Journal of Environment and Sociobiology

Himanish Bhattacharyya ¹, Kunal Sarkar ², Biplab Kumar Modak ³

Affiliations
1 Department of Agriculture and Rural Development, Chandraketugarh Sahidullah Smriti Mahavidyalaya, Berachampa, North 24 Parganas, West Bengal, IN
2 P. G. Department of Sericulture, Krisnath College, Berhampore, Murshidabad, West Bengal, IN
3 Department of Zoology, Sidho Kanho Birsha University, Purulia, West Bengal, IN

Abstract

Silkworm eggs play crucial role in sericulture industry. For successful production of cocoon crops adequate quantity of good quality egg is essential. In case of silk moth mating time varies from 1 - 4 h which is generally termed as coupling period. The temporal aspects of mating in terms of duration may also have impact on the number of egg laid, pattern of egg laying and their viability. The present investigation intends to find out whether duration of coupling period has any relation with fecundity and fertility of silk moth. The study was conducted with the cross breed of following Bombyx mori breeds: NxM12(w), NxNB4D2, and NxYB. The experiment reveals that total fecundity almost remained same with the variation of coupling duration but fertility is directly proportional to coupling duration and maximum (100%) at 5 h coupling duration.

Keywords

Fertility, Fecundity, Coupling, Egg.

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Susanta Kumar Chattopadhyay ¹, Kunal Sarkar ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad 742101, West Bengal, IN

Abstract

Sericulture is an agro-based labour intensive cottage industry. This industry has multi-dimensional aspects including cultivation and maintenance of host plants, rearing of silkworm larvae, reeling of silk extruded by the matured larvae, weaving and printing of woven silk. Silk was originated in China in around 3000 B.C. India is the only country of the world which produces all four types of silk, viz., Tasar, Eri, Muga and Mulberry silk and is the second largest silk producing country of the world next to China. At present almost 6 million people are engaged in different activities of this industry. This industry can provide remunerative employment of 13 persons/hectare/year. Major mulberry silk producing states of India are Karnataka (7301 MT), Andhra Pradesh (5084 MT), West Bengal (1520 MT), Tamil Nadu (443 MT), Jammu and Kashmir (90 MT) and others (181 MT). West Bengal is one of the major traditional states of mulberry silk production in India. Malda, Murshidabad and Birbhum are the major tradional districts of Sericulture in West Bengal.

Keywords

Sericulture, Silk, India, West Bengal.

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Kunal Sarkar ¹, Dilip Kumar Bhattacharya ², Susanta Kumar Chattopadhyay ¹, Subrata Trivedi ¹, Sudeshna Ghoshal ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad-742101, West Bengal, IN
2 Department of Zoology, University of Kalyani, West Bengal, IN

Abstract

The Study Evaluated the Effect of Feeding of Different Maturity Level of Mulberry Leaves, I.e., Tender, Medium, Mix and Mature Leaves on the Commercial Characteristics of Crossbreed (N×NB₄D₂) during Dry Summer in West Bengal. the Data Obtained during the Study was Compared with those of Control where Conventional Leaf Feeding Method was Followed. most of the Larval and Cocoon Characters, Viz., Larval Weight, Effective Rate of Rearing, Cocoon Weight, Shell Weight and Shell Ratio Percentage, Etc., were Recorded Significantly Higher in Tender Leaves Fed Batches Followed by Medium Leaves Fed Batches. Significantly Higher Post Cocoon Parameters, Viz., Average Filament Length, Nonbreakable Filament Length, Renditta and Raw Silk Recovery Percentage, Etc., were Recorded in Tender Leaf Fed Batches. Qualitative Analysis of Leaves also Suggested that Tender Leaves are more Nutritious than other Maturity Level of Leaves. Mature Leaves Fed Batch Showed Inferior Performance in Terms of all the Characters. the Present Experiment also Revealed that 20% of Tender Leaves can be Saved Particularly in Dry Summer, which are Generally Clipped by Sericultural Farmers in West Bengal in Late Larval Instar before Providing Mulberry Shoots to Silkworm Larvae.

Keywords

Mulberry Leaves, Maturity Level, Cocoon Characters, Reeling Characters.

