Conceptual notes on bioecology of raily(revised)


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Conceptual notes on bioecology of raily(revised)

  1. 1. BIOECOLOGY OF RAILY – AN ENDEMIC SAL BASED ECORACE OFANTHERAEA MYLITTA DRURY IN BASTAR (CHHATTISGARH)INTRODUCTION:Tropical tasar silkworm Antheraea mylitta D. is an extremely versatile insectspecies and has encountered a wide range of geoclimatic conditions as is evident from itsdistribution. Different ecotypes of A. mylitta isolated geographically over century haveadapted to a particular ecological nature.Chhattisgarh is the second largest producer of tasar silk and bulk of its production,more than 100 MT comes from the nature grown cocoons of the ecorace Raily fromBastar in Chhattisgarh.Raily, an ecorace of wild tasar silkworm Antheraea mylitta D. is endemic toBastar District (Chhattisgarh) which feeds primarily on Shorea robusta (Sal). The Salgrown larvae are robust and the cocoons are compact & tough with rich in silk content.The pupal diapause results in one or two life cycle a year. About five to eight crore Railycocoons are collected by the tribal of Bastar division from different ecopockets. About80% cocoons are collected during Bhadon (July-Aug.) and come to markets during 15thAugust to 30thSeptember, the peak being in 1stfortnight of September. These cocoonsare big in size and superior to that of Chaithi cocoons. About 20% cocoons come to the1
  2. 2. markets during 15thFebruary and 15thApril, peak being March, hence called Chaithicocoons, which are small in size and comparatively in low quality.About 5 to 8 crores Raily cocoons are collected by the tribal of Bastar divisionafter adopting insitu conservation strategies but in recent past the production has declineddue to its over exploitation.Production figures of nature grown Raily cocoons in Bastar during past 24 yearsreveals the growth rate to the tune of 5.64% per annum but the rate of exploitation ismore than the rate of natural multiplication. About 40,000 tribals are engaged incollection of Raily ecorace from forests. (Yadav et al 2010)Continuous collection of nature grown cocoons of ecorace Raily without caringfor the population dynamics and survival, often results in over exploitation of the naturalresources for commercial/economic gains by the mankind, pushing the species to thethreshold limits of extinction. Besides it is one of the minor forest produce on whichthousand of tribals depend on their livelihood. From both these points, there is a need totake measures not only to increase their number in nature but also introduce the ecoracein other areas where the primary food plant sal (Shorea robusta L.) is available inconsiderable density in the forest patches.Conservation strategies are required to be adopted as a long term measures inorder to reduce the loss of valuable natural populations of Antheraea mylitta D. and its2
  3. 3. potential utilities. The interactions of silkworms with external factors determines theirbehavioural activities like relationship between silkworm and its food plants, growth anddevelopments, defensive adaptations, survivability etc. Various ecological factors such asquality of food, temperature, humidity, light, altitudes and geographical locations an important role in determining various activities in tasar silkworms. The essentialecological factors are needed to provide quite conducive and ideal environment for theproper adjustment and acclimatization of tasar silkworm under domesticated conditions.Hence, it is essential to have the thorough knowledge on bioecology andpopulation dynamics in order to stabilize the crop. There is lot of scopes of increasing theproduction of ecorace Raily in Bastar (Chhattisgarh). Attempt will be made to study thebioecology of Raily ecorace in its natural habitat to understand various related aspectswith the changing environmental parameters.REVIEW OF LITERATUREConsiderable preliminary studies have been conducted to know the habitat andhabit of Raily ecorace. Survey conducted in different forest ranges of Bastar divisionrevealed that the maximum availability of Raily cocoons on food plant Shorea robustawith a poor survivality in nature. Quality of the cocoons has been reported to be superiorduring Aug.