Cocoon Weight Research Articles

Comparative Screening of Elite Bivoltine Silkworm Breeds under Summer Conditions of Kashmir

The success of the sericulture industry largely depends upon the quality of mulberry leaf and type of silkworm breed reared on these leaves. The rearing of season specific silkworm breeds can be instrumental in the successful rearing which will yield good cocoon crop and thereby leading to enhanced silk production. Data with respect to eleven economic parameters viz., fecundity, hatching percentage, larval weight, fifth instar larval duration, total larval duration, cocoon yield by number, cocoon yield by weight, single shell weight, single cocoon weigh, shell ratio and pupation rate was recorded, analysed statistically and subjected to multiple trait evaluation index. Significant differences were recorded in economic parameters but no specific silkworm breed performed best in all the economic parameters studied except SK-6 which performed best for most of the economic parameters, SK-1 and SK-28 showed best performance with respect to single cocoon weight and fecundity respectively. Out of nineteen silkworm breeds only nine breeds viz., SK-6, SK-28, SK-30, KSO, SK-22, SK-24, SK-1, SK-13 and CSR-4 were found promising with average evaluation index of 66.7, 58.8, 57.2, 56.6, 55.5, 54.5, 53.1, 52.6 and 50.7 respectively. These breeds could be utilized in appropriate combination in evolution of new breeds/ hybrids for the region.

Optimizing Eri Silkworm Productivity: Evaluating the Performance of Ecoraces of Samia ricini (Donovan) in the East Coastal Condition of Tamil Nadu, India

This study investigated raising Eri silkworms, Samia ricini (Donovan) a multi-voltine, domestic moth, traditionally bred indoors and known for its spun silk, in the eastern coast of Tamil Nadu, India. Eri silkworms typically thrive in the northeast regions, but the growing demand for Eri silk has led to exploring new locations for their production. The eight ecoraces of Eri silkworm i.e. C2, Borduar, Khanapara, Mendipathar, Dhanubanga, Nongpoh, Borduar and Titabar were selected for this study reared on castor plants under varied climatic conditions in Tamil Nadu. The economic and grainage characters such as larval duration, matured larval weight, survival rate, cocoon weight, shell weight, shell ratio, effective rearing rate, rate of pupation, rate of moth emergence, fecundity and hatchability were analyzed. This study revals that C2 ecorace consistently outperformed the other ecoraces, exhibiting superior growth parametrics, cocoon quality, and silk production potential.Findings indicate that optimal temperature and humidity conditions are crucial for enchancing performace, particularly for sensitive ecoraces like Barpathar and Nongpoh, highlighting the importance of ecorace selection and environmental management for sustainable eri silk production.

Influence of Natural Dyes on the Qualitative and Quantitative Parameters of Bivoltine Silkworm Breeds under Sub-Tropical Conditions of Poonch District, Jammu and Kashmir

The study on Influence of Natural Dyes on the qualitative and quantitative parameters of Bivoltine Silkworm Breeds under Sub-tropical Conditions of Poonch District, UT Jammu and Kashmir,” was conducted during the spring of 2022 at the PG, Department of Sericulture, Poonch Campus, University of Jammu. The study examined the effects of feeding bivoltine silkworm breeds CSR16 and CSR27 with two concentrations (50% and 100%) of natural dyes: madder (Rubia cardifolia) and indigo blue (Indigofera tinctoria). A comprehensive evaluation of both qualitative and quantitative parameters was undertaken, including fecundity, hatching %, larval duration, weight of 10 mature larvae, survival rate, mortality %, pupation % and cocoon quality parameters. The results indicated significant enhancements in fecundity, hatching % and cocoon yield for silkworms treated with both dyes at 100% concentration (T2). Specifically, CSR16 and CSR27 exhibited the highest values for larval weight, cocoon weight, pupation rate and shell ratio % in T2 treatments. The findings suggest that feeding silkworms natural dyes, particularly at higher concentrations, significantly improved the economic parameters of both breeds. While the cocoons produced were intrinsically coloured without compromising commercial parameters, the colour intensity was lighter than anticipated. This implies that introducing dyed mulberry leaves during the 1st instar stage may yield more favourable results. Overall, the study demonstrates that madder and indigo dyes are suitable for producing coloured silk, offering potential for large-scale applications in sustainable silk production.

