Silkworm Races Research Articles

Sericulture in Jammu and Kashmir- A Review

Sericulture is considered as an age old occupation in Jammu and Kashmir. J&K has enormous potential for silk production empowering the farmers of J&K by increasing their income and employment (Dar et al., 2021).The raw silk produced in J&K is recognized across the globe. The size of land holding is less for sericulture activity compared to horticulture and agroforesrty. Farmers from about 20 districts of J&K take sericulture as the subsidiary occupation. Spring season crop (May-June) is the main crop in this region followed by second crop during September- October (Chouhan et al., 2016). Important mulberry varieties cultivated are Goshoerami, Ichinose, KNG, Kukusou 21, Sujanpur and Chak Majra (Shabnam et al., 2016). Silkworm races of commercial importance are DUN22, NB4D2, SK6, SKUAST-31, CSR18 and DUN6 (Buhroo et al., 2017). Sericulture is taken as a subsidiary occupation by about 33,000 rural households in J&K. Most of these families are economically backward and sericulture plays a crucial role for their livelihood. In order to empower these farm families productivity and quality of cocoons need to be improved by applying scientific package of practices. (Bhat et al., 2020). Inadequacy of mulberry leaves and lack of awareness on scientific technologies, ineffective marketing strategies are the hurdles for the progress of sericulture industry in J&K.

PROTEIN ANALYSIS FROM DIFFERENT BODY TISSUES OF THREE IMPORTANT COMMERCIAL RACES OF MULBERRY SILKWORM BOMBYXMORI(L)BY USING BRADFORD METHOD

The mulberry silkworm Bombyxmori L. is one of the economically beneficial insect. Natural silk is produced by silkworm which converts mulberry leaf protein in to silk. Three mulberry silkworm races viz.,two single hybrid FC1(CSR6×CSR26), FC2(CSR2×CSR27)and one bivoltinedouble hybrid FC1× FC2[(CSR6×CSR26) × (CSR2×CSR27)] were selected for the present study. The main aim of present study was made an attempt to analyse and compare the protein content in Haemolymph, Midgut, Silkgland and Fatbodyselected silkworm races of fifth instar larvae. Data obtained were statistically analysed with two way ANOVA method at (p<0.001), (p<0.005) and (p<0.05) level of significance. High level of significance (p<0.001)were recorded in silkgland compared to haemolymph, midgut and fatbody in all selected silkworm races whichcomparing the protein content in haemolymph and midgut of all selected silkworm FC1× FC2races shows (p<0.001) significance compared to FC1 (p<0.005) and FC2 (p<0.05), protein content in silkgland and fat body shows (p<0.001) in FC1× FC2 compared to FC1 and FC2respectively. The results therefore, showed bivoltinedouble hybrid silkworm is superior in protein content in all examined different tissues and the study would be of great help to farmers to choose the better silkworm races for rearing purpose.

Modulations of Haemolymph Parameters in Fifth Instar Silkworm Bombyx Mori L. Parasitized with Beauveria Bassiana

The study focused on understanding the impact of Beauveria bassiana infection on the haemotological parameters such as pH, specific gravity and rate of pulsation of the economically significant silkworm, Bombyx mori. Silkworms, due to centuries of domestication, have developed sensitivity to environmental conditions and various micro-pathogens affecting their nutrition, metabolism, and physiological aspects of haemolymph. The researchers used the bivoltine double hybrid silkworm race (CSR2 X CSR27) X (CSR6 X CSR 26) for the investigation. The results revealed that the pH levels of the haemolymph on the first day of the fifth instar in healthy silkworms were 6.615, and on the sixth day, they were 6.596. In the experimental batch, there was a drastic reduction from the first day (6.590) to the second day (6.253), which gradually increased until the fourth day (6.426) of the instar and gradually decreased on the fifth (6.398) and sixth days (6.374). A lower level of specific gravity of the haemolymph was noticed on the first day (1.024) of the 5th instar in silkworms inoculated with Beauveria bassiana. Then a gradual increase was observed till the sixth day (1.038) of the 5th instar. Conversely, in the healthy silkworms, there was a gradual decline in the specific gravity of the haemolymph from the first day (1.025) to the sixth day (1.012) of the fifth instar. The pulse rate in silkworms parasitized by Beauveria bassiana showed a significant increase from the first day (35) to the second day (48), followed by a gradual decrease to the sixth day (32) of the instar. But in control silkworms, the heart rate increased gradually from the first day (35) to the fifth day (45) of the instar and then suddenly decreased on the sixth day (38).

