Introduction To Lac & Lac Culture
Introduction To Lac & Lac Culture
Introduction To Lac & Lac Culture
Department of Forest Biology & Tree Improvement Faculty of Forestry Birsa Agricultural University, Kanke, Ranchi-834 006 (Jharkhand)
May, 2011
Forward
he compilation Introduction to Lac and Lac Cultivation is praiseworthy & will serve as a reference for undergraduate
students of Agriculture and Forestry Faculty. Lac is a unique commodity as it is probably the only known resin of animal origin. Lac insects settle closely on the twigs of Palas, Ber or Kusum, suck the plant sap and grow to form encrustations. Lac insects yield resin, lac dye and lac wax. Improvement in health and nutrition of host plants and scientific methods of rearing the insects is essential for sustained returns from lac cultivation. With increasing demand of Aleuritic acid (a constituent of acid of shellac) in the world market as an ingredient of perfumes and pharmaceuticals, further studies on lac culture has become essential. I congratulate the author for his sincere efforts. Place : BAU, Ranchi Date : 01-05-2011
A.K. Sarkar
Dean (Agriculture)
Dr.A. Bhattacharya
Principal, Scientist & Head
Message
I
have gone through the book entitled introduction to Lac and Lac Culture Writen by Dr. Sailesh Chattopadyay, Faculty of Forestry, Birsa Agriculture University, Ranchi. The book deals with basics of Lac Culture in simple language. I confirm that it would be a valuable and useful book for the students and scientists associated with Lac Culture.
(A. Bhattacharya)
Acknowledgement
L
ac has been one of the important non-wood forest produce being utilized by the human society since time immemorial and lac farming provides subsidiary income to mainly poor subsistence level tribal farmers in the forest tracts of the country. The practices of lac culture are getting expanded in different regions of newly created Jharkhand state and necessity of a comprehensive account of Lac culture was strongly felt by all concerned. The present manual will be very useful for students, teachers and research workers concerned with lac culture. I express my appreciation to Dr. Bangali Baboo, ex-Director, Indian Institute of Natural Resins and Gums (ICAR) and present National Director (NAIP) at ICAR, New Delhi for his support, advice and helpful suggestions in writing the manual. I convey my regards to Dr. N. N. Singh, Honble Vice Chancellor, Birsa Agricultural University for rendering his clarity of thought in the fruitful execution of the work. I wish to express my indebtness to Dr. A. K. Sarkar, Dean, Faculty of Agriculture, Dr. S. K. Singh, Dean, Faculty of Forestry, Dr. B.N.Singh, Director Research, Dr. Balraj Singh, Dean P.G.s. -cum-D.R.I., and Dr. S.M. S. Quli, Head Department of Forest Biology and Tree Improvement for their support and encouragement in various ways for bringing out this publication. Sincere thanks are also due to Sri Amit and Sri Imtiaj for taking painful job of typing the manuscript. This publication has been made out of ICAR Development grant with whole hearted technical as well as moral support of Dr. A.K. Sarkar, Dean (Agriculture).
(Sailesh Chattopadhyay)
CONTENTS
INTRODUCTION Why Lac Cultivation History of lac and its organization WHAT IS LAC? 05 Ari and Phunki Lac Lac and its forms Composition of Lac Properties of Lac Uses of Lac LAC HOSTS 08 Area wise utilization of lac hosts Essential characteristics of lac hosts LAC PRODUCTION in India 10 STRAINS OF LAC AND LAC CROPS 10 LIFE HISTORY OF LAC INSECT 12 LOCAL CULTIVATION PRACTICES OF LAC 14 SCIENTIFIC METHOD OF LAC CULTIVATION 15 Selection of suitable host plant Selection of suitable site for lac cultivation Coupe system Preparation of feeding ground for lac insect Pruning operation Objectives of pruning Types of pruning Pruning time Pruning instruments Collection of brood lac Selection of brood lac Inoculation of brood lac Punki removal Harvesting ENEMIES OF LAC INSECTS 21 Vertebrate enemies Insect enemies Microbial flora Lac Cultivation Vis a Vis environmental economy conservation and rural 26
Page No. 01
ac is a natural resinous substance of profound economic importance in India. It is the only resin from animal origin lending itself to diverse applications e.g. as a protective and decorative coating in the form of thin films, adhesives and plastics. It makes a small but significant contribution to the foreign exchange earning of the country, but the most important role that the lac plays in the economy of the country is that roughly 3-4 million tribal people, who constitute the socioeconomically weakest link of Indian population earn a subsidiary income from its cultivation. India is the major producer of lac, accounting for more than 50% of the total world production. It virtually held a monopoly in the lac trade during the period of the world war-I, producing nearly 90% of the worlds total output. Today an average of about 20 -22 thousand tons of stick lac (raw lac) is produced in the country per year. Most of the lac produced in India is from homestead land and wasteland. Usually host trees standing on rayyati lands are used for lac cultivation and in some areas trees on Government land are taken on lease or rental basis.
