LIFE CYCLE OF TASAR WORM
- THIRD STAGE OF SILKWORM
- SILKWORMS ON TO MODERN ROTARY MONTAGE
- SILK COCOON IN MOUNTAGES
- SERICULTURE INDUSTRY IN INDIA
- IF FASHION IS A FINE ART, THEN SILK IS ITS BIGGEST CANVAS, AND IF SILK IS THE CANVAS, THEN ALL ITS WEAVERS, DYERS, DESIGNERS, EMBROIDERERS ARE THE GREATEST ARTISTS. INDIAN SILK HAS ENTHRALLED FASHION WATCHERS AND ALL CATEGORIES OF CONSUMERS ACROSS THE WORLD WITH ITS VAST REPERTOIRE OF MOTIFS, TECHNIQUES AND BRILLIANT HUES. INDIA’S TRADITIONAL AND CULTURE BOUND DOMESTIC MARKET AND AN AMAZING DIVERSITY OF SILK GARMENTS THAT REFLECT ‘GEOGRAPHIC SPECIFICITY’ HAS HELPED THE COUNTRY TO ACHIEVE A LEADING POSITION IN SILK INDUSTRY.
- PRESENT STATUS:
- INDIA IS THE SECOND LARGEST PRODUCER OF RAW SILK AFTER CHINA AND THE BIGGEST CONSUMER OF RAW SILK AND SILK FABRICS. AN ANALYSIS OF TRENDS IN INTERNATIONAL SILK PRODUCTION SUGGESTS THAT SERICULTURE HAS BETTER PROSPECTS FOR GROWTH IN THE DEVELOPING COUNTRIES RATHER THAN IN THE ADVANCED COUNTRIES. SILK PRODUCTION IN TEMPERATE COUNTRIES LIKE JAPAN, SOUTH KOREA, USSR ETC., IS DECLINING STEADILY NOT ONLY BECAUSE OF THE HIGH COST OF LABOUR AND HEAVY INDUSTRIALIZATION IN THESE COUNTRIES, BUT ALSO DUE TO CLIMATIC RESTRICTIONS IMPOSED ON MULBERRY LEAF AVAILABILITY THAT ALLOWS ONLY TWO COCOON CROPS PER ANNUM. THUS, INDIA HAS A DISTINCT ADVANTAGE OF PRACTICING SERICULTURE ALL THROUGH THE YEAR, YIELDING A STREAM OF ABOUT 4 – 6 CROPS AS A RESULT OF ITS TROPICAL CLIMATE.
- IN INDIA, SERICULTURE IS NOT ONLY A TRADITION BUT ALSO A LIVING CULTURE. IT IS A FARM-BASED, LABOUR INTENSIVE AND COMMERCIALLY ATTRACTIVE ECONOMIC ACTIVITY FALLING UNDER THE COTTAGE AND SMALL-SCALE SECTOR. IT PARTICULARLY SUITS RURALBASED FARMERS, ENTREPRENEURS AND ARTISANS, AS IT REQUIRES LOW INVESTMENT BUT, WITH POTENTIAL FOR RELATIVELY HIGHER RETURNS. IT PROVIDES INCOME AND EMPLOYMENT TO THE RURAL POOR ESPECIALLY FARMERS WITH SMALL LAND-HOLDINGS AND THE MARGINALIZED AND WEAKER SECTIONS OF THE SOCIETY. SEVERAL SOCIOECONOMIC STUDIES HAVE AFFIRMED THAT THE BENEFIT-COST RATIO IN SERICULTURE IS HIGHEST AMONG COMPARABLE AGRICULTURAL CROPS
- CURRENTLY, THE DOMESTIC DEMAND FOR SILK, CONSIDERING ALL VARIETIES, IS NEARLY 30,000 MTS, OF WHICH ONLY AROUND 23,000 MTS (2012-13) IS GETTING PRODUCED IN THE COUNTRY AND THE REST BEING IMPORTED MAINLY FROM CHINA. INDIAN DOMESTIC SILK MARKET HAS OVER THE YEARS BEEN BASICALLY DRIVEN BY MULTIVOLTINE MULBERRY SILK. DUE TO INFERIOR QUALITY OF THE SILK PRODUCED, INDIA COULD NOT MEET THE INTERNATIONAL QUALITY STANDARD. THOUGH, R&D EFFORTS HAVE BEEN MADE TO IMPROVE THE QUALITY OF MULTIVOLTINE SILK, EVEN THE BEST OF MULTIVOLTINE SILK PRODUCED COULD NOT MATCH THE BIVOLTINE SILK IN QUALITY. THEREFORE, IT IS ESSENTIAL TO ENLARGE THE PRODUCTION BASE AND IMPROVE CURRENT PRODUCTIVITY LEVELS OF BIVOLTINE SILK TO MEET THE INTERNATIONAL STANDARDS AND QUALITY DEMANDS OF THE POWER LOOM SECTOR. STEPS NEED TO BE TAKEN TO ENSURE THAT EXPORT ORIENTED UNITS HAVING AUTOMATIC STATE OF THE ART WEAVING MACHINERY.
