is one of the five Great Lakes of North America. It is surrounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the American state of New York, whose water boundaries meet in the middle of the lake. Ontario, Canada's most populous province, was named for the lake. Many of Ontario's most populous cities, including Toronto, Canada's most populous city, and Hamilton, are on the lake's northern or western shores. In the Huron language, the name Ontarí'io means "Lake of Shining Waters". Its primary inlet is the Niagara River from Lake Erie. The last in the Great Lakes chain, Lake Ontario serves as the outlet to the Atlantic Ocean via the Saint Lawrence River. It is the only Great Lake not to border the state of Michigan.

Lake St. Clair

Lake St. Clair (French: Lac Sainte-Claire) is a freshwater lake that lies between the Canadian province of Ontario and the U.S. state of Michigan. It was named after Clare of Assisi, on whose feast day it was navigated and christened by French Catholic explorers in 1679. It is part of the Great Lakes system, and along with the St. Clair River and Detroit River, Lake St. Clair connects Lake Huron (to its north) with Lake Erie (to its south). It has a total surface area of about 430 square miles (1,100 km2) and an average depth of just 11 feet (3.4 m); to ensure an uninterrupted waterway, government agencies in both countries have maintained a deep shipping channel through the shallow lake for more than a century.

Lancelot

Lancelot du Lac (meaning Lancelot of the Lake), alternatively also written as Launcelot and other spellings, is one of the Knights of the Round Table in the Arthurian legend. He typically features as King Arthur's greatest companion, the lord of Joyous Gard and the greatest swordsman and jouster of the age – until his adulterous affair with Queen Guinevere is discovered, causing a civil war which was exploited by Mordred and brings about the end of Arthur's kingdom.

His first appearance as a main character is in Chrétien de Troyes' poem Lancelot, the Knight of the Cart, written in the 12th century. Later, his exploits were expanded upon in the Prose Lancelot, which was further expanded upon for the vast Lancelot-Grail cycle. There, his and Lady Elaine's son, Galahad, becomes an even more perfect knight and achieves the Holy Grail.

Library and Archives Canada

Library and Archives Canada (LAC; French: Bibliothèque et Archives Canada) is a federal institution tasked with acquiring, preserving and making Canada's documentary heritage accessible. It is the fourth biggest library in the world. LAC reports to Parliament through Pablo Rodríguez, the Minister of Canadian Heritage since August 28, 2018.

List of airports in Quebec

This is a complete list of airports, water aerodromes and heliports in the Canadian province of Quebec.

National Register of Historic Places listings in Lac qui Parle County, Minnesota

This is a list of the National Register of Historic Places listings in Lac qui Parle County, Minnesota. It is intended to be a complete list of the properties and districts on the National Register of Historic Places in Lac qui Parle County, Minnesota, United States. The locations of National Register properties and districts for which the latitude and longitude coordinates are included below, may be seen in an online map.

There are 10 properties and districts listed on the National Register in the county. A supplementary list includes three additional sites that were formerly on the National Register.

This National Park Service list is complete through NPS recent listings posted August 9, 2019.

Quebec City

Quebec City ( (listen) or ; French: Québec [kebɛk] (listen); French: Ville de Québec, Western Abnaki: Kephek), officially Québec, is the capital city of the Canadian province of Quebec. The city had an estimated population of 531,902 in July 2016 (an increase of 3.0% from 2011), and the metropolitan area had a population of 800,296 in July 2016 (an increase of 4.3% from 2011). It is the second largest city in Quebec after Montreal, and the seventh largest metropolitan area and eleventh largest city in Canada.

The Algonquian people had originally named the area Kébec, an Algonquin word meaning "where the river narrows", because the Saint Lawrence River narrows proximate to the promontory of Quebec and its Cape Diamant. Explorer Samuel de Champlain founded a French settlement here in 1608, and adopted the Algonquin name. Quebec City is one of the oldest European cities in North America. The ramparts surrounding Old Quebec (Vieux-Québec) are the only fortified city walls remaining in the Americas north of Mexico. This area was declared a World Heritage Site by UNESCO in 1985 as the "Historic District of Old Québec".The city's landmarks include the Château Frontenac hotel that dominates the skyline and the Citadelle of Quebec, an intact fortress that forms the centrepiece of the ramparts surrounding the old city and includes a secondary royal residence. The National Assembly of Quebec (provincial legislature), the Musée national des beaux-arts du Québec (National Museum of Fine Arts of Quebec), and the Musée de la civilisation (Museum of Civilization) are found within or near Vieux-Québec.

Rouyn-Noranda

Rouyn-Noranda (2011 population 41,012) is a city on Osisko Lake in the Abitibi-Témiscamingue region of Quebec, Canada.

The city of Rouyn-Noranda is a coextensive with a territory equivalent to a regional county municipality (TE) and census division (CD) of Quebec of the same name. Their geographical code is 86.

Saguenay–Lac-Saint-Jean

Saguenay–Lac-Saint-Jean (French pronunciation: ​[saɡ.nɛ.lak.sɛ̃.ʒɑ̃], local pronunciation: [saɡ.ne.lak.sẽ.ʒã]) is a region in Quebec, Canada. It contains the Saguenay Fjord, the estuary of the Saguenay River, stretching through much of the region. It is also known as Sagamie in French, from the first part of "Saguenay" and the last part of "Piekouagami", the Innu name (meaning "flat lake") for Lac Saint-Jean, with the final "e" added to follow the model of other existing region names such as Mauricie, Témiscamie, Jamésie, and Matawinie. [1] The name Saguenay is possibly derived from the Innu word "Saki-nip" which means "where water flows out". [2] [3] With a land area of 98,710.11 km2 (38,112.19 sq mi), the Saguenay–Lac-Saint-Jean is, after the Nord-du-Québec and Côte-Nord regions, the third-largest of Quebec regions in the area.

This region is bathed by two major watercourses, Lac Saint-Jean and the Saguenay River, both of which mark its landscape deeply and have been the main drives of its development in history. It is also irrigated by several other large watercourses. Bordered by forests and mountainous massifs, the southern portion of the region constitutes a fertile enclave in the Canadian Shield called the Saguenay Graben. Both the scenery and the cultural sites and activities of Saguenay–Lac-Saint-Jean attract tourists every year. Lac Saint-Jean is a popular vacation destination in the summer for residents of the more urban regions of Quebec.

The region is considered the heartland of the Quebec sovereignty movement.

The beauty of the region can be seen in the 1991 film Black Robe, directed by Bruce Beresford.

Shellac

Shellac is a resin secreted by the female lac bug, on trees in the forests of India and Thailand. It is processed and sold as dry flakes (pictured) and dissolved in alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and wood finish. Shellac functions as a tough natural primer, sanding sealant, tannin-blocker, odour-blocker, stain, and high-gloss varnish. Shellac was once used in electrical applications as it possesses good insulation qualities and it seals out moisture. Phonograph and 78 rpm gramophone records were made of it until they were replaced by vinyl long-playing records from the 1950s onwards.

From the time it replaced oil and wax finishes in the 19th century, shellac was one of the dominant wood finishes in the western world until it was largely replaced by nitrocellulose lacquer in the 1920s and 1930s.

Aspects
of insects
in culture
Economic
entomology
Pioneers
Concerns
Related
Categories,
templates

Languages

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.