Rearing Performances of Different Eco-Races of Eri Silkworm (Samia Ricini Boisd.) in Jorhat, Assam

Eri silkworm (Samia ricini Boisd.) is a commercially exploited domesticated silkworm. In the present study an effort was made to evaluate the rearing performances of five eco-races of eri silkworm such as Borduar, Titabar, Dhemaji, Diphu and Kokrajhar in the circumstances of Jorhat district of Assam. The main objective behind this study was to find out the best performing eri silkworm eco-race for the Jorhat district to increase the income of the eri silkworm rearers of the region. To study each of the parameter for evaluating the rearing performances of the eco-races, the larvae were selected randomly from each of the three replication that were maintained separately for the eco-races by using Completely Randomized Design (CRD). The analysis was based on different larval and cocoon characters like larval weight (g), cocoon weight (g), shell weight (g), pupal weight(g), shell ratio (%), effective rate of rearing (ERR%). Out of these five eco-races of eri silkworm Titabar eco-race showed better performance followed by Borduar and Dhemaji in terms of all the aspects. The larval and cocoon parameters were found to be significantly different for each of the eco-race of eri silkworm.

Effects of mulberry leaf enrichment with Lepidium sativum L. seed powder suspension on the economic parameters of Bombyx mori L

The phytochemicals of high nutritional and functional properties in Lepidium sativum L. (garden cress) seeds have nominated their seed powder (regardless of the concentration used) for enrichment of mulberry leaves in order to enhance Bombyx mori L. larval feeding, and consequently to gain ground in sericulture industry. As expected, B. mori larval feeding on L. sativum-enriched mulberry leaves showed not only a remarkable increase in mean values of certain economic parameters of B. mori, such as cocoon weight, cocoon shell weight, pupal weight, and egg yield, compared with the control group, but also showed a phenomenal increase in egg counts (on average, ca. 958–1256 eggs laid per female moth) and a significant increase in egg size (measured as egg surface area and egg volume). Male or female moth larval diet has significantly influenced the reproductive performance or fitness of both sexes of B. mori in terms of large-sized moths (measured as forewing, hind femur, and hind tibia lengths) and highly fecund moths (i.e., increased fecundity and spermatophore counts per female moth, and large-sized eggs). On the basis of B. mori female moth reproductive index, the female moths from L. sativum-fed larvae proved to have a lower reproductive index compared to their corresponding value for females of the control group, indicating more efficient utilization of larval resources for B. mori reproduction. Quantification of the three main physiological resources viz., protein, lipid and carbohydrate in the internal reproductive tract of B. mori female moths at death has nominated the female moth abdomens, or simply their bodies, as being a reasonable natural source of protein, lipid, and carbohydrate, to be involved in certain manufactures (e.g., pet feed formulations) instead of discarding them as a source of environmental pollution. Evidently, the L. sativum seed powder is of considerable interest because it remarkably improves the performance of such an economically important insect, B. mori. This is the first study for evaluating the efficacy of L. sativum seed powder in sericulture field to enhance B. mori productivity parameters.

Enzyme Response in Thermotolerant Silkworm Breeds under Beauveria bassiana Infection