- SERICULTURE INDUSTRY IN INDIA
- EXCEPT MULBERRY, OTHER NON-MULBERRY VARIETIES OF SILKS ARE GENERALLY TERMED AS VANYA SILKS. INDIA HAS THE UNIQUE DISTINCTION OF PRODUCING ALL THESE COMMERCIAL VARIETIES OF SILK.
- TRENDS IN INDIAN SERICULTURE:
- OVER THE LAST SIX DECADES INDIAN SILK INDUSTRY HAS REGISTERED AN IMPRESSIVE GROWTH, BOTH HORIZONTALLY AND VERTICALLY. PLANS AND SCHEMES IMPLEMENTED BY CENTRAL AND STATE AGENCIES AND RELENTLESS EFFORTS OF THOUSANDS OF DEDICATED PERSONS IN THE FIELDS OF RESEARCH AND EXTENSION HAVE HELPED IN THIS CONTEXT. FOR INSTANCE, THE AGE OLD MULTIVOLTINE HYBRIDS HAVE BEEN REPLACED BY MULTIVOLTINE × BIVOLTINE AND BIVOLTINE HYBRIDS. THE SERICULTURE INDUSTRY HAS WITNESSED A QUANTUM JUMP IN RAW SILK PRODUCTIVITY. THE AVERAGE YIELD OF 25 KGS OF COCOONS/100 DFLS IN THE RECENT PAST HAS INCREASED AND CURRENTLY THE AVERAGE YIELDS ARE IN THE RANGE OF 60 – 65 KGS/100 DFLS. THE NEW TECHNOLOGY, BESIDES DOUBLING YIELDS HAS ALSO LED TO QUALITATIVE IMPROVEMENTS IN COCOON PRODUCTION WITH CONSIDERABLY REDUCED RENDITTA AND HAS ALSO HELPED BREAK THE CLIMATE BARRIER.
