Wild Silk Research Articles

Sharp decline in male fertility in F2 hybrids of the female-heterogametic silk moth Bombyx.

Sexual selection drives rapid evolution of morphological, physiological, and behavioral traits, especially in males, and it may also drive the rapid evolution of hybrid male sterility. Indeed, the faster male theory of speciation was once viewed as a major cause of Haldane's rule in male-heterogametic XY taxa, but is increasingly being replaced by the genetic conflict hypothesis partly because it cannot explain the faster evolution of hybrid female sterility in female-heterogametic ZW taxa. The theory nonetheless predicts that there should be more genes for hybrid male sterility than for hybrid female sterility even in such taxa, but this remains untested. Thus, finding evidence for the faster male theory of reproductive isolation beyond the F1 generation in ZW systems still represents a challenge to studying the impact of sexual selection. In this study, we examined F2 hybrids between the domesticated silkworm Bombyx mori and the wild silk moth Bombyx mandarina, which have ZW sex determination. We found that although only females showed reduced fertility in the F1 generation, the F2 hybrid males had a significant reduction in fertility compared with the parental and F1 males. Importantly, 27% of the F2 males and 15% of the F2 females were completely sterile, suggesting the presence of recessive incompatibilities causing male sterility in female-heterogametic taxa.

From Ancient Threads to Colonial Commerce: The Evolution of West Bengals Silk Industry from Mythical Origins to Independence

Silk production, or sericulture, has a rich history that is frequently eclipsed by its modern applications. Sericulture began in ancient China approximately 3000 BC and this was a well held secret until it spread to Korea, India and eventually the West through a variety of causes, including royal intrigue and missionary endeavours. By the Han Dynasty, silk had evolved from a luxury item to a valuable economic asset, impacting trade and culture throughout Asia and Europe. India's silk industry, as documented in ancient scriptures, progressed from early wild silk production in the Himalayan foothills to sophisticated mulberry sericulture by the 2nd century BCE. The Mughal dynasty improved Indian silk traditions by incorporating several weaving techniques and nurturing a thriving business in Kashmir and Bengal. From 1612 to 1858, the East India Company capitalised on Bengal's silk potential by building trading centres and using Piedmontese reeling technology to improve quality. Despite initial hurdles, Bengal silk became a major export commodity, but colonial policies and technological shifts eventually led to its demise. Silk output fell dramatically after independence due to a variety of economic and geopolitical issues. This article investigates the growth of India's silk industry, focussing on Bengal's key role and examines the effects of colonial control, technological advancements and the sector's trajectory up to Independence.

Wild silk insect of Simlipal biosphere and its molecular genetic diversity for conservation.

Designated silkworms (Antheraea mylitta D.) are found in the Smilipal Biosphere Reserve (SBR) and consist of four ecological groups. This study examined the genetics of eight ethnic groups from four ecological groups (Modal, Nalia, Bogai and Jata) using RAPD and ISSR markers. The RAPD primer produced 127 bands, of which 41 out of 116 polymorphic regions had a PIC value above 0.45. ISSR markers assigned PIC data values to 57 of 127 polymorphic sites. Cluster analysis revealed genetic differences between ecological populations, with markers separating ecological populations into groups. Low testicles and high genetic diversity indicate that these individuals are at different levels. If adequate protection is not provided, the risk of extinction of ecospecies designed in SBR increases. This study shows that the combined use of RAPD + ISSR markers can improve the results of the technology in identifying different diseases in situations where genomic information is limited.

Day-night gene expression reveals circadian gene disco as a candidate for diel-niche evolution in moths.

Temporal ecological niche partitioning is an underappreciated driver of speciation. While insects have long been models for circadian biology, the genes and circuits that allow adaptive changes in diel-niches remain poorly understood. We compared gene expression in closely related day- and night-active non-model wild silk moths, with otherwise similar ecologies. Using an ortholog-based pipeline to compare RNA-Seq patterns across two moth species, we find over 25 pairs of gene orthologs showing differential expression. Notably, the gene disco, involved in circadian control, optic lobe and clock neuron development in Drosophila, shows robust adult circadian mRNA cycling in moth heads. Disco is highly conserved in moths and has additional zinc-finger domains with specific nocturnal and diurnal mutations. We propose disco as a candidate gene for the diversification of temporal diel-niche in moths.