A study on enzyme activity in thermotolerant bivoltine silkworm breeds under Beauveria bassiana disease was conducted at the Department of Sericulture, UAS, GKVK, Bengaluru during 2021-23. Thermotolerant bivoltine breeds viz., B1, B4 and B8, were resistant to muscardine and CSR4, a muscardine susceptible breeds were used in this study. A batch of silkworms of all the breeds were inoculated with 6.86 × 104 spores / ml of B. bassiana @ 0.5 ml per silkworm immediately after 4th moult and another batch were reared under normal condition. The haemolymph was collected from these breeds at 48, 96 and 144 hours post inoculation (hpi) with B. bassiana spores in both inoculated and control batches. Biochemical estimation of amylase, protease and trehalase enzyme activities in the haemolymph. The amylase activity increased from 48 hpi to 144 hpi in all the breeds under both control and muscardine inoculation, but being lesser under inoculation. The protease activity was found higher in B1 breed from 48 hpi to 144 hpi under both control and inoculated conditions. Trehalase activity was enhanced at all time intervals under control conditions in B1, B4 and B8 breeds and CSR4 breed shows decreased at 144 hpi under both control and inoculation conditions. Thus increased enzyme activity in B1 and B4 breeds could be associated with their better performance for survival and economic parameters under inoculated condition. The correlational studies revealed that haemolymph amylase, protease and trehalase were found to be positively corelated with cocoon weight (g) and negatively correlated with larval mortality (%). Thus, the study revealed that silkworm breeds like B1, B4 and B8 as productive breeds and hence may be used for future breeding programmes for evolution of new robust silkworm breeds.

Sublethal effects of nitenpyram on the development of silkworm

The utilization of nitenpyram for aphid and whitefly control may induce environmental contamination and negative repercussions on non-target organisms. Formerly, we found that nitenpyram would pollute the peripheral and sub-peripheral areas of the adjacent mulberry orchard. Under acute toxicity conditions, nitenpyram induced oxidative damage in silkworms, affected biological metabolism, synthesis, immunity, and signal transduction. Considering the impact of nitenpyram mist drift on mulberry leaves, we investigated the effects of low concentrations of nitenpyram on silkworms. The results showed that silkworms exposed to 0.17 mg/L, 0.35 mg/L and 0.70 mg/L of nitenpyram (1/40 LC50, 1/20 LC50 and 1/10 LC50) showed obvious poisoning symptoms. The cocoon weight and cocoon shell weight decreased gradually with increases in the concentration, and these decreases prolonged the growth and development time of silkworms and induced the detoxification enzymes carboxylesterase (CarE) and glutathione-S-transferase (GST) to cope with the stress damage caused by nitenpyram. Exposure to low concentrations of nitenpyram downregulates genes involved in the drug metabolism-other enzymes and peroxisome pathway in silkworms. Additionally, through injection of miRNA mimics and inhibitors, we discovered that detoxifying enzyme pathway genes are influenced by bmo-miR-3382-3P, bmo-miR-3213-5P and bmo-miR-133, regulating the immune response of silkworms. This study provides an overall view of the toxicity and detoxification metabolism of nitenpyram in silkworm, and provides a reference for environmental assessment.

Effect of Phyllanthus niruri on the Escherichia coli Infected Silkworm, Bombyx mori L.

The success of silkworm crop depends on many factors. The good quality mulberry leaf, larval spacing, aeration, protection from disease and pests etc. Many silkworm diseases are caused due to the infection of various bacteria, virus, fungus etc. Diseases such as sotto, flacherie and septicemia are caused due to bacterial infection. In the present investigation, flacherie disease is caused by E. coli. In this study, the leaf extract containing biologically active ingradients from a medicinal plant, Keelanelli (Phyllanthus niruri) was tested for potential in improving the morphology, haemocyte count and economic parameters of silkworm, B. mori. Haemocyte count was significantly increased in the 5µl E. coli inoculated and treated with (6hrs) P. niruri to B. mori larvae. The economic characters of the silkworm viz., shell weight, cocoon weight and shell ratio were also improved by the topical application of plant extract. This study report suggested that the flacherie disease (E. coli) infected silkworm treated with P. niruri plant extract provide significant improvement in cocoon parameters.