-Sept. crop than the Feb-March crop. (Annual Report 1988-89). Sevenecopockets of Bastar viz. Darbha, Nangoor, Tokapal, Tongpal, Kondagaon, Narayanpurand Geedam were reported to be identified as the potential areas for the availability of3
  4. 4. Raily cocoons in Bastar. Cocoons of Nangoor ecopocket has been reported to be superiorin economic characters. During survey and collection 36.67% of the cocoons werecollected from Shorea robusta 30.0 % from Terminalia tomentosa and 33.3% fromT.arjuna. The cocoons collected from Shorea robusta were reported to be better thanthese collected from T. arjuna and T. tomentosa (Annual report, 1989-90). Economiccharacters of the cocoons of first crop have been reported to be superior to the cocoons ofsecond crop (Annual report, 1990-91). Morphometric characters of the adult (moth) havealso been studied (Annual Report, 1991-92 to 1993-94). Nangoor, Darbha, Tokapal andTongpal are reported to be highly potential zones which accounted for 70-80% of thetotal natural production (Annual Report, 1991-92, 1992-93 and 1993-94).Studies on preservation of seed cocoons of Raily ecorace conducted from Januaryto June have been reported to result in the minimum pupal mortality in the lots preservedunderground cellar and maximum in outdoor followed by indoor conditions. It is alsoreported that unseasonal emergence is lowest under outdoor in comparison to cellar andindoor condition (Annual Report, 1989-90 to 1994-95). Preservation and behaviouralstudies indicated performance of cocoons processed in insitu is better than thosepreserved in exsitu conditions in terms of effective survival of cocoons, coupling and egglayings (1994-95 to 2000-01).Studies on grainage behaviour of Raily ecorace A.mylitta D. have been conducted(Annual Report 1987-88 to 2000-01). It has been reported that the moth emergence startsfrom the month of March and extends up to July with a peak emergence during the month4
  5. 5. of May (when the temperature was high) during first season. During second season theemergence starts both in indoor and outdoor from the month of October and continueserratically upto February (Annual Report, 1987-88). Emergence percentage of the mothshave been reported to be maximum (84.35%) under indoor conditions during firstpreservation season with a minimum of coupling percentage (3.85%), whereas thecocoons preserved in outdoor hanging on the plant without cover and covered with nylonnet resulted in emergence of 51.09 and 51.7% moths and coupling percentage of 60.33%and 46.53%. Continuous emergence have been reported from March to June periodDuring Second season maximum emergence (64.21%) has been recordedin indoor conditions with a coupling percentage of 20.18%. Under outdoor conditionduring second season emergence have been reported to range between 13.33 - 55.82%with the coupling percentage of 12.22 to 27.50 %. It is further reported that while theemergence under indoor conditions was observed between September and January, thesame was found to range between September and December in outdoor condition.(Annual Report, 1988-89). Better performance in respect of emergence, mating and egglaying in Raily ecorace in Bastar under outdoor condition have been reported incomparison to indoor condition (Annual Report 1989-90 to 2000-01).Optimum periods of brushing for raising of successful silkworm crop ofRaily ecorace has been reported to be 2nd/3rd week of June and first fortnight of Octoberfor Ist and IInd crop respectively in Bastar (Annual Report 1989-90 to 1991-92).5