Dynamics of Nutritional Indices in Fifth Instar Silkworm Bombyx Mori L. Parasitized with Beauveria Bassiana

Silkworm Bombyx mori is a small economically significant insect. Due to domestication for centuries, silkworms have become very gentle and subtle to the environmental conditions and micro-pathological agents which affect its metabolism, the food intake, dietary utilization, dietary efficiency, morpho-nutritional parameters such as olfactory organs and gene expression in the silkworm. Hence, the present research was focused to comprehend the dynamic changes in the nutritional parameters amalgamating the effects of infection of Beauveria bassiana in 5th instar silkworm compared to untreated silkworms. For the current investigation, the popular silkworm race bivoltine double hybrid (CSR2 X CSR27) X (CSR6 X CSR 26) was chosen. Various nutritional parameters such as ingestion of mulberry leaf, digestion, excretion, approximate digestibility, consumption index and reference ratio were estimated based on the dry weight of mulberry. The results indicated that food consumption, digestion of food ingested and excreta decreased in Beauveria bassiana parasitized silkworms. No significant variation was noticed in approximate digestibility and reference ratio from the first day to the fifth day of the instar, but on the sixth day, a significant drop in these two parameters was noticed compared to unparasitized worms. The consumption index was recorded higher in the experimental batch.

Study of Gaps in Adoption of Improved Tasar Silkworm (Antheraea mylitta D) Rearing Technologies

Maharashtra contributes paltry 0.76 per cent of the total production of tasar silk in the country, with 23 MT but the production of tasar silk in the state is found to be dwindling which might be due to the gaps in knowledge and adoption of improved tasar silkworm rearing technologies. Therefore, present investigation was undertaken to assess the gaps in adoption of tasar silkworm rearing technologies and constraints faced by the tasar farmers in adopting the recommended technologies. The study was conducted in Bhandara, Gondia and Gadchiroli districts of Maharashtra. The “Ex-post facto” research design was used for the study. A total 120 tasar silkworm rearing farmers were randomly selected for the study from those selected districts. The data was analyzed using SPSS software. The results showed that the major gaps in adoption were seen the practices such as Integrated Pest Management for the control of gall disease (91.67%), application of Farm Yard Manure (FYM) or vermi-compost @4 kg/plant or 2kg/plans twice in a year (87.50%) and foliar spraying of 1.5% urea twice @ 15 days’ interval before 30 days of rearing (78.33%) and these were ranked 1st, 2nd and 3rd, respectively. The average gaps in adoption were 52.71 per cent. Similarly, non-availability of quality seeds/Dfls for rearing, non availability of disease resistance/tolerant silkworm races, non-enhancement of seed cocoon/reelable cocoon prices due to non-availability of formal and fair market, no hand holding support during the crop failure from the government, outbreak of diseases due to weather fluctuation and difficulty in adoption of recommended package of practices due to insufficient fund were the major constraints experienced by the tasar silkworm rearers. Thus, proper research, extension, communication and training strategies are needed to be formulated so that the constraints faced in adoption will be removed and the gaps in adoption could be bridged in order to accelerate the rate of adoption of modern tasar silkworm technologies in state and, thus, increasing the scope for boosting the tasar silk production of the state in the years to come.

Extraction and Characterization of Sericin from Cocoon of Four Different Silkworm Races Bombyx Mori L.