Connect the mulberry leaf quality and the silkworm cocoon traits through correlation and regression analysis

An experiment was conducted to study the impact on mulberry leaf quality and silkworm growth performance by the application of growth promoter. In the irrigated mulberry field experiment was carried out in Randomized Block Design layout with four replications and five treatments. Result showed that higher quality of mulberry leaves was obtained on Effective Microorganisms (EM) treated plots compared to others because beneficial microorganism in the EM enhanced the plant growth metabolism to increase their growth. As for correlation analysis, all leaf quality traits were highly significantly positive correlated with silkworm cocoon traits. In simple linear regression analysis, the mulberry leaf quality traits were significantly influenced the silkworm cocoon traits except leaf protein with cocoon weight (Adj R2 = - 0.30337) which has negative relationship between them. Highly close relationship was noticed on total carbohydrate content on larval weight (Adj R2 = 0.93655) followed by total chlorophyll content on shell weight (Adj R2 = 0.90569), silk gland weight (Adj R2 = 0.87275), ERR (Adj R2 = 0.84312) and total carbohydrate content on shell weight (Adj R2 = 0.84606). Thus, the total chlorophyll and carbohydrate content might be a good trait and mostly responsible for producing good quality cocoons.

Effects of florfenicol on the midgut physiological function of Bombyx mori, based on the diversity of intestinal microbiota

AbstractFlorfenicol (FF) is a new antibiotic commonly used in sericulture. This study aimed to examine the effects of low (LC: 0.06 g/L), medium (MC: 0.12 g/L), and high (HC: 1.2 g/L) concentrations of FF on the midgut physiological functions of the silkworm, Bombyx mori (L.) (Lepidoptera: Bombycidae). The results showed that the body weight and the whole cocoon weight of silkworms decreased and the development duration of the fifth instar was prolonged in the HC group. The structure of intestinal microbiota of silkworm larvae was changed by high FF exposure. Specifically, the abundance of conditional pathogens (Curtobacterium, Sanguibater, etc.) was significantly increased, whereas the abundance of Pseudomonas and Pedobacter was decreased significantly. Additionally, the intestinal reactive oxygen species level at 72 h was significantly elevated, and the muscle layer had become loose, together with the appearance of gut goblet cell atrophy. We observed that the increase in Lactobacillus abundance led to a reduction in intestinal fluid pH, resulting in decreased α‐amylase and protease activities, whereas lipase activity exhibited an elevation. The results demonstrated that the accumulation of peroxides induced by exposure to 1.2 g/L FF caused intestinal damage, and the decrease in pH resulting from alterations in microbial composition and structure affected digestive enzyme activity, collectively leading to physiological impairment of the silkworm midgut. These findings provide a valuable reference for the safe use of FF in sericulture.

Selenium Treatment Alleviates the Inhibition Caused by Nep-L Gene Knockdown in Silkworm (Bombyx mori).

Recent studies have emphasized the beneficial effects of 50 μM selenium (Se) on the growth and development of the silkworm, Bombyx mori; however, less is known about its underlying mechanism. To unravel the effect of 50 μM Se on the silkworms with neutral endopeptidase 24.11-like gene (NEP-L) knockdown, we injected small interfering RNA (siRNA) into the body cavity of silkworms. Phenotypic characteristics, mRNA expression of the Nep-L gene, and enriched Se content were evaluated in silkworms from each treatment group. After injecting Nep-L siRNA, the body weight, cocoon quality (cocoon weight, cocoon shell weight, and cocoon shell ratio), and egg production of silkworms were significantly reduced, without any significant effect on egg laying number. However, Se treatment could significantly alleviate the inhibition of body weight, and cocoon quality, without significant effects on egg laying number and production. In addition, the gene knockdown increased Se content in the B. mori. On the molecular level, the targeted Nep-L gene was inhibited significantly by siRNA interference, essentially with the strongest effect at 24 h after RNAi, followed by steady recovery. Among the three fragments, the siRNA of Nep-L-3 was the most effective in interfering with target gene expression. Nep-L gene showed the highest expression in Malpighian tubules (MTs). Both at the phenotypic and genotypic levels, our results show that Nep-L knockdown can exert a significant inhibitory effect on silkworms, and 50 μM Se can reverse the negative effect, which provides a practical prospect for strengthening the silkworm food industry.