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Kunal Sarkar ¹, Dilip Kumar Bhattacharya ², Susanta Kumar Chattopadhyay ¹, Subrata Trivedi ¹, Sudeshna Ghoshal ¹, Vinod B. Mathur ³

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad-742101, West Bengal, IN
2 Department of Zoology, University of Kalyani, West Bengal, IN
3 Central Sericultural Research and Training Institute, Mysore, Karnataka, IN

Abstract

Present investigation indicates that feeding larvae with Mulberry leaves which were water dipped and dried for entire larval instar (T2) and in late larval instar (T4) gave better performance than control in respect of most of the larval and cocoon characters. But feeding larvae with leaves immediately water dipped for entire larval instar (T₁) and in late larval instar (T3) showed inferior results in terms of all commercial characters in wet summer. This investigation suggests that leaves with high moisture content are not harmful for silkworm larvae at any season but water in the surface of leaves may be harmful for them. So it is important to feed silkworm larvae by just shaking the water from surface of the leaves or by drying the leaves for few minutes particularly during rainy season when the leaves are wetted due to rain. Investigation also reveals that if the wet leaves are dried for some time, it helps to increase the moisture percentage of leaves. Then it is also helpful to improve the cocoon characters.

Keywords

Water Treated Mulberry Leaves, Cocoon Characters, Reeling Characters.

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Subrata Trivedi ¹, Kunal Sarkar ¹, Susanta Kumar Chattopadhyay ¹, Gopinath Baur ¹, Manmatha Mandal ¹, Somdip Majumdar ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad-742101, West Bengal, IN

Abstract

Of all factors that govern productivity in sericulture, the role of silkworm egg is of prime importance. It is the sheet anchor of sericulture industry. Timely supply of appropriate quality and adequate quantity of disease free silkworm eggs to the sericulturists is crucial for successful harvest of cocoon crops. Silk moths have a tendency to pair immediately after emergence from cocoons. The present study indicates that in case of N×M₁₂W, N×NB₄D₂ and N×YB crossbreeds at least 95%-99% fertilized eggs can be procured by using a single male moth for 4 times in crossing. So, if male moths are used 4 times during multiple crossing it would not affect the fertility of eggs. The present investigation also reveals that total fecundity almost remained same with control when male moths were even used for seven times in crossing. This suggests that that a single male moth can be used for four times by giving them sufficient rest in crossing with female moth and in this way a grainure can save considerable cost and hazards during the purchasing of seed cocoons of male components.

Keywords

Bombyx mori, Multiple Crossing, Silkworm Eggs, Fecundity, Fertilized and Unfertilized Eggs.

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Kunal Sarkar ¹, Dilip Kumar Bhattacharya ², Susanta Kumar Chattopadhyay ¹, Subrata Trivedi ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad-742101, West Bengal, IN
2 Department of Zoology, University of Kalyani, West Bengal, IN

Abstract

In West Bengal rearing season of Mulberry is divided mainly in two parts, i.e., favourable season (November to April) and unfavourable season (May to October). Mulberry crop span is 70 days. So five harvests as well as five rearings can be done in a year. November crop (winter or Agrahani), February crop (spring or Falguni) and April crop (summer or Baishakhi) come under favourable season (dry summer) whereas June-July crop (rainy or Shrabani) and August-September crop (autumn or Aswina) come under unfavourable season (wet summer). A study was conducted from November, 2003 to November 2006 to evaluate the performance of multivoltine hybrid Nistari × M₁₂ (W) and cross breed Nistari × NB₄D₂ of Bombyx mori during favourable and unfavourable seasons. The study revealed that during favourable season performance of cross breed Nistari × NB₄D₂ is better but during unfavourable season Effective Rate of Rearing is very less and melting percentage is considerably higher in case of Nistari × NB₄D₂ batch as compared to Nistari × M₁₂ (W) batch.

Keywords

Nistari × NB₄D₂, Nistari × M₁₂ (W), Rearing Season.

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Kunal Sarkar ¹, Subrata Trivedi ¹, Dilip Kumar Bhattacharya ², Susanta Kumar Chattopadhyay ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad-742101, West Bengal, IN
2 Department of Zoology, University of Kalyani, West Bengal, IN

Abstract

In India sericulture is mainly confined to its tropical belt. This country has a number of polyvoltine races which are in use for a long time and considered indigenous. Though these indigenous races are poor silk yielder but still these are very popular due to their tremendous ability to survive under extreme tropical conditions. Besides that, some bivoltine breeds are also evolved throughout the country due to some sincere efforts of our silkworm breeders. Here an effort is made to study the major silk worm races of our country.