The Indian Lac Research Institute (I.L.R.I.) was taken over by the Indian Council of Agriculture Research (I.C.A.R.) in 1966. Responding to the opening up of economic policies, globalization of industries and agricultural enterprises, the Indian Lac Research Institute ( I.L.R.I. ) has undergone a structural change and its priorities have been redefined, widening the scope and mandate of the institute. Besides research and development on all aspects of lac; processing and product development of other natural resins and gums have been brought under the ambit of research. Therefore, ILRI has been upgraded as Indian Institute of Natural Resins and Gums ( I.I.N.R.G. ) w.e.f. September 20, 2007. An Advisory body viz. the Indian Lac Development Council (I.L.D.C.) was also constituted by Govt. of India to give the due representation to the lac growing states and other interested in lac cultivation and its trade. The Directorate of Lac Development was transferred to the Ministry of Environment & Forests, in January, 1985. Later the Directorate of Lac Development was merged with Forest Research Institute (F.R.I.), Dehradun with effect from July, 1987 under the same ministry due to re-organization of subordinate and field officers of Ministry. Presently the Institute of Forest Productivity (Ex-Directorate of Lac Development), Ranchi is directly functioning under Indian Council of Forestry Research & Education (I.C.F.R.E.), Dehradun. The main functions of the Institute of Forest Productivity for Lac development are as follows :1. 2. 3. 4. 5. 6. To collect and compile various statistical data on lac concerning production, prices, internal consumption, export, dispatches etc. for use of government departments. To forecast and assess lac production in the country. To maintain regionally located Nucleus Brood Lac Farms for demonstration of improved methods of lac cultivation and supply of quality brood-lac to the villagers and user agencies. To maintain liaison between Central and State government, concerning lac development work. To render technical advice to the State government & other organizations on planning of lac cultivation, marketing, exports etc. To maintain an air-condition godown meant for storing shellac, seed lac etc. at Kolkata (West Bengal) which has been leased out to Central Warehousing Corporation
Indian Lac Research Institute (I.L.R.I.) came into existence as a result of the recommendation of a two member committee comprising of Mr. H.A.F. Lindsay and Mr C.M.Harlow appointed early in 1920 by the then Govt of India to enquire into the conditions of the Indian Lac trade and suggest measures for its all-round improvement. The report of the committee was published in 1921. They had recommended, besides other aspects, for intensive cultivation by significantly tested methods for sustained lac production. In view of this suggestion, the then lac merchants organized themselves into a private registered body ,the Indian Lac Association for Research. The Association acquired land from the provincial government and the foundation of the Indian Lac Research Institute (I.L.R.I.) was laid on Sep.20, 1924. It started functioning under the Founder Director, Mrs. Dorothy Norris. In 1930, on the recommendation of the Royal Commission for Agriculture, the Indian Lac Cess Act was passed by the Central Legislature. Under this Act, the Govt of India constituted the Indian Lac Cess Committee which took over the Institute from Lac Association in 1931. After the Second World War, the First & Second Review Committees set up in 1951 and 1956, formed broad research programmes with equal emphasis on fundamental and applied research. During the period, four Regional Field Research Stations (R.F.R.S.) were set up at Jhalda (West Bengal), Damoh, Umaria (Madhya Pradesh) and Mirzapur (Uttar Pradesh) to take up regional problems. Later, Regional Testing Laboratories were also established to support lac manufacturers for quality control of different types of lac manufactured by them. These were set up at Gondia (Maharashtra), Jhalda (West Bengal) in 1959, at Balrampur (West Bengal) and Daltonganj (erstwhile Bihar) in 1961 and at Namkum, Ranchi (erstwhile Bihar) in 1962. Indian Council of Agricultural Research (I.C.A.R.) took over the administrative control of the Institute on 1st April,1966, with the abolition of the Lac Cess Committee on this day. The Institute was strengthened and reconstituted in December 1971, based on the recommendation of Sheshadri Committee, into five devisions, viz. Entomology, Chemistry, Agronomy & Plant Genetics, Technology and Extension.