Application of Nanotechnology in Sericulture: A Review

Nanoparticles (NPs) have emerged as promising tools for enhancing mulberry cultivation and the performance of silkworms, crucial for silk production. Mulberry, a vital plant for silk production, demands proper nutrient management for optimal growth and leaf production. Application of NPs, particularly zinc oxide and iron oxide, has shown significant improvements in mulberry growth parameters. Furthermore, NPs have demonstrated positive effects on silkworm larvae, enhancing feed efficiency and growth parameters, leading to better cocoon traits. Silkworms fed with NPs-treated mulberry leaves exhibited increased body weight, cocoon weight, and silk filament characteristics. Additionally, NPs have shown promise in enhancing silkworm reproduction and fecundity while conferring resistance against diseases like BmNPV. Various NPs, including TiO2, silver and chitosan, have exhibited antibacterial properties against silkworm pathogens, thereby contributing to disease prevention. Overall, NPs offer a sustainable and effective approach to enhance mulberry cultivation, improve silkworm performance and mitigate disease risks, thus potentially revolutionizing silk production practices.

Effect of Methyl Violet to Mulberry Silkworm Some Breeds Eggs

To liquidate the larvae, the methyl violet (C24H28N3Cl), used against fungal diseases in fish farming, was used. The goal is to establish physiological responses in different phases of development after treating local and introduced mulberry silkworm breeds of with aqueous solutions of methyl violet. Exogenous exposure to eggs led to the formation of a negative reaction. It has been established that treatment of silkworm eggs with water and a 0.001% solution of methyl violet (from October 20 to November 15, 2018) reduces the weight of the silk layer of cocoons with statistical accuracy by 33.0% (−78.5 mg) and 22.5% (−49 .0 mg) respectively (p<0.001). A negative effect also occurs in other physiological indicators: there is a difference in the weight of caterpillars, cocoons and pupae, and a slight deviation occurs in the weight of caterpillars before cocooning in the aquatic version. The results of this research can be used in developing issues such as identifying more stable and promising mulberry silkworm breeds in the conditions of Azerbaijan, as a prerequisite for predicting the successful introduction of mulberry silkworm.

Improvement of Silkworm (Bombyx mori L.) Growth and Cocoon Quality Using Nickel Sulfate Supplementation

The silkworm belongs to the order Lepidoptera and the family Bombycidae (Bombyx mori L.). The silkworm industry plays a crucial role in providing employment opportunities in India. This study investigated the effects of nickel sulfate supplementation on the growth and cocoon quality of silkworm (Bombyx mori L.). The experiment was conducted at a silkworm-rearing center in Palayamkottai, India, from December 2022 to January 2023. Silkworms were fed Victory-1 (V1) mulberry leaves soaked in different nickel sulfate solutions (100 ppm, 300 ppm, and 500 ppm). Larval weight, duration, cocoon weight, shell weight, shell ratio, and pupal weight were measured for 10 healthy silkworms with good quality cocoons selected from each treatment group. Compared to the control group, supplementation with 500-ppm nickel sulfate solution significantly improved silkworm growth performance (weight) and economic traits (cocoon weight and quality). GRAPHICAL ABSTRACT

Traditional vs. Scientific Eri Silkworm Rearing: A Study in Bhubaneswar Zone

Sericulture holds significant importance in the tribal economy of India, with the country being the sole producer of various natural silks including mulberry, tasar, muga, oak tasar and eri silk. Eri silkworm rearing is particularly prevalent in the Bhubaneswar zone of Odisha, encompassing districts such as Khurdha, Jagatsinghpur, Nayagarh, Cuttack and Kendrapada. This study focuses on the traditional eri culture methods in the region, highlighting indigenous rearing techniques, food plant selection, larvae management etc. Observations revealed that traditional practices were consistent across the Bhubaneswar region, emphasizing the need for adopting scientific methods. Implementing tray/platform rearing, precise feeding techniques, strategic food plant selection during different larval stages, well-designed rearing rooms and advanced spinning methods can optimize space usage, ensure disease-free larvae, promote uniform cocoon production, increase the effective rate of rearing and silk production. The disparities in shell percentage between cocoons at the farmer level and the farm level in the Bhubaneswar zone are indicative of varying practices and care in sericulture. Farmer-level cocoons exhibit a lower shell ratio ranging from 9.17% to 9.82%, implying inadequate care and nutrition provided to growing silkworms. This discrepancy suggests that these farmers might face challenges in maintaining suitable conditions such as proper temperature, humidity and nutrition, leading to inferior cocoon quality. Conversely, at the farm level, the shell ratio ranges from 10.14% to 10.71%, indicating that farmers in this category are comparatively more adept at silk rearing practices. They provide better nutrition, suitable temperature, humidity and other necessary facilities, resulting in higher-quality cocoons. The superior environment and care provided at the farm level are reflected in the Effective Rate of Rearing (ERR%) consistently above 40%, reaching a maximum of 50.85%. This signifies that farm-level cocoons have better attributes such as cocoon weight, shell thickness and filament size compared to those reared by individual farmers, where ERR% ranged from 31% to 42%. The integration of modern techniques not only enhances production potential but also creates employment opportunities for rural youth. This approach fosters better income generation, surpassing the limitations of traditional methods and paving the way for a thriving sericulture industry.