- THE MARKET SHARE OF INDIAN SILK EXPORTS IN THE GLOBAL SILK TRADE IS 4 – 5 % WHICH IS NOT SIGNIFICANT CONSIDERING THE FACT THAT INDIA IS THE SECOND LARGEST PRODUCER OF RAW SILK. THIS IS BECAUSE INDIA HAS A LARGE DOMESTIC MARKET FOR SILK GOODS AND ABOUT 85 % OF SILK GOODS PRODUCED ARE SOLD IN THE DOMESTIC MARKET. HOWEVER, INDIA EXPORTS APPROXIMATELY 15 % OF ITS OUTPUT OF ALL TYPES OF SILK GOODS (INCLUDING VALUE-ADDED ITEMS). THE EXPORT OF INDIAN SILK PRODUCTS CONSISTS OF FINISHED GOODS LIKE FABRICS, MADE-UPS, READY-MADE GARMENTS AND FURNISHING MATERIALS LIKE CURTAINS, CARPETS, BED SPREADS, CUSHION COVERS ETC. THE EXPORT OF SILK PRODUCTS HAS BEEN SHOWING A STEADY GROWTH AND THE EXPORT EARNINGS SHOWED A RAPID INCREASE DURING THE LAST DECADE
- TRENDS IN INDIAN SERICULTURE:
- POTENTIAL, STRENGTHS AND CHALLENGES OF SERICULTURE INDUSTRY IN INDIA
- R&D ACHIEVEMENTS LIKE DEVELOPMENT OF INDIGENOUS MULBERRY VARIETIES WITH HIGHEST LEAF YIELDS IN THE WORLD, NEW BIVOLTINE SILKWORM HYBRIDS EMINENTLY SUITED TO THE TROPICAL REGIONS OF THE COUNTRY, FARMER-FRIENDLY TECHNOLOGIES, COST-EFFECTIVE NEW PACKAGE OF PRACTICES FOR CULTIVATION OF FOOD PLANTS, REARING AND REELING COUPLED WITH HUGE NATURAL AND MAN-MADE RESOURCES AND TRAINED MANPOWER CLEARLY INDICATES THE FUTURE PROSPECTS OF SERICULTURE INDUSTRY TO EMERGE AS A PROMISING INDICATOR OF ECONOMIC DEVELOPMENT FOR THE UPLIFTMENT OF THE SOCIALLY DEPRIVED COMMUNITIES AND THE DOWNTRODDEN. THE STRENGTHS, WEAKNESS, OPPORTUNITIES AND CHALLENGES (SWOT ANALYSIS) OF INDIAN SILK INDUSTRY HAVE BEEN GIVEN
- SERI-BIO-DIVERSITY:
- AMONG 34 MEGA BIODIVERSITY COUNTRIES IN THE WORLD, INDIA IS HOME TO MANY SPECIES OF INSECTS WITH A DIVERSE SILK MOTH FAUNA. IN ADDITION TO THE DIVERSE SILKWORM RACES, THERE ARE VAST GENETIC RESOURCES OF MULBERRY, TASAR, MUGA AND ERI HOST PLANTS SPREAD OVER DIVERSE GEOGRAPHICAL LOCATIONS. THIS OFFERS A GREAT OPPORTUNITY FOR ECONOMIC UTILIZATION OF THE NATURAL FLORA AND FAUNA. HOWEVER, DUE TO DEFORESTATION AND DESTRUCTION OF HABITATS, THERE IS A CHALLENGE TO BRING ABOUT DEVELOPMENT WITHOUT DISTURBING THE ECOLOGICAL BALANCE.
- SERICULTURE AND NATIONAL ECONOMY:
- IN INDIA, SERICULTURE RELATED ACTIVITIES ENSURE THE LIVELIHOOD SECURITY OF OVER SIX MILLION FAMILIES SPREAD OVER IN SOME 59,000 VILLAGES ACROSS THE COUNTRY. THE SILK SECTOR IS ALSO A VALUABLE FOREIGN EXCHANGE EARNER FOR THE COUNTRY. THE EXPORT EARNINGS STOOD AT RS. 2,353 CRORES DURING 2011-12. IN ADDITION, THERE IS AN OPPORTUNITY TO DOUBLE THE EXPORT EARNINGS WITH THE FREE TRADE ATMOSPHERE IN EUROPE AND USA. IT IS ESTIMATED THAT INDIA NEEDS 25,000 MT OF RAW SILK PER YEAR TO MEET ITS DOMESTIC REQUIREMENT. THE GROWING DEMAND OF SILK IN THE DOMESTIC MARKET CAN MAKE THE INDUSTRY A VALUABLE ENTERPRISE WHICH IN TURN CAN PROVIDE EMPLOYMENT FOR THE RURAL MASSES ENSURING ASSURED ECONOMIC RETURNS AT THE INDIVIDUAL FAMILY LEVEL.