The removal and use of sericin could have a strong economic, social, and environmental impact, particularly in countries where sericulture is practiced, especially in Bangladesh. Because in our country Bangladesh, sericin is a waste material in the sericulture industry. Several techniques have been adopted for sericin extraction, but maintaining its chemical properties after extraction and environment-friendly extraction methods are still a major challenge. Sericin is fully or partially hydrolyzed and solubilized during the degumming of the cocoon. Consequently, it is important to create sericin extraction procedures that require less energy, don't release any chemicals, and don't harm the environment. Numerous research has been done to extract sericin but the differences in sericin content and chemical properties of Bivoltine and Multivoltine silkworm cocoon have not been studied yet. In this work, sericin was extracted from the silkworm cocoon of four different silkworm races at two different temperatures and durations. Significant differences were observed in yield% with different silkworm races and different treatments. Extracted sericin was characterized through SDS PAGE, FTIR & UV spectroscopy, and TGA.

Perception of Tasar Silkworm Rearers about the Climate Change Impact on the Tasar Silk Production of Maharashtra

Tasar sericulture is one of the allied sectors of agriculture which is a climate sensitive sector. Understanding farmer’s perception about the climate change impact on the rearing performance tasar silkworm is a key to the development of new climate tolerant technologies so as to encourage the other farmers for adopting sericulture eventually to boost the production of the tasar silk production in the state. Thus, the study was designed to establish farmer’s perception on climate change and its impacts on tasar silkworm rearing performance. The study was conducted in all four tasar silkworm rearing districts of Maharashtra namely Bhandara, Gondia, Gadchiroli and Chandrapur. A total 160 tasar silkworm rearers were selected randomly from all the four districts. Information was collected from each tasar silkworm rearers through Rapid Rural Appraisal (RRA) and focus group discussions (FGD). Climate Change Perception Index (CCPI) and Climate Change Impact Perception Index (CCIPI) were used to assess the perception about the impact of climate change on tasar silk production. Weighted Average Index (WAI) was used to analysis the impact. Results showed that majority of the respondents perceived that the yield and production of tasar cocoons production has reduced compared to last ten years. Moreover, frequent loss of the crop is noticed due to sudden change in the climatic conditions during the rearing of silkworm. Similarly, the high incidence of diseases and pest is also noticed thereby affecting the income generation of the tribal tasar farmers of the state. The results of the study will be useful for formulating appropriate policy against the ill-effects of the climate change. The results will also give impetus to the researcher to develop the thermo tolerant and climate change tolerant or resistant varieties or races of tasar silkworm so as to boost the tasar silk production of the state.

Screening of Suitable Castor Cultivars for Ericulture in Tamil Nadu, India

Although castor cultivation is predominant in Gujarat, Andhra Pradesh, Tamil Nadu, and few other states in India, rearing of eri silkworm, which feeds on castor is not catching up in these non-traditional states. One of the probable reasons is the non-availability of studies indicating region-specific suitable castor cultivars for different eri silkworm races. Studies on castor cultivar preference for one such better-performing race, C2 yielding better shell weight (12-15 Kg/100 DFL) in the Tamil Nadu region is lacking. Eleven castor cultivars, including local accessions, varieties, and hybrids, have been raised in Randomised Block Design (RBD) with three replicates. The worms were reared using all the grown cultivars with five replications for each cultivar (treatment) with 20 worms/replication. All the economic parameters of eri silkworm were computed and compared. Local accessions such as Krishnagiri local and Tindivanam local, Perennial castor - YTP – 1, and Hybrids such as YRCH – 1 and DCH – 519 recorded significantly better larval, cocoon, and reproductive parameters. Least larval duration and highest matured larval weight were recorded in Krishnagiri local accession. Least values of all the economic parameters were noticed in Dharmapuri local. The reason might be due to the poor leaf quality impacted due to severe whitefly (Trialeyrodes ricini) and red spider mite (Tetranychus urticae) attack.