MANDATE
The mandate of the Institute for Lac Development is : (i) (ii) To develop lac culture technologies, adopting existing or genetically improved lac insects and lac hosts. To develop lac processing techniques for the industry.
(iii) To conduct researches for diversification of lac utilization leading to pilot plant demonstration. (iv) To transfer the technologies to farmers and entrepreneurs. (v) To act as a repository of information on lac production, processing and utilization.
What is lac?
Lac is a natural, biodegradable, non-toxic, odourless, tasteless, hard resin and non-injurious to health. Lac is, in fact, a resinous protective secretion of tiny lac insect, Kerria lacca (Kerr.) which belongs to the family Tachardidae in the super family Coccoidea of the order Hemiptera. The lac insect is a pest on a number of plants both wild as well as cultivated. The tiny redcoloured larvae of lac insect settle on the young succulent shoots of the host plants in myriads and secrete a thick resinous fluid which covers their bodies. The secretion from the insects form a hard continuous encrustation over the twigs. The encrusted twigs are harvested and the encrusted twigs scraped off, dried and processed to yield the lac of commerce which is regarded as Non Wood Forest Product (NWFP) of great economic importance to India.
: :
Button lac
Garnet lac
Bleached lac
Seed lac
Shellac
Button lac
Garnet lac
COMPOSITION OF LAC
The major constituents of stick lac or crude lac are resin, sugar, protein, soluble salt, coloring matter, wax, volatile oils, sand, woody matters and insect bodies. The resin is always associated with an odoriferous principle, a wax and a mixture of three dyes. Removal of both wax and dye results in a marvelous colourless and transparent resin having all the characteristic properties of the resin. Chemical analysis has revealed that the resin is made of at least six major chemical components of different molecular complexities. The building blocks of lac are mainly hydroxyaliphatic and sequiterpenic acids which are present in the proportion of 50:50. The basic blocks are however aleuritic and jalaric acids. The former is 9, 10, 16 trihydroxy palmitic acid and the later adihydroxymonocarboxylic sesquiterpenic acid having an aldehyde function. Composition of stick lac
68% 6% 1% 25%
: It is an ester complex of long chain hydroxy fatty acids and sesquiterpenic acid. : It is an anthraquinone derivative. : It is the mixture of higher alcohol, esters, acids and hydrocarbons.
Properties of lac
The important properties of lac are as follows : (i) (ii) (iii) (iv) (v) (vi) (vii) Soluble in alcohol and weak alkalis Capacity of forming uniform durable film. Possess high scratch hardness Resistance to water Good adhesive nature Ability to form good sealers, undercoat primers. Capacity to allow quick rubbing with sandpaper without slicking or gumming.
No other single resin, both natural or synthetic, possess so many desirable properties and so lac is also termed as multipurpose resin.
Uses of lac:
Because of its unique combination of properties, lac finds a wide variety of application in paint, electrical, automobile, cosmetic, adhesive, leather, wood finishing and other industries. Earlier about half of the total output was consumed in gramophone industry. Lac has long been in use both for decorative and lacquers of various kinds and insulating varnishes. It is usually used as a first coating on wood to fill the pores and also applied to seal knots likely to exude resin and disfigure or spoil finished paint work. Lac is used in manufacture of glazed paper, printing and water proofing inks, lac bangles, dry mounting tissue paper, dental plates and optical frames. It is also used as a coat for metal ware to prevent tarnishing and for finishing various products such as playing cards, oil cloth and linoleum and for preserving archeological and zoological specimen. In electrical industry, lac is used as coating of insulator, coating of spark plugs, cement of sockets of electrical lamp, antitracking insulating etc. In Pharmaceutical industry, lac is used in coating of tablets, micro-encapsulation of vitamins and coating of medicines. Lac dye is used in dying of wool and silk, soft drink formulation, pill coating, confectionary and chocolate coating. Lac wax has wide variety of uses in manufacturing shoe polishes, tailors chalk, lipstick, crayons (for writing in glass). Now a days it is also used in fruit coating.