Keywords

Silkworm Races, Multivoltine Race, Bivoltine Race.

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Subrata Trivedi ¹, Kunal Sarkar ², Dilip Kumar Bhattacharya ², Susanta Kumar Chattopadhyay ², Sudeshna Ghoshal ²

Affiliations
1 Department of Zoology, University of Kalyani, West Bengal, IN
2 Department of Sericulture, Krishnath College, Berhampore, Murshidabad-742101, West Bengal, IN

Abstract

The present study was conducted on number, length and the pattern of pubescence in different maturity level of leaves in different improved mulberry varieties i.e., S₁, S₁₆₃₅ and also in a local variety which are commonly cultivated in various parts of West Bengal. The study reveals that density of pubescence is more in tender leaves, but the pubescence in tender leaves is immature in stage. Tip of pubescence is blunt in case of tender leaves. Length of pubescence is increased and tip of pubescence is sharp and pointed in case of mature leaf. Length of pubescence is less in S₁₆₃₅ variety in all types of leaves as compared to that the local and S₁ varieties. But in case of local variety pubescence is longest. Tip of pubescence is found more sharp in case of local variety and less sharp in case of S₁₆₃₅ variety. This result indicates that among these three varieties insects prefer to feed S₁₆₃₅ variety in terms of pubescence study. On the other hand, due to presence of immature and blunt type of pubescence, tender leaves are more favourable and palatable for silkworm larvae.

Keywords

Pubescence, Maturity Level of Leaves, Mulberry Varieties.

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Kunal Sarkar ¹, S. K. Chattopadhyay ¹, G. Baur ¹, Subrata Trivedi ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad-742101, West Bengal, IN

Abstract

Sericulture is an age old industry in West Bengal. At present mulberry is cultivated in 33560 acres of land and 107000 families are engaged in mulberry sericulture. Estimated mulberry raw silk production during 2004-2005 was 1520 MT (10.39% of total mulberry raw silk production in India). But still a heavy decline in sericulture is seen in West Bengal. In 1997-1998 mulberry was cultivated in 53,395 acres (21358 ha) of land but it is now reduced to merely 33560 acres of land. There are several factors behind that downfall of sericulture in this state. Lack of adoption of improved sericultural practices may one of them. Hence, in the above context it is worthwhile to conduct research studies in two major traditional districts of West Bengal i.e., Malda and Murshidabad. The present study was conducted in the Nabagram Block of Murshidabad district and Kaliachawk Block-2 of Malda district to assess farmers' knowledge and their adoption level in respect of recommended sericulture practices so that field extension workers could develop appropriate educational approaches to upgrade their adoption level for increasing the cocoon yields, thus aiding in generation of higher income and employment among the rural mass. The findings of the present study indicated that only 50% of big farmers and 25% of small farmers had planted improved variety of Mulberry and followed recommended spacing and recommended system of planting. The present study also reveals that farmers have very low level of knowledge with respect to work spacing, number of feeds, types of leaves to be fed to different instars, leaves preservation methods, number of bed cleanings, temperature manipulation measures and prevention measures for various silkworm diseases. In general, irrespective of the category, sericultural farmers are not applying recommended dosage of fertilizers to mulberry crop.

Keywords

Sericulture, Traditional District, Recommended Practices.

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Kunal Sarkar ¹, S. K. Chattopadhyay ¹, Subrata Trivedi ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore Murshidabad-742101, West Bengal, IN

Abstract

West Bengal experiences severe hot, humid summer and rainy season with higher precipitation rate, which makes the management of silkworm rearing very difficult. As a result, farmers of West Bengal fetch poor return owing to low productivity of cocoons. In this context it is important to manage silkworm rearing properly. In order to manage a profitable silkworm rearing it is indispensable to make proper planning prior to the initiation of silkworm rearing, management during the rearing of young age silkworms, late age silkworms and mounting and harvesting cocoons.

Keywords

Silkworm Rearing, Young Age Rearing, Late Age Rearing, Mounting, Harvesting.