Disease incidence, larval parameters and mortality of mulberry silkworm, Bombyx mori L. effected by bed disinfectants

With an aim to find out an effective bed disinfectant regulating disease incidence, larval growth parameters and mortality of mulberry silkworm, Bombyx mori L. revealed a positive influence on the disease incidence, and larval growth of mulberry silkworm race, (CSR6 × CSR26) × (CSR2 × CSR27). The commercial bed disinfectant, Ankush manifested better result in terms of reduction in disease incidence (1.833 %) and larval parameters (larval duration, 21.888 days; full grown larval weight, 4.596 g; silk gland weight, 0.889 g and 24.181% SGTSI) compared to the control (22.667 days, 3.976 g, 0.817 g and 20.726 %, respectively) followed by Sericillin and Turmeric rhizome powder alone or in combinations. However, a combination of bed disinfectants viz., Ankush + Sericillin, Ankush + Turmeric rhizome powder and Sericillin + Turmeric rhizome powder recorded better results compared to Turmeric rhizome powder alone. Though bed disinfectants did not show any significant effect on mortality percentage but Ankush resulted highest reduction of mortality over control (46.933 %). The performance of all the bed disinfectants was found to be better during the late spring season.

Growth Attributes of Eco Races of Eri Silkworm, Philosamia Ricini Donovan in the Western Zone Conditions of Tamil Nadu

One of the most economic exploitation, widely cultivated, and financially viable non-mulberry silkworms is the eri silkworm (Philosamia ricini). The feeds that eri silkworms consume have a significant impact on their yield and silk production. A study was conducted to assess the growth characteristics of the eco races of the eri silkworm in the circumstances of western region of Tamil Nadu. The Central Muga and Eri Research Institute in Jorhat, Assam provided the eco races of eri silkworm. Three replications of the Completely Randomized Design (CRD) were used to set up the treatments. By feeding worms with castor leaves in the cellular rearing method, the growth characteristics of eco races of eri silkworm, specifically the larval parameter and cocoon parameter, were examined. Among the eco races of eri silkworm in comparison with standard F1 hybrid, the eco race Jonai recorded the maximum growth attributes such as larval weight (7.09 g), cocoon weight (3.93 g), shell weight (0.66 g), shell ratio, ERR (16.78 %) which was on par with F1 hybrid followed by Khanapara and Titabar. The least was observed in Barpathar and Adogiri. This study reveals that among ten eco races of eri silkworm, the eco race Jonai recorded performed well in western zone condition of Tamil Nadu and it can be commercially reared in alternative to Commercial F1 breed.

Activities of acid phosphatase and alkaline phosphatase in various silkworm races and correlation studies

Activities of acid phosphatase and alkaline phosphatase in various silkworm races and correlation studies

Adaptability and Comparative analysis of Economic and Biological Traits of various Silkworm Races (Bombyx mori L.)

Adaptability and Comparative analysis of Economic and Biological Traits of various Silkworm Races (Bombyx mori L.)

Impact of Botanical Extracts on Histopathology of Midgut of CSR2 Race of Mulberry Silkworm (Bombyx Mori L.) Inoculated by Staphylococcus Aureus

In the present study changes in midgut epithelium of 5th day of 5th instar silkworm race CSR2 infected with a gram-positive bacteria Styphalococcus aureus and plant extract treated group and control group were studied. Large numbers of newly developed cells appeared in the bacteria infected part of the midgut epithelium. After inoculation, and along with their development, the bacteria old columnar cells were discharged into the midgut lumen during development. On the other hand, in the uninfected portion of the midgut only a few cells developed, and no columnar cells were discharged. Similarly, the marked replacement of midgut epithelial cells during larval development were also observed in larvae treated by plant extract. In the larvae infected with S.aureus, the columnar cells lost their regenerative ability, and because of the exfoliation of infected columnar cells, the midgut epithelium consisted mainly of uninfected goblet cells at a late stage of infection. The degree of epithelial regeneration varied with the silkworm strain and the dosage of the bacteria.