Lac Hosts
The lac insects thrive on the sap of certain plants called lac hosts. So far, over four hundred species of plants have been recorded as hosts of which those are of importance from the commercial stand point are- Palas (Butea monosperma), Kusum (Schleichera oleosa), Ber (Zizyphus mauritiana). Other important lac host plants are Khair (Acacia catechu), Ghont (Zizyphus zylopyra), Barh (Ficus bengalensis), Peepal (Ficus religiosa), Arhar (Cajanus cajan), Galwang (Albizia lucida) etc.
Palas
Kusum
Ber
2.
3.
4. 5.
6. 7.
8.
9.
Arhar (Cajanus cajan) Grewia spp. (G. glabra & G. serruleta) Leea spp. (L. aspera, L. crispa & L. robusta), Ficus cunia Moghania macrophylla Albizzia lucida Kydia calycina Ficus rumphii
10.
10
Sl. No. 1 A. I
Inoculation with Lac Swarming larva . 2 RANGEENI CROPS Katki crop (June July) Baisakhi crop (Oct Nov.)
Crop harvested
4 Oct-Nov
II
Feb-March
April-May Leaving a certain amount of lac on trees to mature and act as brood in July Dec.-Jan June July
June July
B. I. II.
Kusumi crops Aghani crop (June-July) Jethwi crop (Jan.-Feb.) Sept. March - April Jan.-Feb. June July
Lac is not always left on the trees until it matures fully, particularly in case of Baisakhi crop. When it is not mature, it (Baisakhi ari) is cut, leaving a certain amount on the tree to act as brood for the next crop. In Rangeeni, three crops can be obtained from the host tree such as Jalari (Shorea talura) mostly found in Karnataka (Mysore region) and Rain tree (Samanea saman), mostly located in coastal region of West Bengal. These crops are commonly known as Trivoltine crop in which the lac insects pass through three life cycles in thirteen months.
Crop Wise lac Production
Regarding share of different crops, Katki-33.39% (rainy season crop of Rangeeni) contributed the most in national lac production followed respectively by baisakhi27.35% (summer season crop of rangeeni), jethwhi 19.50% (summer season crop of kusmi) and aghani19.42% (winter season crop of kusmi)
LAC ENCRUSTATION
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LAC INSECT
The nymphs emerge in large number at certain times of the year from the lac cells of the female insect depending on the strains and crop seasons, and crawl over the twigs and branches of the plants in search of suitable places for settlement. They settle very gregariously. A healthy female produces 130 to 400 nymphs. The nymphal emergence from a female continues for a fortnight but from a twig comprising of many lac females, it continues for slightly more than 3 weeks and is controlled by the climatic conditions prevailing at that time. The lac nymphs usually emerge in greater number during 8.0 to 12.0 hrs. They thrust their hair like proboscis upto phloem region to derive their nutrition. Once settled, the female never moves during its life time, while the male moves out only during the last phase of its life. The female insect then spends its entire life alone in the lac cell. The larval settlement is very dense at first often completely covering the lower surface of the twigs and sometimes extending to the upper surfaces as well. Density of settlement ranges from 150 to 180 sq. cm. A day or so after settlement, the nymph start secreting resin from the glands, distributed under the cuticle all over the body except near the mouth parts, the breathing pores and the vent. The nymphs thus get encased in cells of their own secretion, which increases in size with the increase in the size of the insect. The male and the female among the young larvae are not easily differentiated by the naked eye. In most cases, the females are preponderant, their population being about three times greater than that of the males. In some progenies the males may be in excess. After secretion of lac, the cell of the
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male is elongated and shaped like a cigar, while that of the female is more or less oval is shape. The lac formed by the male is relatively small and therefore, the occasional preponderance of the males makes a poor crop.