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Sagnik Kumar Ganguly ¹, Arindam Chakraborty ², Gopinath Baur ³, Sanat Roy ³, Subrata Trivedi ³, Kunal Sarkar ³

Affiliations
1 1 Debitala lane, Ichapur, 24-Parganas (N), West Bengal 743144, IN
2 Department of Serculture, Krishnath College, Berhampore, West Bengal, IN
3 Post Graduate Department of Serculture, Krishnath College, Berhampore, West Bengal, IN

Abstract

Total Hemocyte Count in spinning silkworm, Bombyx mori L. was studied using four popular multivoltine races of India. Hemocytic concentration of larva was gradually decreased in every spinning day then again increased with pupal maturity. It was a common character for all the four races in the larva to pupa transition stage. Spherulocyte abundance and prohemocyte absence are other general features in the pre-pupal stage in these four races. It is shown that spherulocytes are derived from granulocytes.

Keywords

Hemocyte, Pre-Pupal Stage, Bombyx mori.

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Kunal Sarkar ¹, Susanta Kumar Chattopadhyay ¹, Gopinath Baur ¹, Sanat Kumar Ray ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad, West Bengal 742101, IN

Abstract

The effect of earlier and delayed mounting of matured larvae on the commercial characteristics of Bombyx mori L. was investigated in the present experiment. There are no significant differences in yield, cocoon and reeling characters between the control (larvae mounted after ideal maturation) and larvae mounted 24 hours after maturation. The present study indicates that larvae mounted 24 hours before maturation give significantly inferior results in terms of yield, cocoon and reeling characters as compared to other characters. The study also indicates that late mounting of larva does not affect quality of cocoon but early mounting of larvae may seriously affect the quality of cocoon. The main reason behind this is that early mounting of silkworm larvae does not allow to create superfluous amino acids in the body and hence it does not excrete from the body. It ultimately affects the process of cocooning. Hence hurry in mounting is not desirable before ideal maturation of larvae, even if labour or time is not available. Rather farmers may wait for a day after ideal time of maturation.

Keywords

Bombyx mori, Maturation, Mounting, Cocoon.

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Kunal Sarkar ¹, Susanta Kumar Chattopadhyay ¹, Gopinath Baur ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad, West Bengal 742101, IN

Abstract

The effect of feeding frequency on the commercial characteristics of Bombyx mori L. was investigated in the present experiment. The result indicates that there is no significant differences between frequency of feed 4/day (control) (T⁰) and frequency of feed 3/day (T¹) in dry summer. But frequency of feed 2/day (T²) is not effective in dry summer. During dry summer 4 feeds/day is ideal to maintain requisite humidity in the rearing bed. The present study clearly indicates that double feeding is highly useful in wet summer. Double feeding is highly economic in terms of management of labour, rearing and other rearing operations.

Keywords

Bombyx mori, Feeding Frequency, Double Feeding, Silkworm.

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Kunal Sarkar ¹, Susanta Kumar Chattopadhyay ¹, Gopinath Baur ¹, Sanat Kumar Ray ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad, West Bengal 742101, IN

Abstract

The effect of using banana leaves and aurum leaves as seat and cover of rearing tray on the commercial characteristics of Bombyx mori L during dry summer was investigated in the present experiment. In dry summer using of banana leaves and aurum leaves as seat and cover in the rearing tray gave better result than conventional method of using paraffin paper for the same purpose. Using of these leaves as seat and cover of rearing tray increased the moisture retention capacity of mulberry leaves which ultimately ensured the better economic characters of silkworm larvae as well as cocoons. Not only in early stages but also in late stages, silkworm larvae may be reared by using banana leaf and aurum leaf as seat and cover. Besides these cost of banana leaf and aurum leaf is negligible and these are easily available at farmers level.

Keywords

Bombyx mori, Rearing Tray, Banana Leaf, Aurum Leaf, Paraffin Paper.

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Kunal Sarkar ¹, Susanta Kumar Chattopadhyay ¹, Gopinath Baur ¹

Affiliations
1 Department of Sericulture, Krishnath College, Berhampore, Murshidabad, West Bengal 742101, IN

Abstract

The effect of feeding duration on fifth instar silkworm larvae on the commercial characteristics of Bombyx mori L. was investigated in the present experiment. The present study clearly indicates that larval duration in 5^th instar directly correlates with the commercial characters of cocoons. Maximum larval duration as well as maximum leaf feeding ensures maximum harvest. Silkworm larvae fed with mulberry leaves upto 3^rd day in 5^th instar resulted no cocoons in the mountages. Even after complete maturation of silkworm larvae, it is desirable to feed silkworm larvae even for an extra day; otherwise cocoon quality would be seriously affected.