Muga (Antheraea assamensis) silk electrospun scaffold for biomedical applications

Abstract Wild silk varieties are less explored in the field of biomaterials than cultivated mulberry silk (Bombyx Mori). In the present work, an electrospun scaffold was produced from wild silk, muga (Antheraea assamensis), and it was assessed for the properties required for biomaterials. Scanning electron microscopy images showed that the electrospun fibers were formed without beads, and the majority of the fibers had diameters in the range of 500–900 nm. The scaffold started to decompose at 210 °C, which is higher than the temperature used for sterilization of the scaffold. The PBS uptake percentage was found to be 400 %, which is sufficient for the absorption of the medium used during cell culture. The scaffold had a hemolysis value of less than 5 %, which indicates that the scaffold exhibits good blood compatibility. The MTT assay showed cell viability of more than 80 % after 24 h and 48 h, and fluorescence microscopy showed that cells adhered and spread on the surface of the scaffold. The results show that muga silk electrospun mat can be used as an ideal biomaterial.

A Study on Cruelty Faced by Silkworms in the Production of Silk

Silk is the fiber that silkworms weave to make their cocoons which are the outer casings that protect them during the pupal stage. But most of the insects used by the silk industry don’t live past this stage, because they are boiled or gassed alive inside their cocoons, which causes the cocoons to begin unraveling so that workers can obtain the silk threads. Some 6,600 silkworms are killed to make just 1 kilogram of silk. The CSB (Amendment) Act, Rules and Regulations have been notified by the Govt. of India to bring quality standards in silkworm seed production. The objective of the research is to create awareness on the cruelty faced by silkworms in the production of silk. The research method used is empirical research and simple random sampling method is used and the sample size is 200 responses and the sample frame is in and around Valluvar kottam. The independent variables are age, gender, education qualifications, occupation and locality. The alternative to this cruel practice is to use another method of obtaining silk called ahimsa silk or wild silk, it is a method of nonviolent silk breeding and harvesting. Wild silk moths are bred, rather than the domestic variety. Roughly 3,000 silkworms are killed to make a single pound of silk. That means that billions, if not trillions, of them are killed for this every year. In order to avoid this practice of killing silkworms we should use an alternative type of fabric or use wild silk

Cocoon Care : Transformative Monitoring For Sericulture

Sericulture is the process of cultivating silkworms and extracting silk from them. The caterpillars of the domestic silk moth (also called „Bombyx Mori‟) are the most commonly used silkworm species in sericulture. Other types of silkworms (such as Eri, Muga, and Tasar) are also cultivated for the production of „wild silks‟. Silk is known as the queen of textiles due to its softness, durability, and luster. Furthermore, the silk fibers provide characteristics that are superior toany other type of fiber (e.g., water absorbency, heat resistance, dyeing efficiency, and luster). This textile is obtained from cocoons spun by larvae known as silkworm (Bombyx mori), which were discovered in China between 2600 and 2700 BC. The process of silk production is known as sericulture, beginning with the rearing of the silkworm1

Dyeing of Tussah Silk with Reactive Dyes: Dye Selection, Dyeing Conditions, Dye Fixation Characteristics, and Comparison with Mulberry Silk.

Tussah silk is one of the most widely used wild silks. It is usually dyed with acid dyes, despite the shortcoming of poor wet fastness. Reactive dyeing is a good solution to this problem. In our work, sulfatoethylsulfone (SES), sulfatoethylsulfone/monochlorotriazine (SES/MCT), monochlorotriazine (MCT), and bis(monochlorotriazine) (Bis(MCT)) dyes were used to dye tussah silk. All of these dyes showed lower exhaustion and fixation on tussah silk than on mulberry silk under alkaline conditions. Among them, SES dyes were more applicable, with a fixation of 70-85% (at 4%owf dye) at 90 °C when using sodium bicarbonate as an alkali. SES dyes also showed a rapid fixation speed. The dyeing of tussah silk required lower sodium bicarbonate dosage, the use of more neutral electrolytes, and a higher dye quantity to achieve deep effects compared to mulberry silk. Dyed tussah silk displayed lower apparent color depth and brilliance than dyed mulberry silk. The neutral boiling dyeing of tussah silk with SES dyes exhibited higher exhaustion, higher fixation (82-92% at 4%owf dye), and a slower fixation speed compared with alkaline dyeing. Furthermore, in this dyeing method, SES dyes showed higher and more efficient fixation on tussah silk than on mulberry silk. All dyed tussah silk had excellent color fastness to soaping.

Patterns of speciation in a parapatric pair of Saturnia moths as revealed by target capture.