The insect moults three times before reaching maturity, the duration of each instar depending on the host species and the environmental factors. After the first moult, both the female as well as male nymphs lose their legs, antennae and eyes. The male lac cells assume slipper like appearance and a loose operculum at the rear end is clearly seen after the second moult. During the last stage the male insects no longer feed as the mouth parts become atrophied. Subsequently after the second moult, the nymph pass through the prepupal and pupal stage when appendages which ultimately develop into legs, antennae, eyes and wings ( except in apterous males) , aedeagus etc. are seen. The adult males, winged or wingless emerge with the hind end of the body first by pushing the operculum. Normally the winged males occur during the summer crops and the relative number of the two forms in a colony vary considerably in different seasons. A male has life of 62-92 hrs. after emergence and copulate with the female which continues to remain enclosed in the lac cell. A male insect is capable of fertilizing 45 females. The female nymphs unlike the male, do not develop the organs cast off earlier after the first moult except the rudimentary antennae and the organs peculiar to the females become conspicuous. During the subsequent instars the female nymphs become swollen in form and loose all traces of segmentation. They assume form of a pear or roundish bag and completely occupy the space inside the lac cells. After the final and the third moult , the female is sexually mature and is fertilized by the male . Lac secretion by the females continue and the size of the insects as well as that of the enveloping lac cells increase at faster space. The female lac insects thus attain size, which is several times that of a male lac cell, and are therefore, the chief source of lac secretion. The females continue to secrete lac until eggs are laid. As the time of egg laying approaches, the female insects contract at one side, gradually vacating space inside the enveloping lac-cells. The powdery wax and wax filaments are secreted and shed in the vacated space, possibly to provide dry dressing and cushion for the future young nymphs. The anal tubercle is gradually withdrawn inside the cells for laying eggs, which hatch into nymphs immediately after laying. Egg laying ceases if the temperature falls below 17c in summer and 15c in winter. The lac nymphs inside the lac cells become inactive below the temperature of 20c but their capacity to produce lac subsequently under favorable condition is not impaired. The bio-features of females in the progeny are not adversely affected by subjecting the brood lac ( lac encrustation on a twig containing gravid females) to temperature below 20 0c for short period.
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14
15
Pruning Operation
Pruning at proper time is one of the important operations where the branches/ twigs are cut in order to get the maximum numbers of succulent shoots to facilitate feeding of the lac insects. Improvised scientific method of pruning which is done in the brood lac farms is as follows: Pruning is done lightly, because light pruning avoids stunted growth and allows gradual increase in the frame of the tree. Branches more than 2.5 cm in diameter (more than thickness of ones thumb) are not cut. Branches 1.25 cm or less in diameter are cut flush with a branch or trunk from where they arise. Branches between 1.25 cm to 2.5 cm in diameter are cut, so as to leave behind a stalk of about 30-45 cm in length. Dead and diseased branches are removed, split or broken branches are cut below the split. If trees are old and have lost their capacity to produce vigorous shoots of new flush, heavier pruning is carried out to produce the new wood at the expense of the old. Such operation will bring the tree to a better shape, so that subsequent pruning will give the desired flush. Proper pruning should result a good shape and give plenty of room for the development of new shoots.
Objectives of Pruning
To ensure new, good, healthy and succulent shoots. To ensure availability of large number of shoots (larger area for lac insect settlement ). To provide rest to host plant for maintaining it vigour. To remove dead, diseased and broken branches.
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Pruning time
After several years of experimenting at Indian Lac Research Institute ( presently I.I.N.R.G.), Ranchi, Jharkhand, it has been found that the best results are obtained by pruning in February for raising the Katki crop and in April for raising the Baisakhi crop in the case of major Rangeeni host, ber and palas. Pruning in these months will give shoots four and six months old respectively for the lac larvae to feed on. In case of kusum, pruning is best done in the month of June-July and January February. These months coincide with those in which the crops mature and so harvesting of the mature crop serves the purpose of pruning also. Pruning time will, however need to be adjusted to suit local conditions. Under Chhotanagpur (Jharkhand) condition the following pruning times for different lac hosts have been found suitable for lac culture . Kusum (Schleichera oleosa) : Prunning should be done either in January / February or in June / July. Khair (Acacia catechu) Ber (Zizyphus mauritiana) : Pruning is to be done in March. However, harvesting of lac crop during February may be used to serve as pruning also. : Pruning should be done in February for inoculation in July and in April / May for inoculation in October-November. For Kusmi lac crop, ber should be pruned 5 months before inoculation. However, recent observations have shown that harvesting of Aghani crop during February may also serve as pruning for inoculation in June July. Pruning should be done in February for lac inoculation in July and April for inoculation in October November. Pruning is to be done in April for inoculation in July and in May for inoculation in October.