  6. 6. The rearings conducted on different food plants revealed that thesurvivality of Raily silkworm larvae is more on Terminalia tomentosa followed byT.arjuna and Shorea robusta, however the silk ratio was reported to be higher in thecocoon fed with leaves of Shorea robusta than the Terminalia plants. (Annual Report1989-90 to 1996-97 etc.)To explore the possibility for minimising mortality due to bacteriosis and virosis,the use of Tasar keet Oushadh (TKO) and sodium hypochlorite could not yield anysignificant result in respect of rearing performance of Raily ecorace.(1991-92, 92-93, 93-94). Rearing of Raily silkworm has been reported to have significantly betterperformance under natural conditions than the control.(Annual Report 1996-97 to 2000-01). Preliminary studies on demography of Raily ecorace in Bastar has been done(Annual Report, 2000-01)Significant improvement in the hybrid Raily x Daba over their parents in first crophas been reported in respect of yield as well as survivality (Annual Report 1997-98). TheF1 hybrid has been reported to be stable under different climatic conditions whichconsistently exhibited viability in mating compatibility, hatching, harmonious growth,resistant to diseases, survival, silk yield, short larval period, uniform and reduced flimsycocoons, increase in production and productivity etc. (Annual Report, 2009-10)Out of five methods for observing suitability of natural proliferation of Railyecorace releasing of eggs in Sal leaf cups have been reported to give better performance6
  7. 7. followed by releasing of chawkie worms, releasing of gravid moths, releasing of maleand female moths and releasing of seed cocoons respectively. (Annual Report 1997-98).Raily has been reported to perform better in insitu conditions rather than incaptive conditions indicating that Raily is not amenable for handling because they loosetheir original characters on interference and exhibit low survival (Annual Report 1998-99to 2000-01)Multiplication of Raily through Integrated Package of Rearing has been reportedto marginally enhancing effective rate of rearing in both the crops but the originaleconomic characters of nature grown Raily were not maintained (Annual Report 1998-99to 2000-01).Raily is more or less bivoltine in nature but a part of the population behaves asunivoltine. The first growth season starts from July and ends by September. The secondseason starts from October and continues upto first week of January with overlapping ofgeneration. Later the pupa passes through the diapause stage upto June. Raily isbasically a wild ecorace found in nature and is not amenable for handling as such it isvery essential to know the ecology of Raily ecorace in great detail.Project Period : 3 Years (2012-15)Project Site : Forest of Bastar (Chhattisgarh)7
  8. 8. Budget : Rs. 10.56 lakhsINPUTS• The studies will be carried out under natural conditions at Nangoor forestecopockets of Raily and under exsitu conditions at Sargipal Forest of Field Lab ofRTRS, Jagdalpur.• Under insitu, the observations will be made in nature grown population while underexsitu conditions the observations will be made on population grown due to humanhandling.• Scientists and technical Staff of RTRS, Jagdalpur will be associated withconducting experiments on preservation, grainage and rearing, recording thetechnical and meteorological data.• Estimated budget of the project is Rs. 10.56 lakhs.OBJECTIVES:• To study the biology (Life cycle, grainage and rearing under insitu and exsituconditions etc.) and ecology (host plant interaction, pest and diseases,environmental interaction (rainfall, temperature, relative humidity, photoperiod,wind velocity etc.) in different ecopockets of ecorace Raily.8