- SERICULTURE AND WOMEN EMPOWERMENT:
- WOMEN CONTRIBUTE TO A LITTLE LESS THAN 50 % OF THE COUNTRY’S POPULATION AND MOST OF THEM ARE LARGELY RURAL BASED, DERIVING THEIR LIVELIHOOD THROUGH AGRICULTURE AND OTHER LAND BASED ACTIVITIES, EITHER AS FAMILY MEMBERS OR WAGE EARNERS. AS A COTTAGE INDUSTRY, SERICULTURE PROVIDES AMPLE WOK FOR WOMEN IN THE RURAL AREAS PARTICULARLY IN SILKWORM REARING AND REELING, WHILE MEN, LARGELY WORK IN THE FIELD AND IN WEAVING. THE INVOLVEMENT OF WOMEN IN DIFFERENT ACTIVITIES OF SERICULTURE IS ABOUT 53 % AND THEIR CONTRIBUTION IN THE ON FARM ACTIVITIES UNDERSTANDABLY IS LOWER THAN THAT IN POST-COCOONACTIVITIES . SERICULTURE IS AN IDEAL AVOCATION FOR WOMEN BECAUSE OF THE FOLLOWING FACTS
- BEING RURAL BASED, SERICULTURE NEEDS LESS SPECIALIZED SKILL AND HENCE, SUITS WOMEN WELL.
- INVOLVES MOSTLY INDOOR ACTIVITIES, LESS PHYSICAL ENERGY AND MANUAL LABOUR.
- WORK IS EVENLY SPREAD OVER DURING THE DAY, WITH INTERMITTENT GAPS, OFFERING LEISURE TIME AND PROXIMITY TO LIVING PLACE.
- MINIMUM INVESTMENT WITH LONG LIFE AND SHORT GESTATION PERIOD.
- CONTINUOUS JOB WITH FREQUENT INCOME AND SCOPE FOR UTILIZING SEVERAL BY-PRODUCTS FOR VALUE ADDITION.
- SERICULTURE AND RURAL DEVELOPMENT:
- SERICULTURE BEING A FARM-BASED ENTERPRISE IS HIGHLY SUITED FOR BOTH LARGE AND SMALL LAND HOLDINGS, WITH LOW CAPITAL INVESTMENT. THE VERY NATURE OF THIS INDUSTRY WITH ITS RURAL BASED ON-FARM AND OFF-FARM ACTIVITIES AND ENORMOUS EMPLOYMENT GENERATION POTENTIAL HAS ATTRACTED THE ATTENTION OF MANY PLANNERS AND POLICY MAKERS TO RECOGNIZE THE INDUSTRY AS ONE OF THE MOST APPROPRIATE AVENUES FOR SOCIO-ECONOMIC DEVELOPMENT OF A LARGELY AGRARIAN ECONOMY LIKE OURS. GENERALLY, SILK GOODS ARE PURCHASED BY THE URBAN RICH AND MIDDLE-CLASS CONSUMERS AND IT IS ESTIMATED THAT AROUND 57 % OF THE FINAL VALUE OF SILK FABRICS FLOWS BACK TO THE PRIMARY PRODUCERS IN RURAL AREAS. SERICULTURE CAN ALSO PLAY A VERY VITAL ROLE IN ALLEVIATING RURAL POVERTY DUE TO ITS HIGH WORK PARTICIPATION RATE AND THEREBY CAN CHECK MIGRATION FROM RURAL TO URBAN AREAS.
- SERICULTURE AND EMPLOYMENT GENERATION:
- RAW SILK PRODUCTION IS THE MOST APPROPRIATE TOOL TO PROVIDE GAINFUL EMPLOYMENT TO THESE POORER SECTIONS OF THE SOCIETY, AS NET INCOMES RANGE FROM RS. 12,000 TO 70, 000 PER ANNUM DEPENDING UPON THE VARIETY OF THE SILK TO BE PRODUCED AND THE UNIT AREA (UNDER HOST PLANTS). IT IS ESTIMATED THAT SERICULTURE CAN GENERATE EMPLOYMENT @ 11 MAN-DAYS PER KG OF MULBERRY RAW SILK PRODUCTION (IN ON-FARM AND OFF-FARM ACTIVITIES) THROUGHOUT THE YEAR
- SOURCE:
- CENTRAL SILK BOARD, BANGALORE.