Pruning instruments
Most of the lac cultivators do pruning with axes. Proper pruning can not be done with the axe. If branches are cut with axe, they will either break or split. In both the cases damage to tree will be
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Lac sticks, having mature female insects ready to give rise to the next generation are called brood lac. As the female lac insect is capable of giving rise to a large number of larvae and to get the maximum benefit, it is essential that the brood should be cut at the proper time, so as to secure the emergence of the maximum possible number of larvae from it.
For quality of brood lac, lac crops should be harvested only when mature. The cutting of brood lac should be taken up at the correct time keeping in view the swarming period i.e. the expected date of larval emergence. The ideal time of cutting would be that which will result in the swarming, starting immediately or within a couple of days of tying the brood on the host plant.
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(iii) Bundles of brood lac (about 100 g. by weight) are to be prepared and put these bundles inside 60 mesh nylon netting bags (approx. size 30 x 10 cm.). These will entrap all the predators and parasites but allow the lac larvae to come out. (iv) The brood lac bundles are tied onto the branches parallel to shoots . (v) One meter long brood lac is sufficient to inoculate 10-15 m. long shoots of equal length.
(vi) During the period of inoculation, there are chances of brood bundles falling off and one should go round the inoculated trees in each branch and put such bundles back on the tree. (vii) Attempts should be made to see that the brood lac bundles are not kept on the tree for more that the minimum period required for complete inoculation. Ordinarily, this period will be two to three weeks. If the brood lac is kept even after the lac larvae have completely emerged, there is the danger of a larger number of enemy insects emerging from the empty (phunki) brood lac sticks and infestating the field heavily. Inoculation period in different lac crops Strain Rangeeni Crops Baisakhi Katki Kusmi Ahgani Jethwi Normal inoculation Period Oct. / Nov. June / July June / July Jan. / Feb.
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Harvesting
This operation is done any time after the appearance of yellow spot which appears as a spot about a week prior to emergence of lac larvae. But in case of ari lac (immature) harvesting, the appearance of yellow spot is not considered. Yield of ari lac harvesting is about 25% less than mature crop harvesting. Harvested branches are collected and scrapped to get stick lac. Pruning instruments are used in harvesting. Secateur or long handle tree prunners are better equipments for harvesting lac crop. If there is a surplus brood lac on the host, partial harvesting is done.
Period of harvesting
Type of Harvesting Partial harvesting
Trees Palas
Kusum Palas June / July
Period
Jan. / Feb or June / July Oct. / Nov. (Brood lac coupe tree) April / May (Ari coupe)
Complete harvesting
REMARK : In summer (jethwi and baisakhi crops), complete harvesting is done one week before emergence of the larvae whereas in winter (aghani and katki crops) complete harvesting is done when emergence of larvae start.
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Control
It is difficult to control the squirrels and rats under the open field conditions where lac is cultivated. However scaring away of these animals or poisoning them may be adopted to keep the rodents under attack.
Sl.No.
1.
Family
Encyrtidae
Encyrtidae Encyrtidae Encyrtidae Encyrtidae Aphelinidae
2. 3. 4. 5. 6.
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Family Encyrtidae Eupelmidae Aphelinidae Encyrtidae Aphelinidae Encyrtidae Encyrtidae Encyrtidae Encyrtidae Encyrtidae Eulophidae
Among the parasites listed above Tachardiaephagus tachardiae and Tetrastichus purpureus are the most abundant lac associated parasites. They lay their eggs in the lac cells and the grubs (larvae) hatching out feed on the lac insect within its cell. (II) Predators : The predators on the other hand, are more serious and may cause damage up to 30-35 percent to the cells in a crop. The list of predators of lac insects are given below: Sl. No. 1. 2. 3. 4. 5. 6. 7. Insect Predator Eublemma amabilis E. coccidiphaga E. cretacea E. scitula Pseudohypatopa pulverea Catablemma sumbavensis Cryptoblabes ephestialis Order Lepidoptera ,, ,, ,, ,, ,, ,, Family Noctuidae ,, ,, ,, Blastobasidae ,, ,,
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Insect Predator Phroderces falcatella Lacciferophaga yunnanea Chrysopa madestes C. lacciperda Berginus maindroni Silvanus iyeri Tribolium ferrugineum Phyllodromia humbertiana Ischonoptera fulvastrata
Eublemma amabilis and Pseudohypatopa pulverea are the most destructive key pests of lac insects and are in regular occurrence but their incidence may vary from season to season, place to place and crop to crop.