  9. 9. METHODOLOGY:I.1. To study on Raily ecorace under natural conditions, the population of this ecoracefrom Nangoor ecopocket will be selected. Forest of RTRS Field Lab Sargipal willbe taken up for studies under exsitu conditions.2. Life cycle, ecology, ethology and population dynamics of Raily ecorace will bestudied in its natural habitat.3. Observations on the seasonal variations in the traits of population viz. eggs, larvae,pupa, moths and cocoons will be recorded.4. Recordings will be made on the abiotic associates viz. Temperature, Relativehumidity, Rainfall and Light etc.5. Abiotic factors will be correlated with the biotic associates and the seasonalvariations in their breeding behavior.6. The recording will be made on the availability of population on different foodplants and during different seasons,7. Most favorable season will be identified based on the population structure.8. Recordings will be made on reproductive potential such as emergence pattern,coupling pattern, fecundity hatching etc. with complete life cycle from incubationperiod of eggs to spinning and further breeding behaviour will be recorded innatural environment.9. Moth morphological traits and quantitative traits of cocoons from all seasons willbe analyzed to draw a normal distribution curve.9
  10. 10. 10. Studies on the effect of biotic factors on the population of ecorace Railya. Food : Status of food plant namely sprouting/flowering/fruiting stage/leafshedding etc. will be recorded in order to correlate with population ofRaily.b. Parasites/Predators/Pathogens: While sampling for collection ofpopulation of Raily in natural habitat, associated parasites/ predators/pathogens will also be collected and their parasitism and predatorstendencies will also be recorded over seasons.II. Similarly, in exsitu conditions, a forest patch of Field Lab Sargipal will be selectedand the Raily cocoons will be infused. All the observations stated above will berecorded so as to standardize rearing schedule of ecorace Raily in different seasons,Treatments :The experiment will be conducted with two locationsxthirteenreplicationsx2seasons = 52 combinations in total. The abiotic associates and bioticassociates germane to Raily will be recorded for each parameters/trait of the study. Thedesign is detailed here below:• Design : RBD• Locations/ Treatments : 02• Replications : 1310
  11. 11. • Season : 02• Total combinations : 52• Error Df : 12• Sample size : 1000 cocoons in each replications• Period (3Years):2013, 2014, 2015• Seasons (Two):March to AugustSeptember-DecemberExperimental DesignLocations/TreatmentL1R1 L1R2 L1R3 L1R4 L1R5 L1R6 L1R7 L1R8 L1R9 L1R10 L1R11 L1R12 L1R13L2R13 L2R12 L2R11 L2R10 L2R9 L2R8 L2R7 L2R6 L2R5 L2R4 L2R3 L2R2 L2R1Observations:• Sprouting behaviour of the food plant will be observed with reference to lifecycle, reproductive behaviour and productivity potential of Raily ecorace.11
  12. 12. • Observations under insitu and exsitu conditions will be made on reproductivepotential such as % of pupal mortality, emergence, coupling, fecundity, hatchingof eggs and productive potential such as Effective rate of rearing/multiplication,cocoon weight, shell weight, Silk ratio and absolute silk production etc.• Incidence of mortality of Raily silkworm due to diseases in relation tometeorological factors will be observed. The harmful effects of different diseaseson the qualitative and quantitative characters will be investigated.12