The focus of this study has been to understand the evolutionary relationships and taxonomy of a widely distributed parapatric species pair of wild silk moths in Europe: Saturnia pavonia and Saturnia pavoniella (Lepidoptera: Saturniidae). To address species delimitation in these parapatric taxa, target enrichment and mtDNA sequencing was employed alongside phylogenetic, admixture, introgression, and species delimitation analyses. The dataset included individuals from both species close to and farther away from the contact zone as well as two hybrids generated in the lab. Nuclear markers strongly supported both S. pavonia and S. pavoniella as two distinct species, with hybrids forming a sister group to S. pavoniella. However, the Maximum Likelihood (ML) tree generated from mtDNA sequencing data presented a different picture, showing both taxa to be phylogenetically intermixed. This inconsistency is likely attributable to mitonuclear discordance, which can arise from biological factors (e.g., introgressive hybridization and/or incomplete lineage sorting). Our analyses indicate that past introgressions have taken place, but that there is no evidence to suggest an ongoing admixture between the two species, demonstrating that the taxa have reached full postzygotic reproductive isolation and hence represent two distinct biological species. Finally, we discuss our results from an evolutionary point of view taking into consideration the past climatic oscillations that have likely shaped the present dynamics between the two species. Overall, our study demonstrates the effectiveness of the target enrichment approach in resolving shallow phylogenetic relationships under complex evolutionary circumstances and that this approach is useful in establishing robust and well-informed taxonomic delimitations involving parapatric taxa.

Combined application of plant extracts (tannic acid and baicalin) with acid dyes in the simultaneous dyeing and finishing of tussah silk for enhanced antioxidant, antibacterial and UV protective properties

The one-step dyeing and finishing of tussah fiber have advantages of short process, high efficiency, and energy and water saving. Additionally, to upgrade the functionalities of tussah silk fiber using natural chemicals with environmental benefits can increase its applicability. In this work, the combined application of plant extracts and acid dyes was presented for simultaneously imparting colorful shades, antioxidant activity, antibacterial activity, and UV protection capability to tussah silk. The stability of tannic acid, baicalin, and their mixtures with acid dyes was first discussed, and the colors and functionalities of dyed and finished tussah silk were evaluated. Tannic acid had less effect on the colors of dyed tussah silk. C.I. Acid Blue 113 was not stable in hot baicalin solution, and its pre-heated mixture with baicalin dyed tussah silk to dull red hue rather than blue hue. The bright blue and green colors of tussah silk were obtained by dyeing with anthraquinone and triarylmethane dyes, but their hues were affected by baicalin due to the light yellow color of baicalin and the matching of colors. Tannic acid exhibited better antibacterial property than baicalin on tussah silk, while baicalin had better antioxidant and UV protection capability than tannic acid. This work demonstrates that the one-step dyeing and finishing of tussah silk with acid dyes and plant extracts are feasible. However, special attention should be paid to the color changes of individual dyes for pale dyeing.

Inundative practice for screening siRNA management candidates against a notorious predatory beetle using olfactory silencing

Calosoma maximoviczi, a predatory pest beetle, poses a significant threat to wild silk farm production due to its predation on wild silkworms. Given the coexistence of this species with beneficial silkworms in the farm orchards, chemical pesticides are not an ideal solution for controlling its population. In this study, we employed a comprehensive multi-target RNA interference (RNAi) approach to disrupt the olfactory perception of C. maximoviczi through independently silencing 16 odorant receptors (ORs) in the respective genders. Specifically, gene-specific siRNAs were designed to target a panel of ORs, allowing us to investigate the specific interactions between odorant receptors and ligands within this species. Our investigation led to identifying four candidate siOR groups that effectively disrupted the beetle's olfactory tracking of various odorant ligands associated with different trophic levels. Furthermore, we observed sex-specific differences in innate RNAi responses reflected by subsequent gene expression, physiological and behavioral consequences, underscoring the complexity of olfactory signaling and emphasizing the significance of considering species/sex-specific traits when implementing pest control measures. These findings advance our understanding of olfactory coding patterns in C. maximoviczi beetles and establish a foundation for future research in the field of pest management strategies.