Breeding of commercial silkworm race “Hakurei” with improvement of efficiency of mounting

Breeding of commercial silkworm race “Hakurei” with improvement of efficiency of mounting

Stage specific life table of mulberry silkworm race NB4D2 × SH6 at different temperatures under laboratory conditions

Stage specific life table of mulberry silkworm race NB4D2 × SH6 at different temperatures under laboratory conditions

Comparative Performance of Three Silkworm Races Fed on Local Mulberry against Biological and Commercial Parameters

Comparative Performance of Three Silkworm Races Fed on Local Mulberry against Biological and Commercial Parameters

A Study on Evaluation of Alkaline and Acid Phosphatase Isozymes During Different Developmental Stages of New Breeding Lines and Races of Bombyx mori L

It is interesting to note that different silkworm races reared in laboratory offer an important testing ground for the application of biochemical methods to taxonomic problems. Moreover, there is scarcity of knowledge on enzyme studies in new breeding lines and races of silkworm specially Bombyx mori L. Therefore, we designed the present study with the main goal to evaluate the activities of alkaline and acid phosphatases quantitatively during different developmental stages of new breeding lines and races viz. Kalimpong-A (KA), B18, Pure Mysore (PM), evolved R1 and R2 of Bombyx mori L. Quantitative estimations of in alkaline and acid phosphatases were expressed in terms of enzyme activity. Alkaline and acid phosphatase activities during the different developmental stages of KA, NB18, PM, evolved R1 & R2 races were determined using Sodium-1 naphthahyl phosphate as a substrate following the dye-coupling method. The assay mixture included 2 ml of substrate and 0.2 ml of enzyme extract and incubation was made for 30 minutes at 25°c. The reaction was stopped by adding 2 ml of post coupling solution (5 parts of 4% sodium dodecyl sulphate and 2 parts of 0.2% Fast red TR salt) and colorimetric determination were made at 540 nm. Results illustrated that the activity of phosphatases was found to be different and high activity was found in the larval stage, which is feeding stage followed by pupae.

Atypical voltinism in mulberry silkworm Bombyx mori L., 1758 (Lepidoptera: Bombycidae) races Barapat and Barapolu

The mulberry silkworm, Bombyx mori L., 1758 (Lepidoptera: Bombycidae) is classified as univoltine, bivoltine, and polyvoltine based on the annual brood frequency. Voltinism in B. mori is characterized by the occurrence of embryonic diapause (facultative and obligatory diapause). Univoltine silkworms suited to cold and temperate regions lay diapausing eggs and polyvoltine silkworms suited to tropical regions lay non-diapausing eggs. In contrast, the occurrence of diapause in bivoltine silkworms is influenced by the environment. In addition to the difference in the occurrence of embryonic diapause, larval duration, and cocoon characters show distinct variations. In the present correspondence, we are presenting an interesting observation from two silkworm races Barapath and Barapolu originating from the North-East region of India that display divergence in voltinism. The unique characteristic features of univoltine, bivoltine, and polyvoltine observed in the races are discussed explaining the occurrence.

Differences among the silkworm races in elution characteristics of cocoon-shell glutinous substances at the cocoon boiling

Differences among the silkworm races in elution characteristics of cocoon-shell glutinous substances at the cocoon boiling

1-Deoxynojirimycin and polyphenolic composition and antioxidant activity of different native Thai silkworm (Bombyx mori) larvae

1-Deoxynojirimycin (DNJ) and polyphenolic compound are extensively found at different levels in many silkworm races. The present investigation comprises, estimation of DNJ, polyphenol, total phenolic (TPC) and total favonoid contents (TFC), antioxidant activities (DPPH, ABTS, and FRAP). The results showed that the fifth larval instars of Samrong and Nangsiw had high content of DNJ (96.42 mg/100 g dw and 65.23 mg/100 g dw, respectively). Nangsiw had the highest content of quercetin (82.94 mg/100 g dw) and (+)-catechin (81.88 mg/100 g dw). Nangsiw contained relatively highest (p < 0.05) TPC and TFC and exhibited highest scavenging free radical DPPH activity (58.96%), and highest ABTS radical scavenging capacity (12.35 mg TE/100 g dw) and highest ferric reducingantioxidantpower (FRAP) (2.03 mg Fe(II)/g dw). This experiment suggests that Samrong and Nangsiw are a valuable source of natural alkaloid and phenolic antioxidants for commercial exploration.