- STEPS TO IMPROVE PRODUCTIVITY AND QUALITY.
- EVOLUTION OF APPROPRIATE COST-EFFECTIVE TECHNOLOGIES THROUGH FOCUSED RESEARCH PROJECTS ADDRESSING CONSTRAINTS AND MAXIMIZING THE PRODUCTION OF QUALITY EGGS.
- TEAMING UP OF SERICULTURE SCIENTISTS WITH MOLECULAR BIOLOGISTS, BIO-ENGINEERS, IMMUNOLOGISTS, TEXTILE TECHNOLOGISTS, CLINICIANS, EXPERTS FROM INDUSTRY AND A HOST OF OTHER STAKEHOLDERS IN CHARTING OUT A NEW ROAD MAP.
- ADOPTION OF REGION AND SEASON SPECIFIC APPROACHES IN THE DEVELOPMENT OF SUPERIOR BREEDS / HYBRIDS AND FEED PACKAGE OF PRACTICES.
- ESTABLISHMENT OF CLOSE LINKAGE BETWEEN FORWARD AND BACKWARD SUB-SYSTEMS FOR GREATER EFFICIENCY AND SYNERGY AS SERICULTURE AND SILK INDUSTRY IS HIGHLY SCATTERED AND UNORGANIZED.
- IDENTIFICATION AND PROMOTION OF POTENTIAL CLUSTERS FOR BIVOLTINE AND VANYA SILK PRODUCTION IN POTENTIAL TRADITIONAL AND NON-TRADITIONAL AREAS.
- SKILL UP-GRADATION THROUGH STRUCTURED AND SPECIALLY DESIGNED TRAINING PROGRAMS.
- ESTABLISHMENT OF LINKAGES AMONG THE FOUR IDENTIFIED PRODUCTION SUB-SYSTEMS VIZ., SEED, COCOON, YARN AND FABRIC.
- CAPACITY BUILDING FOR PRODUCTION AND SUPPLY OF ADEQUATE QUALITY PLANTING MATERIAL, SILKWORM SEED, REELING COCOONS AND SILK YARN THROUGH PROMOTION OF LARGESCALE PRODUCTION UNITS WITH REQUIRED TECHNO-FINANCIAL SUPPORT.
- DEVELOPMENT AND PROMOTION OF PARTICIPATORY EXTENSION SYSTEM FOR EFFECTIVE ADOPTION OF TECHNOLOGIES BY SIMILAR STAKEHOLDERS.
- PROTECTION TO SOME EXTENT OF INDIAN SILK MARKET FROM CHINESE CHEAP RAW SILK AND FABRICS BY IMPLEMENTATION OF ANTI-DUMPING DUTY.
- EFFECTIVE UTILIZATION OF BY-PRODUCTS FOR VALUE ADDITION.
TASAR CULTIVATION IN FOREST AREAS
- Tasar areas are primarily classified as follows
- Traditional –
- Areas where tasar cultivation has been done by the local population specially Tribals for a very long time. For example tasar cultivation is a regular feature of tribal population in Jharkhand, Chhattisgarh, Odisha . Similarly Karnataka, Andhra Pradesh, Tamil Nadu, West Bengal and Jammu Kashmir are traditional Mulberry states.
- Non- traditional-
- Areas where there is sufficient food plants to introduce such as Madhya Pradesh, Uttar Pradesh etc but have not been doing Tasar cultivation historically.
- The traditional tasar areas have an advantage that they already have technologies well established with the local population and the government has to play only a proactive role. In case of non-traditional states selection of forest areas , identification of beneficiaries, training and motivation has to be done from the start.