Keywords

Bombyx mori, Feeding Duration, Fifth Instar, Silkworm Larvae.

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Kunal Sarkar ¹, Gopinath Baur ¹, Somdip Majumdar ¹

Affiliations
1 Post Graduate Department of Sericulture, K. N. College, Berhampore, Murshidabad-742101, West Bengal, IN

Abstract

Mulberry plants are seriously damaged by various types of sap sucking insect pests in West Bengal. Most remarkable sapsuckers are mealy bug, white fly and thrips. Mealy bug sucks nutrient rich plant sap from tender top and injects toxic saliva to it causing serious morpho-physiological abnormality called 'Tukra'. White fly is a major sap sucking minute polyphagous pest which seriously damages the crop by sucking the plant sap from leaves and young shoots and secretes honey dew to welcome other sooty moulds. Thrips, both nymphs and adults, tear the epidermal leaf tissues with their stylets and suck the plant sap causing low nutritive value of leaves.

Keywords

Insect Pests, Tukra, Whitefly, Thrips.

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Himanish Bhattacharyya ¹, Mahasankar Majumder ², Kunal Sarkar ², Biplob Kumar Modak ³

Affiliations
1 Department of Agriculture & Rural Development, Chandraketugarh Sahidullah Smriti Mahavidyalaya, Berachampa, 24PGS(N), IN
2 Post graduate Department of Sericulture, K. N. College, Berhampore, West Bengal, IN
3 Department of Zoology, Sidho-Kanho-Birsha University, Purulia, West Bengal, IN

Abstract

Common diseases of silkworms in West Bengal are White Muscardine (fungal), Grasserie (viral), Flacherie (viral and bacterial complex) and Pebrine (Protozoa). Present study intends to study the prevalence of various silkworm diseases of Baishakhi crop at Murshidabad district, West Bengal. The study finds that Flacherie is more predominant (18%), followed by Grasserie (10.5%) in both lab and land conditions in Baishakhi or April crop than any other diseases at Murshidabad district. However, occurrence of Muscardine and Pebrine diseases in Baisakhi crop of the district is not recorded during the study period.

Keywords

Mulberry Silk, Silkworm Disease, Baishakhi Crop, Murshidabad.

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Mahasankar Majumdar ¹, Kunal Sarkar ¹, Sanat Kumar Ray ¹

Affiliations
1 PG Department of Sericulture, Krishnath College, Berhampore, Murshidabad,West Bengal, IN

Abstract

Sericulture is recognized as an important agro based labour intensive cottage industry in India. In this study, we have made a comparative analysis on the income generation from sericulture as compared to traditional horticulture crops, i.e., Mango (Mangifera indica) and Litchi (Litchi chinensis). Our study clearly indicates that sericulture is capable of generating more income than other horticulture crops like Mango, Litchi, etc. Mango and Litchi fruits can be produced normally once in a year but sericulture can be practiced 4-5 times in a year. The net income from one acre mango orchard, i.e., in ON-YEAR is ₹ 46,000/ and in OFF YEAR ₹ 27,600 (40% of the ON-YEAR production). Hence the total income in two years from one acre mango orchard is ₹ 46,000 + ₹ 12,970 = ₹ 58,970/- (average income per year is ₹ 29,485) and the net income from one acre Litchi orchard, i.e., in ON-YEAR is ₹ 53,500/ and in OFF YEAR ₹ 16,500 (50% of the ON-YEAR production). The total income in two years from one acre mango orchard is ₹ 81,000 + ₹ 18,400 = ₹ 99,400/- (average income per year is ₹ 49,700) which is still less than sericulture which generate ₹ 54,700 in one acre of land for irrigated condition in one year. Sericulture provides regular employment to the farmers. In sericulture 478 man days are required per acre per year where as in horticulture only 250 - 300 man days are sufficient for one acre orchard. So, sericulture ultimately checks the migration of population from rural areas to urban areas, thereby minimizes the population and pollution in urban areas by arresting the growth of slums in urban areas. Hence, sericulture can be considered as an essential tool for the rural development and improving the standard of living of human population of village level.

Keywords

Sericulture, Mango, Litchi, Comparative Study, Murshidabad District.

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