Characteristics Of Attacus atlas Cocon Collected from Tree of Mahoghony (Swietenia mahagoni) in Kembaran District

Attacus atlas is a wild silk type from the non-mulberry group, representing various fagara silkworms that produce cocoons. The produced cocoons have high economic value when utilized for commercial silk production. The distinctive characteristic of A. atlas silk fibers differs from Bombyx mori (mulberry) silk as the resulting fibers have a natural brown color without dyeing processes. The characteristics of cocoons significantly impact the resulting thread production. This study aims to obtain data on the characteristics and morphometrics of A. atlas cocoons located on mahogany trees providing road shade in Kembaran District. Observed characteristics include the weight of the intact cocoon skin, the weight of cocoon skin without floss, the weight of floss, cocoon diameter, cocoon circumference, cocoon length, and cocoon color. The collected data were then analyzed using descriptive analysis. The research shows that A.atlas cocoon skin characteristics vary greatly, demonstrated by the weight of the intact Cocoon Skin (0.66-2.35 g), the weight of Cocoon Skin without Floss (0.46-1.93 g), the weight of Floss (0.1-0.54 g), Cocoon Length (5.2-8.1 cm), Anterior Diameter (2.10-3.0 cm), Medial Diameter (2.30-3.4 cm), Posterior Diameter (2.20-3.1 cm), Anterior Circumference (6.20-9.50 cm), Medial Circumference (7.70-10.50 cm), Posterior Circumference (6.10-9.10 cm), and cocoon color classification into light (17 cocoons/15.9%), medium (66 cocoons/61.7%), and dark (24 cocoons/22.4%). The temperature, cocooning location, and gender of the cocoon are unknown, resulting in weight and morphometric value variations.

Life Cycle of Wild Silkmoth Attacus atlas L. Fed on Mahogany Leaves and Soursop Leaves

The study aims to investigate the life cycle and success of the Attacus atlas L. larvae fed with mahoni leaves and sirsak leaves. Observations are done on the development of larvae from eggs until they reach the adult butterfly phase. The study was conducted between November 2022 and January 2023 using direct observation methods to look at the life cycle of Attacus atlas L. Observations were carried out in the morning and in the evening. Data on the success rate of life of larvae in each stage of development is also recorded. Research has shown that the life cycle of A. atlas L. larvae on mahoni leaf foods has a shorter phase period compared to sirsak leaf feed. The age of the A. atlas L. larvae tends to be higher when feeding the sirsak leaves, especially in the subsequent instar phase. However, further research is needed to gain a more comprehensive understanding of the other factors that affect the success of the life of A. atlas L. larvae on various types of feed. This research contributes to the biological understanding and management of A. atlas L. larva conservation, as well as providing important insights into the conservation efforts of this species as a wild silk insect that has significant economic value.

Apelin-Overexpressing Neural Stem Cells in Conjunction with a Silk Fibroin Nanofiber Scaffold for the Treatment of Traumatic Brain Injury.

Traumatic brain injury (TBI), especially moderate or severe TBI, is one of the most devastating injuries to the nervous system, as the existing therapies for neurological defect repair have difficulty achieving satisfactory results. Neural stem cells (NSCs) therapy is a potentially effective treatment option, especially after specific genetic modifications and when used in combination with biomimetic biological scaffolds. In this study, tussah silk fibroin (TSF) scaffolds with interconnected nanofibrous structures were fabricated using a top-down method. We constructed the apelin-overexpressing NSCs that were cocultured with a TSF nanofiber scaffold (TSFNS) that simulated the extracellular matrix in vitro. To verify the therapeutic efficacy of engineered NSCs in vivo, we constructed TBI models and randomized the C57BL/6 mice into three groups: a control group, an NSC-ctrl group (transplantation of NSCs integrated on TSFNS), and an NSC-apelin group (transplantation of apelin-overexpressing NSCs integrated on TSFNS). The neurological functions of the model mice were evaluated in stages. Specimens were obtained 24 days after transplantation for immunohistochemistry, immunofluorescence, and western blot experiments, and statistical analysis was performed. The results showed that the combination of the TSFNS and apelin overexpression guided extension and elevated the proliferation and differentiation of NSCs both in vivo and in vitro. Moreover, the transplantation of TSFNS-NSCs-Apelin reduced lesion volume, enhanced angiogenesis, inhibited neuronal apoptosis, reduced blood-brain barrier damage, and mitigated neuroinflammation. In summary, TSFNS-NSC-Apelin therapy could build a microenvironment that is more conducive to neural repair to promote the recovery of injured neurological function.