  13. 13. 4. Activities and duration : The following activities has to be repeated for 3 years from 2013-2015Sl.No.Activity No. andDescriptionActivity Description Period When Locations Who isresponsible1 Survey of Railyecorace fordistribution in BastarSurvey of Raily ecoracefor distribution indifferent forests and onfood plants2.5MonthsJanuary – 1STfortnight ofMarchForest ranges indifferent districts ofBastar division andnewly introducedareas of Chhattisgarh.Scientific andTech. Asst. ofCSB and FieldOff. of DOS, CG2 Procurement of Seedcocoons during 1stcropa)Procurement of seedcocoons of ecorace Railyb) Garlanding/preserva-tion of seed cocoons.15 days15 days15-30 March1-15 AprilInsitu : Machkoteforest rangeExsitu : Sargipal,Jagdalpur-Do-3 Recording of data forinsitu and exsituexperimentsa) Recording of data onpreservation &reproductive potential i.e.survivability, emergence,coupling, hatching, etc,and environmentalparameters.b) Monitoring, recordingavailability of moth, eggsand worms in naturec) Monitoring , recordingmultiplication rate ininsitu and exsituconditionsd) Harvesting of cocoonsunder exsitu and insituconditions, Assessmentof productivity2.5months1 month1.5months15 daysApril-may-1stfortnight of June2ndfortnight June- 1stfortnight ofJulyJuly-Aug (1stfortnight)2ndfortnight ofAugust-Do--Do--Do--Do--Do--Do--Do--Do-13
  14. 14. parameters4 Procurement of Seedcocoons during 2ndcropa) Cocoons harvest of 1stcrop of ecorace Railywill be preserved15 days 1stfortnight ofSept.-Do- -Do-5 Recording of data forinsitu and exsituexperimentsa) Recording of data onpreservation &reproductive potential i.e.survivability, emergence,coupling, hatching etc,and environmentalparameters.b) Monitoring, recordingavailability of moth, eggsand worms in naturec) Monitoring , recordingmultiplication rate ininsitu and exsituconditionsd) Harvesting of cocoonsunder exsitu and insituconditions, Assessmentof productivity1 months1 month3 months15 daysSeptember2ndfortnight ofSept to 1stfortnight of Oct.1stfortnight ofOct. to 2ndfortnight of Dec.2ndfortnight ofDec.-Do--Do--Do--Do--Do--Do--Do--Do-14
  15. 15. Activity table : The following activities has to be repeated for 3 years from 2013-2015Sl Name of the Activity Sub- activities Symbol PrecedingactivityPeriod When1 Survey of Railyecorace fordistribution in BastarSurvey of Raily ecoracefor distribution indifferent forests and foodplantsA 2.5monthsJanuary – 1STfortnight of March2 Procurement of Seedcocoons during 1stcropa)Procurement of seedcocoons of ecorace Railyb) Garlanding/preserva-tion of seed cocoons.BCAB15 days15 days15-30 March1-15 April3 Recording of data forinsitu and exsituexperimentsa) Recording of data onpreservation &reproductive potential i.e.survivability, emergence,coupling, hatching, etc,and environmentalparameters.b) Monitoring, recordingavailability of moth, eggsand worms in naturec) Monitoring , recordingmultiplication rate ininsitu and exsituconditionsd) Harvesting of cocoonsunder exsitu and insituconditions, Assessmentof productivityDEFGCDEF2.5months1 month1.5months15 daysApril-may-1stfortnight of June2ndfortnight June - 1stfortnight of JulyJuly-Aug (1stfortnight)2ndfortnight ofAugust4 Procurement of Seedcocoons during 2nda) Cocoon harvest of 1stcrop of ecorace RailyH G 15 days 1stfortnight of Sept.15
  16. 16. crop will be preserved5 Recording of data forinsitu and exsituexperimentsa) Recording of data onpreservation &reproductive potential i.e.survivability, emergence,coupling, hatching etc,and environmentalparameters.b) Monitoring, recordingavailability of moth, eggsand worms in naturec) Monitoring , recordingmultiplication rate ininsitu and exsituconditionsd) Harvesting of cocoonsunder exsitu and insituconditions, Assessmentof productivityIJKLHIJK1 months1 month3 months15 daysSeptember2ndfortnight of Septto 1stfortnight of Oct.1stfortnight of Oct. to1stfortnight of Dec.2ndfortnight of Dec.16
  17. 17. StartA 10B 2C 2D 10E 4F 6G 2H 2I 4J 4K 12L 2FinishFlow Chart17