- Traditional –
- Following steps are involved in Tasar cultivation
- Process in Nutshell-
- The beneficiaries are given a certain quantity of eggs which they nurture (rear) in selected forest areas. After the silkworms form a cocoon the
cocoons are collected and bought by the department or an outside agency. The whole cycle takes about 40 to 45 days. The process stars immediately with the onset of monsoon as the humidity builds .During the period the beneficiaries protect the larvae from parasites such as birds, monkeys, snakes and diseases. The second crop starts immediately after the fist crop is over as there is enough humidity left .Process in detail is as follows. In various parts of the country the process is adopted by joint forest management committiees.
- The beneficiaries are given a certain quantity of eggs which they nurture (rear) in selected forest areas. After the silkworms form a cocoon the
- Selection of forest areas. –
- Forest areas where a certain minimum of 500- 1000 tasar food tree like saja and arjun should be selected. Care should be taken that there is enough tree leaves in the crop. In order to manage larvae transfer large tree should be avoided.
- Selection of Beneficiary-
- beneficiaries should be selected from local villages who know the topography and the forest. They should be willing to invest their whole time for 45 days in the forests. Every beneficiary is given 200DFLs for rearing. A normal dense forest with about 3000-4000 trees per hectare is sufficient for 200DFLs. But in case of acres of scares patches the area allotted to a beneficiary for 200DFls should be increased by equivalent proportion.
- . Training-
- The beneficiaries have to be trained as Tasar rearing is an specialized process. normally the beneficiaries are trained in the first crop.
- Preparing the site. –
- Then forest area which is selected has to be cleaned for bushes and weeds so that insects and other fauna are minimized. The ground has to be disinfected for disease and the leaves are also disinfected for disease like gall .
- Inoculation of eggs. –
- Every beneficiary is given 200 DFL,s. A DFL is a defined as Disease Free Laying that is a group of eggs laid out by a moth which has been certified as disease free. Normally it consists of 200 healthy eggs. These eggs are initially put over a small shrub of tasar food tree and are covered by net for protection from predators. After a week of hatching they are transferred and spread to other tasar food trees. The process of initial hatching and rearing of tasar eggs is called Chawkie rearing.
- Food Plant Management.-
- The larvae are transferred from tree to tree as they continue to feed. A typical larva eats up to 30 times of its final weight.
- Spinning-
- After about 30 to 35 days the larvae starts to make cocoon. This process is called spinning. it takes about 2 to 3 days. It then settles inside the cocoon as a pupa. The cocoons are collected and are ready for either reeling or for next crop.
- Grainage .-
- Since there is enough humidity in the atmosphere the pupa after days comes out as moth and the cycle is repeated. By the end of the second crop the winter season begins hence there is not enough humidity and temperature for next cycle to begin. Hence in this case the pupa inside goes for diapauses till next monsoon. Good quality cocoons depending upon next year requirement are stored as seed cocoons rest are used for reeling to be converted into thread and raw silk.
- Seed Crop and commercial crop-
- The first crop with the onset of monsoon is called Seed Crop as it provides eggs for the next crop. The quality of the cocoon is poor and has lot of moisture. The second crop is called Commercial Crop as the quality is good.
- Process in Nutshell-
- GRAIANGE
- The process of Tasar egg making in lay mans term is called grainage. It involves storage of eggs, facilitating of male female coupling, washing cleaning of eggs and disease checking. After the first crop the pupa inside the cocoon goes into diapauses that is hibernation till next cycle. Good quality of cocoon are selected and stored in the grainage houses where temperature and humidity are maintained and controlled.
- with the onset of monsoon the moths start coming out of cocoon. The moth immediately start coupling with opposite sex and within 3 days of coupling start laying eggs. These eggs are collected washed with soap and other chemicals and are examined under a microscope for diseases primarily for Pebrine which is a
- protozoan disease capable of destroying whole crop. Once the samples are certified as disease free they are labeled as DFL and are sent to the fields where they are supposed to be reared. Each DFL has a fixed date for hatching hence each DFL group is labeled properly with the date of hatching so that they reach the site and inoculated before hatching.