Bio-coloration and ultraviolet protection finishing of tussah silk using chestnut leaf extract and its thermodynamic study

This study investigates the dyeing effects of chestnut leaf extract on tussah silk and aspires to create bio-colored and ultraviolet-resistant textiles. The results proved that post-mordanting with aluminum potassium sulfate and ferrous sulfate yielded better results than direct dyeing, the color strength value with ferrous sulfate mordant reached 10.9, and the color fastness of tussah silk with post-mordanting was rated above 4. Furthermore, the ultraviolet protection factor values reached 17, 39, 45, and 53 with control, direct dyeing, and post-mordanting with aluminum potassium sulfate and ferrous sulfate, respectively, revealing that the chestnut leaf extract could be a potential ultraviolet protection agent to increase the ultraviolet protection performance on tussah silk. In addition, the adsorption process and thermodynamic characteristics of chestnut leaf extract on tussah silk were examined. The results suggested that the Langmuir isotherm model adequately described the thermodynamic behavior of chestnut leaf extract on tussah silk. The positive enthalpy change indicated that the adsorption process was an endothermic process.

Research on the Characteristics and Development of Liaoning Tussah Silk

Based on research conducted from multiple perspectives, including the earliest origin and development of tussah, natural ecological and climatic resources in the tussah region, tussah cocoons and professional techniques for processing and weaving tussah silk, as well as the characteristics, classification, and use of tussah silk fabrics, it is summarized that tussah, tussah silk, and their production and production processes have been inherited and spread through the wisdom and wisdom of generations of the people for thousands of years, and have produced a systematic system of tussah, cocoons, silk principles and practical experience in silk production. Liaoning tussah silk fabric has a unique style, unique craftsmanship, wide range of uses, and profound significance. It is an irreplaceable textile and holds an important position in the country and even the world.

Supply chain integration through network optimization to facilitate dynamic entity addition for a wild silk industry

Supply chain integration through network optimization to facilitate dynamic entity addition for a wild silk industry

Moth to Cloth: Silk in Africa

Moth to Cloth: Silk in Africa

Fabrication of air‐conditioning tussah silk with capric–stearic eutectic mixture for effective energy storage and thermal‐regulatory applications

AbstractUnder the urgent demand of effective energy‐storage and thermal‐regulatory textile fabrics, the air‐conditioning tussah silk as a new arrival is endowed with this excellent property by coupling with the phase change material of capric acid–stearic acid eutectic mixture. In addition, the facile pad‐dry‐cure technique used with the assistance of ultrasonic waves efficiently avoided the problems of the sophisticated process and low efficiency in traditional post‐finishing methods with phase change microcapsules. With optimal preparation conditions, the resultant tussah silk exhibited a superior thermal reliability and thermoregulatory character along with a phase enthalpy of 31.80 J g−1 at a phase change temperature of 24.01 °C. Meanwhile, the tested air permeability, mechanical properties and washing fastness showed its favorable thermal and wear comfort. Benefitting from these admirable merits, this air‐conditioning tussah silk with tunable heat storage and release performance could automatically respond to external temperature stimuli, finally contributing to practical application in intelligent protective garments. The intelligent bidirectional temperature‐adjusting property corresponding to the efficient management of human skin temperature is beneficial for constructing a comfortable microclimate for the human body. In brief, our study provides a novel heat‐storage and temperature‐regulating textile with tussah silk as well as unique natural advantages by means of a simple preparation method. © 2022 Society of Industrial Chemistry.

Keanekaragaman Ngengat Superfamily Bombicoidea: Eksplorasi Potensi Ulat Sutera di Dataran Rendah Kabupaten Jayapura

Jayapura Regency is one of the regions that considerable potential for economic growth from non-timber forest products. In the development of non-timber forest products in the form of products produced by insects, silk yarn is one of the commodity that has a high demand. The domestic demand for silk yarn is 900 tons/year, while only 19.05 tons/year were produced in 2012. Jayapura Regency has a great potential to supply the shortage of cocoon for the domestic market and the wide open international market. Related to this challenge, this study conducted basic research on the diversity of moths from the Bombicoidea superfamily in the natural forest of Kampung Soaib, Jayapura Regency. Sampling using light traps, four species of moths from the Saturnidae family were obtained, Syntherata apicalis, Opodiphtera intermedia, Opodiphtera papuana, and Coscinocera hercules. The cocoon of Coscinocera hercules is very potential as a silk thread producer because it is large and consists of two layers with brown color and has fiber characteristics similar to the cocoon of Attacus atlas which has been developed as a wild silk producer. These results indicate that the lowland forests of Jayapura Regency as a habitat for wild silkworm species has potential to be developed as non-timber forest products.Key words: Superfamily Bombicoidea; silkworm; cocoon; Jayapura regency