  19. 19. OUTPUT1. Biology (Life cycle, reproductive and productivity potential of ecorace Railyunder insitu and exsitu conditions will be evaluated.2. Ecology (host plant interaction, pest and diseases, environmental interaction(rainfall, temperature, relative humidity, photoperiod, wind velocity etc.) indifferent ecopockets of ecorace Raily will be defined.3. Effect of changing environment on biology of ecorace Raily will be established.Beneficiaries and Impacts : Information generated will helpscientific community for planningand executing the multiplication andconservation strategies of naturegrown tasar ecoraces. Increased rate of multiplication tobenefit the cocoon collectors(Tribals) of the area for sustainableuse. Outcome of the project will add toincreasing the production of Railyecorace in Bastar (Chhattisgarh)19
  20. 20. Draft Budget :A. Non-Recurring ( e.g. equipments, accessories etc.)Sl. No. Item 1stYear 2ndYear 3rdYear Total1. Wooden cages 0 0 0 02. Nylon net 35000 0 0 350003. Equipment (Thermometerand Hydrometer)30000 0 0 300004. One Laptop 0 0 05. One Digital Camera 25000 0 0 25000Sub-Total A: 90000 0 0 90000B. Recurring:B1. Manpower:Sl.No.Position Nos. ConsolidatedEmolument1stYear 2ndYear 3rdYear Total1 JRF/SRF/RA 0 0 0 0 0 02 HRA 0 0 0 0 0 03 CCA 0 0 0 0 0 04 Mandays/wages 730 354780 118260 118260 118260 354780Sub-Total B1 730 354780 118260 118260 118260 354780B2. Consumables:Sl. No. Item 1stYear 2ndYear 3rdYear Total1 Seed cocoons 156000 156000 156000 4680003 Miscellaneous( 50000 50000 50000 150000Sub-Total B2 206000 206000 206000 618000Other Items:Sl. Item 1stYear 2ndYear 3rdYear TotalB3 Travel 50000 50000 50000 150000B4 Contingency 0 0 0 0B5 Overhead charges 0 0 0 0Sub-total (B1+B2+B3+B4+B5 etc) 464260 374260 374260 1212780Less Amount to be received from sale of Raily pierced cocoons (-) 156000Total (Rs.) 10,56,78020
  21. 21. From:DR. G.P. MahobiaScientist-CRegional Tasar Research Station, 02-04-2012Kalipur Road, DharampuraJagdalpur (Chhattisgarh)494005Email: mahobiag@yahoo.comTo,The DirectorCTR&TIRanchi –Sir,Sub.:- Follow-up of 34thmeeting of RAC- Submission of Concept note on proposedproject…Reg.Ref.: Letter no. CTR&TI/PMEC/Tech-25/2011-12/11666 dated 30-01-2012With reference to the subject cited above I wish to inform that I had a detailed discussionswith Dr. K. Thangavelu after the Research Advisory Committee meeting held on 8thDecember, 2011 and as per the decision taken under the Agenda item No. 5(5), a conceptualnote on proposed project entitled “Bioecology of Raily – An endemic Sal based ecorace ofAntheraea mylitta D. in Bastar (Chhattisgarh)” has been prepared. I was advised by Dr K.Thangavelu to prepare the project as per the guidelines provided by him and send it first to theDirector CTR&TI, Ranchi for making necessary correction which will be sent to him for finalcorrection.As such the proposed project is enclosed herewith (in hard and soft copies) for taking actionfrom your end.Your’s faithfully’(DR. G.P. MAHOBIA)SCIENTIST-CRTRS, JAGDALPUR21
  22. 22. CONCEPT NOTES ON PROPOSED PROJECTBIOECOLOGY OF RAILY – AN ENDEMIC SAL BASED ECORACE OFANTHERAEA MYLITTA D. IN BASTAR (CHHATTISGARH)Project Proposal Submitted toCENTRAL SILK BOARDMinistry of Textiles (Government of India)BTM Layout, Madivala Bangalore – 560 068ByDr. G.P. MahobiaProject InvestigatorDr. G.S. YadavCo-InvestigatorRegional Tasar Research StationCENTRAL SILK BOARDMinistry of Textiles (Government of India)Jagdalpur (Chhattisgarh) 494 00522
  23. 23. {ks=h; rljvuqla/kku dsUnzREGIONAL TASAR RESEARCH STATIONdsUnzh; jskecksMZCENTRAL SILK BOARDoL= eU=ky;]Hkkjr ljdkjMINISTRY OF TEXT., GOVT. OFINDIAdkyhiqj jksM]/kjeiqjkKALIPUR ROAD, DHARAMPURAtxnyiqj¼NRrhlx<+½JAGDALPUR (CHHATTISGARH)e-mail: rtrsjdpr@yahoo.comnwjHkk"k &07782 229319 Telegram:SILKBOARDdz- ds-r-v-oiz-la-@{ks-r-v-ds-@tx-iqj@ rd-06@2011&12@ fnukad% 02@04@2012lsok esa]funskd]dsUnh; rlj vuqla/kku oizfk{k.k laLFkkuuxM+h & jkWphegksn;~fo"k;%& 34oh vuqla/kku lykgdkj lfefr cSBd& izkstsDVdk dkUlsIV uksV tek djus ckcr AlanHkZ%& Ref: No. CTR&TI/PMEC/Tech-25/2011-12/11666 dated30.01.2012mijksDr fo"k;karxZr lanfHkZr i= ds vuqikyu esafnukWad 8-12-2011 dks gqbZ 34oh vuqla/kku lykgdkj lfefr dh23
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