Selected Thermotolerant Bivoltine Hybrids of Bombyx mori L. Exhibit Desirable Heterosis for Quantitative Traits under Beauveria bassiana Infection

Four thermotolerant bivoltine silkworm parents viz., B1, B4, B6 and B8 and their 12 hybrids viz., B1×B4, B1×B6, B1×B8, B4×B1, B4×B6, B4×B8, B6×B1, B6×B4, B6×B8, B8×B1, B8×B4 and B8×B6 were used in the experiments. One set of the parents and their hybrids were inoculated with Beauveria bassiana spore suspension (9.04 × 104 spores / ml), on the first day of the fifth instar before first feed and another set were exposed to high temperature (36 ± 1o C temp. & 85 ± 5 % RH) and their responses were studied in terms of heterotic expression of quantitative traits. Significantly highest positive relative heterosis under normal condition was recorded in B1×B4 hybrid for five characters (fifth instar larval weight, cocoon yield by weight, single cocoon weight, shell weight and filament length) and under muscardine inoculation significantly highest positive relative heterosis was recorded in the hybrid B4×B6 for ten characters (ERR, cocoon yield by number, fifth instar larval weight, cocoon yield by weight, single cocoon weight, shell weight, shell ratio, pupal weight, filament length and filament weight). Heterosis scoring over all the traits under muscardine inoculation revealed that the hybrid B4 × B6 scored high overall status of heterotic effects across the characters. Thus, B1 and B8 among parents and B1 × B8 and B4 × B6 among hybrids could be selected for dual stress tolerance against high temperature and muscardine disease.

Field evaluation of multi-viral diseases tolerant bivoltine silkworm hybrid of Bombyx mori l. (Lepidoptera: Bombycidae)

Bombyx mori Densonucleosis virus (BmDV), Bombyx mori Infectious flacherie virus (BmIFV) and Bombyx mori nuclear polyhedrosis virus (BmNPV) infection to silkworms causes major sericulture crop loss. The multi-viral diseases tolerant bivoltine silkworm double hybrid, RDIN1, developed through marker-assisted selection was field evaluated by rearing 20,000 dfls at different location and season. RDIN1, had better pupation (94.8%) compared to control, FC1 X FC2 (91.5%) at farmers’ level with 4 % significant improvement. Average Cocoon yield of RDIN1 (71.2%) was better compared to FC1 X FC2 (69.3%) in unfavourable conditions. Other parameters such as cocoon weight, shell weight, shell percentage, reelability, filament length, raw silk, denier, neatness had also significant difference between RDIN1 and FC1 x FC2. The RDIN1 is expected to reduce cocoon crop losses invariably due to viral infection and fetch more profit to sericulture farmers.