Life history :
A single female moth lays greyish, flat and rounded eggs singly on the test of lac insect. The newly hatched larvae, 0.51 to 0.54 mm long, get at the lac insect either through the opening of the test or by tunneling a hole through encrustation. A single larva can destroy 40-60 lac insect cells in its whole larval period. It has six generations in a year and the duration of the generations are about 37, 45, 42, 125, 80 and 40 days respectively. Attacked lac cells can easily be identified because of its pinkish colouration due to presence of pink coloured discs of excreta inside the hollow lac cells.
Life history
It lays oval (0.5 mm X 0.3 mm), colourless eggs, singly on the test of lac insects. Larvae pass normally through 5 instars but the hibernating larvae have nine instars. The newly hatched larva is about 1.35
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(iii) Inoculated brood bundles should be kept on the host tree for a minimum period only. (iv) Phunki (empty brood lac sticks) should be removed from the inoculated trees in 2 3 weeks time. (v) All lac cut from the tree and all phunki brood lac (after use as brood lac) not required for brood purpose should be scraped or fumigated at once. (vi) Cultivation of Kusmi strain of lac should be avoided in predominantly rangeeni area and viceversa.
Mechanical control :
Use of 60 mesh synthetic netting (brood bag) to enclose brood lac for inoculation purposes can reduce infestation of enemy insects of lac. The emerging lac larvae easily crawl out from the minute pores of the net and settle on the twigs of the lac host plants, whereas the emerging adult predator enemies can not move out of the brood bags and get entrapped within the net. This can check the egg laying by the predator moths on the new crop.
Chemical control :
Application of 0.05% endosulfan at 30-35 days stage of crop has been identified as the most effective dose of insecticide without any adverse effect on the economic attributes of the lac insect.
Microbial control :
Use of bio- pesticide, Thuricide (Bacillus thuringiensis) at 30-35 days stage of crop is the effective microbial control measure for important enemy insects of lac in field condition.
Biological control :
Two ant predators viz. Camponotus compresus and solenopsis geminate rufa are the most important and promising for biological control of predator enemies of lac in field condition. Egg parasitoids viz. Trichogramma pretiosum, T. chilonis, T. poliae, Trichogrammatoidea bactrae and Telenomus remus have been found to be effective in management of lac predators.
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(iii) Blocking larval emergence (iv) Affecting lac host efficiency. Lac culture during rainy season is prone to fungal attack particularly when grown on Ber (Ziziphus mauritiana), Kusum (Schleichera oleosa) due to their steady and spreading crown. Three species of fungi belonging to family Eurotiaceae and Aspergillaceae viz. Aspergillus awamori, Aspergillus terricola and Penicillium citrinum are reported to cause maximum loss in lac crop. Aspergillus awamori and Penicillium citrinum are black and greenish in colour respectively were observed to make a continuous cover on lac insect culture and thereby blocking their breathing pores and ultimately leading to mortality of lac insects. A pathogenic fungus, Pythium sp. in female tests, causes a heavy mortality on the larvae which fail to enclose satisfactorily and lie dead in clusters within the female resinous cell.
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LITERATURE CONSULTED
Anon. (1972). Indian Forest Utilization. FRI Publ. Govt. of India, Vol. II 941 pp. Anon. (1980). Silviculture of Indian trees. FRI Publ., Govt of India. Vol III Anon. (1999 2000). Annual Lac Bulletin. IFE (ICFRE), Ranchi. Anon. (2001). State of Forest Report, Forest Survey of India, Govt. of India. Anon. (2005). State of Forest Report, Forest Survey of India, Govt. of India. Anon. (2004 2005). Annual Report, Indian Lac Research Institute, Ranchi. Anon.(2007). Lac Statistics at a glance IINRG Publ., Ranchi. Beeson C.F.C..(1941) The ecology and control of forest insect pests of India and the neighbouring countries. Vasant Press, Dehra Dun. 767 pp. Chattopadhyay, S. and Pandey,O.N. (2004). Lac Jungle creation : an approach for forest conservation. In Lac industry-convergence for resurgence, ILRI, Ranchi.3-4. Glover,P.M. (1937). Lac cultivation in India. ILRI, Namkum Ranchi. 119 pp. Krishnaswami, S (1960) Lac cultivation in India. Farm Bulletin, Directorate of Extension, Ministry of Food & Agriculture, Govt. of India, New Delhi, 36 pp.
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