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Muga silkworm is one of the most economically and culturally important insect found in northeastern region and has immense future potential for entrepreneurship development owing to its sericogenic nature. The distribution of Muga SilkWorm (MSW) in wild are extremely important determinant for rearing a disease resistant domesticated variety that can significantly improve the yield of the later in terms of silk production. This paper aims to explore the distribution of the wild MSW in northeastern part of India in connection with the distribution of its primary host plant viz., Litsea monopetala (LM) Soalu in wild. Species Distribution Models (SDMs) have been used to know the potential distribution of MSW in historical climate scenario and also the impact of future climate has been assessed using a two climate models (CMCC-ESM2 and HadGEM3) with two different scenarios (SSPs) for each model. The climate space was defined in two dimensional space using Principal Component Analysis (PCA) to simplify the models. Altogether two model algorithms were used to get the final ensemble model for both the MSW and the two primary host plants. The model performed for MSW was found to be good with average AUC value greater than 0.80. On the contrary, the model performed for Litsea monopetala was found to be excellent with average AUC value greater than 0.90. Similarly, the ensemble models performed using future climatic data under the CMCC-ESM2 and HadGEM3 models for MSW have shown AUC values within acceptable range (0.78-0.82), whereas, model of the host plant (LM) have shown AUC values in higher range i.e. within excellent model category (0.90-0.95). Thus, in this reduced climate dimension, the potential distribution of the MSW and LM have been compared among current and future climate scenarios of two different models and district wise distribution potential has been calculated. The overlapping potential habitat of the invasive plant MSW and its host plant LM in Northeast India, particularly Assam and Arunachal Pradesh, is projected to experience significant and critical changes under future climate conditions between 2040 and 2060. The present research identifies climate-driven habitat changes, which may impact host plant availability and, in turn, silkworm survival and silk production. The results also highlight the importance of climate-resilient sericulture policy, adaptive agriculture practices, and conservation strategies to maintain Muga silk production under changing environmental conditions.

Flacherie is a major bacterial disease causing >40% loss during Muga summer crops. For finding the root causes of the diseases, relationships were established between rearing and production data corresponding to land use/land cover, land surface temperature and meteorological parameters. Adverse affects were found in farms associated with anthropogenic activities, in contrast to forest cover which shows a negative trend. Muga disease early warning system, a mobilebased application and dashboard has been developed to predict rate of flacherie infestation at least 5–10 days in advance, for proper precautionary measures by the farmers to avoid disease outbreak and crop loss.

Background Insect gut microbiomes play a fundamental role in various aspects of insect physiology, including digestion, nutrient metabolism, detoxification, immunity, growth and development. The wild Muga silkworm,  Antheraea assamensis  Helfer holds significant economic importance, as it produces golden silk. Methods and results In the current investigation, we deciphered its intricate gut bacteriome through high-throughput 16S rRNA amplicon sequencing. Further, to understand bacterial community dynamics among silkworms raised under outdoor environmental conditions, we compared its gut bacteriomes with those of the domesticated mulberry silkworm,  Bombyx mori  L. Most abundant bacterial phyla identified in the gut of  A. assamensis  were Proteobacteria (78.1%), Bacteroidetes (8.0%) and Firmicutes (6.6%), whereas the most-abundant phyla in  B. mori  were Firmicutes (49–86%) and Actinobacteria (10–36%). Further, Gammaproteobacteria (57.1%), Alphaproteobacteria (10.47%) and Betaproteobacteria (8.28%) were the dominant bacterial classes found in the gut of  A. assamensis . The predominant bacterial families in  A. assamensis  gut were Enterobacteriaceae (27.7%), Comamonadaceae (9.13%), Pseudomonadaceae (9.08%) Flavobacteriaceae (7.59%) Moraxellaceae (7.38%) Alteromonadaceae (6.8%) and Enterococcaceae (4.46%). In  B. mori , the most-abundant bacterial families were Peptostreptococcaceae, Enterococcaceae, Lactobacillaceae and Bifidobacteriaceae, though all showed great variability among the samples. The core gut bacteriome of  A. assamensis  consisted of Pseudomonas, Acinetobacter, Variovorax, Myroides, Alteromonas, Enterobacter, Enterococcus, Sphingomonas, Brevundimonas, Oleispira, Comamonas, Oleibacter Vagococcus, Aminobacter, Marinobacter, Cupriavidus, Aeromonas, and Bacillus. Comparative gut bacteriome analysis revealed a more complex gut bacterial diversity in wild  A. assamensis  silkworms than in domesticated  B. mori  silkworms, which contained a relatively simple gut bacteriome as estimated by OTU richness. Predictive functional profiling of the gut bacteriome suggested that gut bacteria in  A. assamensis  were associated with a wide range of physiological, nutritional, and metabolic functions, including biodegradation of xenobiotics, lipid, amino acid, carbohydrate metabolism, and biosynthesis of secondary metabolites and amino acids. Conclusions These results showed great differences in the composition and diversity of gut bacteria between the two silkworm species. Both insect species harbored core bacterial taxa commonly found in insects, but the relative abundance and composition of these taxa varied markedly.