ECONOMICS OF TATSAR CULTIVATION
- A beneficiary is given one hectare of forest land or an equivalent area for 200DFLs. An equivalent area for Tasar cultivation is about 5000 tasar trees per hectare. If suppose there are 2500 trees per hectare then 100 Dfls will be used and it will be half hectare in equivalency.
- Each DFL contains 200 healthy disease free eggs.
- Each egg has the potential to become full grown cocoon. Therefore theoretically a group of 200 DFLs can gives 40,000 cocoons.
- But actually there are hatching losses about 10% and depending upon the care taken by beneficiary losses due to predators and weather losses.
- Normally in traditional areas the out put is about 50 cocoons per 200DFLs.
- Normally the price of a cocoon varies from lowest grade 30 paisa to 2 Rupees. Therefore the average cost of the produce is about 1 Rupee.
- Therefore a beneficiary in one crop gets about Rs 10000 in 45 days.
- The yield in the second crop is higher and the beneficiary may earn up to 15- 25000 in second crop.
- Therefore a beneficiary in two crops may earn between 25,000 to 50,000.
- In traditional areas some beneficiaries earn up to between 1 to 2 lacks working in family groups.
- Due to the presence of the beneficiaries the forests are protected as the income of the beneficiaries depend upon the abundance of food plants.
- The production of cocoons in the forest areas leads to development of other decentralized cottage industries like reeling, dyeing and weaving.
TECHNICAL TERMS ASSOCIATED WITH SILK CULTIVATION
- Voltism-
- It refers to number of life cycles per year. Depending upon ecorace a typical silkworm may have one (Uni), two(Bi), three (Tri) or Multi(more than three) life cycles.
- DFL-
- Disease free laying. . A DFL is a defined as Disease Free Laying that is a group of eggs laid out by a moth which has been certified as disease free. Normally it consists of 200 healthy eggs. After emergence from the cocoon male moths immediately couple with female moths. After a period of 24-36 hours female moth lays eggs in about three batches. These eggs are cleaned washed and examined under the microscope for diseases specially pebrine. After a batch ic certified as disease free then only it is used for rearing in the field.
- Chawkie rearing.
- Initially laid eggs when transferred in the field are hatched under supervision in few selected shrubs for a week. This natal stage rearing is called Chawkie rearing. After a week the one week old larvae are spread all over the forest areas.
- Pebrine.-
- Pébrine is a disease of silkworms, which is caused by microsporidian parasites, mainly Nosema bombycis and to a lesser extent Variomorpha, Pleistophora and Thelophania species. The silkworm larvae infected by pébrine are usually covered in brown dots and are unable to spin silkworm thread. Louis Pasteur was the first one to recognize the cause of this disease when a plague of the disease spread across France. It is the most dangerous silkworm disease and often leads to epidemic form there by destroying crops not only at local level but at state and even national level. Precaution includes disinfection and burning of the ground soil surface.
- Diapause-
- After the cocoon has been spun and the pupa sets inside the cocoon it goes into hibernation or diapauses. In case of Tasar during the first crop at the onset of monsoon the pupa goes into diapause for one week. Since there is still sufficient humidity it emerges as a moth and the lifecycle is repeated. After the second crop winter sets in and there is not sufficient humidity. Therefore the pupa remains in the cocoon in the diapauses state for about six months till the next onset of monsoon.
- Grainage-
- The process of Tasar egg making in lay mans term is called grainage. It involves storage of eggs, facilitating of male female coupling, washing cleaning of eggs and disease checking.
- Molt .
- A silkworm goes into molt phase five times in its life cycle of 30-35 days. During this process it sheds its skin and does not eat. This is because there is enormous enlargement in its size. During this process the old skin is shed and new skin comes up.
- Ecorace-
- Due to agro climatic variations in the country various silkworm have adopted to local conditions and have evolved into distinct ecoraces. For example daba, modal, rally, laria are ecoraces of Tasar. Similarly in case of Mulberry ecoraces are developed by Central Silk Board to get maximum, productivity for a particular area.