Aim: To identify and characterize the bacterial pathogens associated with bacteriosis in muga silkworm, A. assamensis. Methodology: The mid gut of diseased silkworm, A. assamensis was dissected and bacterial pathogens were cultured. Bacterial pathogens were identified by 16S rRNA gene sequencing. Insect bioassay studies were conducted to understand the pathogenicity of bacterial isolates. Results: Bacterial pathogens were identified as Pseudomonas aeruginosa and Bacillus mycoids. Under laboratory conditions, approximately 70% mortality of A. assamensis larvae was due to P. aeruginosa, while 50% larval mortality was due to B. mycoids. Interpretation: P. aeruginosa was relatively more pathogenic to A. assamensis than B. mycoids. Further, a graph on disease progression was developed to understand the trajectory of bacteriosis in A. assamensis. Key words: Bacteriosis, Disease progression, Muga silkworm, Pseudomonas sp., 16S rRNA sequencing

Development of multidrug resistance in infectious microbes is a common phenomenon and hence the search for alternatives with better activity continues. Silkworm antimicrobial peptides have been quite resourceful in this aspect as they are known to be potent against various bacteria, viruses and fungi. This study assesses the antimicrobial potentials of the peptides isolated from Bacillus thuringiensis immunised 5th instar lava of the Muga silkworm ( Antheraea assamensis ). The proteins produced as a result of immunization were isolated from the haemolymph and purified partially by acid-methanolic extraction which was then subjected for separation and purification by semi preparative RP-HPLC. The collected fractions were analysed for purity by SDS-PAGE following which, antimicrobial activity assay was performed against Gram-positive ( Bacillus thuringiensis ) and Gram-negative bacteria ( Escherichia coli ). Among the obtained eight purified fractions, seven fractions showed different ranges of antimicrobial activity. Amongst them, two fractions were seen to show antimicrobial activity against both Gram positive as well as Gram negative bacteria.

Muga silkworm is endemic to Assam and adjoining areas in North-Eastern India, and naturally produces golden silk. From time immemorial, many ethnic and tribal groups have produced muga silk. Muga silkworms are mostly wild unlike the mulberry silkworm, which is completely domesticated. The muga silkworm is a single species with little genetic variation among populations, survives harsh climatic conditions and is subject to various diseases, pests and predators. Due to the high incidence of disease and natural enemies, and variations in climatic conditions, the production of muga silk has recently declined dramatically. In order to improve the productivity of this silkworm it is important to have a better knowledge of both its host plants and biology. Lack of knowledge of its genetics and host plants is a major bottleneck. This paper reviews various aspects of muga silkworm culture, including the availability of different populations, and methods used to select for improvement in survival, cocoon yield, disease resistance, conservation and egg production.

ABSTRACT Muga silk worm (Antheraea assama West wood) is reared on leaves of som plant (Machilus bombycina King) because of their high nutritional value. Rearing becomes difficult due to attack of large number of insect-pests on som plant. Leaf miner (Phytomyza spp.) (Diptera: Agromyzidae) is a major pest and very harmful to som plant leaves. From observation it is found that leaf miner was found active throughout the year on som plant leaves. higher population level was maintained during 27th standard week to 34th standard week that is during 1st week of July to last week of August with highest population (20.42 larvae/5 leaves) recorded on 32nd standard week that is on the 2nd week of August. Leaf miner population had a significant positive correlation with temperature and relative humidity. A mixed formulation of imidacloprid with azadiraction was found to be the most effective against leaf miner showing 79.24% mortality with imidacloprid 76.25% and in the mixed formulation imidacloprid+polygonum 73.74 %. It is concluded that lower dose of imidacloprid mixing with azadiractin/polygonam/spilanthes extracts will be environmentally sound and eco-friendly and is recommended for leaf miner control to promote organic farming.

Muga silkworm is endemic to North-East India. The quality of primary host plant, i.e. Som. ( Persea bombycina Kost.), greatly affects the quality of cocoon and silk production. Som is susceptible to different foliar diseases caused by fungi, which can reduce the yield of leaf from 13.8 to 41.6% annually. So, a comprehensive mycofloral study of the host plant is important to forecast future diseases and design different disease management procedures. This study has been done for a period of 2 years from 2014 to 2016 in Goalpara district of Assam, India. Mycoflora of pedosphere (rhizosphere and non-rhizosphere), phyllosphere and aerosphere were identified and correlated with the seasonal variation. The rhizosphere, air and phylloplane were dominated by Rhizopus stolonifer (22.13%; 15.08%; 24.01%), while Aspergillus niger (12.63%) dominated non-rhizospheric soil. In summer, soil was majorly dominated by A. niger , Aspergillus fumigatus and Curvularia lunata , while R. stolonifer , Aspergillus clavatus and Penicillium chrysogenum dominated the winter soil. Pestalotiopsis disseminata is one of the major pathogens of Som and was found highest in aerosphere followed by phyllosphere. Temperature between 25 and 28 °C with 70–80% of relative humidity favours P. disseminata . This study provides a deep insight into the fungal diversity of Som with respect to pedosphere, aerosphere and phyllosphere, and this knowledge can be used to better select the plantation area and design different disease management strategies to sustain and proliferate the industry for socioeconomic development and to conserve its cultural essence.