Effect of Spring Goshoerami Mulberry Leaf Extract on Second Commercial Cocoon Crop under Temperate Climatic Condition

Nutrition plays an important role in silkworm rearing. It improves the growth, development, health and feed consumption, thereby improving the commercial traits. As reported, the mulberry leaf under Kashmir climatic condition during Summer/autumn season is nutritionally poor. In Kashmir Valley 90% of silkworm rearers mostly do rearing only once in a year i.e during spring season and lesser number of rearers goes for second rearing during summer/ autumn season because of less productivity and poor quality cocoon crops. Fortification of leaves by supplementing nutrients and using them for feeding the silkworm is a useful technique to increase their economic value. Several attempts have been made to enhance the cocoon yield and silk content through supplement of amino acids on mulberry leaf. However supplement of amino acids on mulberry leaf may not be economical and is not easily assessable to farmers. Silkworm, Bombyx mori L., is a monophagous insect that drives all required nutrients for its growth and development from mulberry leaf. Hence the present study was undertaken to study the efficacy of fortification of spring leaf extract of Goshoerami on growth and commercial traits of double hybrid FC1 (CSR6×CSR26) × FC2 (CSR2×CSR27) of silkworm Bombyx mori L. during second commercial rearing. The results showed, that application of aqueous extract of spring mulberry leaf fed silkworm larvae shows significantly higher in terms of body weight, cocoon weight, shell weight, yield and silk filament length in all the treatments over the control. However the highest body weight (44.143 g/10) mature larval, Single cocoon weight (1.967g), single shell weight (0.471g), shell ratio percentage (23.921 %) and silk filament length (1,159.66 mtr) were recorded at 10% fortification. In order to promote the use of spring leaf extract for fortification among the silkworm rearers further studies are required in consultation with Department of Sericulture of the U T of Jammu and Kashmir.

Enhancing natural enemy performance through plant secondary metabolites: The role of caffeine for the parasitoid Snellenius manilae

AbstractThe food resources in the field can effectively strengthen the ability of natural enemies to control the pest. Certain compounds, in addition to carbohydrates and amino acids, may improve the physiological performance of insects. Caffeine, for instance, has been shown to enhance pollinator memory and physiological reactions. However, little is known about how caffeine influences parasitoids. The control effectiveness and survival rate of the parasitoid (Snellenius manilae) were tested in this study after the parasitoids were fed solutions with different concentrations of caffeine. We examined caffeine concentrations of 10−2, 10−4, and 10−6 (M) mixed with a 25% sucrose solution and a pure sucrose solution as a control group. The results show that a concentration of 10−6 caffeine solution significantly increased the parasitism rate of S. manilae by 10.76% when compared to the control group. Despite the significantly lower survival rate and male bias of S. manilae offspring in the 10−2 treatment, no further negative responses in growth performance, development time, or cocoon weight were observed. These findings suggest that an appropriate concentration of caffeine solution can have a positive impact on the control effectiveness of parasitoids in the laboratory. Our results highlight the potential of secondary compounds to increase the bio‐control effectiveness. However, confirming the implications of these findings requires further field experiments.

A Comparative Study of Drying of Muga Cocoons using Convection and Infra-red Heating Method

Background: Muga is an exclusive golden-colored silk produced by the Antheraea Assamensis silkworm species in North-east India. In the silk processing stage, drying of Muga silkworm cocoon is essential to prevent the pupa from emerging from the shell and to preserve the cocoons for a longer period (3-6 months). It is necessary to reduce the potentially harmful high moisture level in the cocoon shell and pupa body to an optimum or safe level of moisture content (6-12%). In India, the natural sun drying method is the most common method to preserve Muga cocoons for a longer period. Considerably losses may occur using the sun-drying method due to various effects such as rodents, insects, rain, microorganisms, excessive temperature, etc. To address this issue the study was conducted to improve the quality of Muga silk yield using a comparative study between Convection and IR heating methods for cocoon drying. Methods: In this study, Muga cocoons were dried properly at optimum temperature (50-100°C) to obtain a safe moisture level for getting quality Muga silk. The drying of the Muga cocoon is processed using convection (1 kw) and Infrared (650 watts) modes of heating for the same duration of time. Muga cocoons were placed in a drying chamber initially at a high temperature (100±5°C) using both convection and Infrared heating methods separately to maintain the moisture content to an optimum level. It took approximately 75 minutes to obtain the temperature 100 from room temperature and every 15 minutes temperature measure was recorded for both methods and compared. The parameters studied were temperature, time, cocoon weight, shell weight, shell ratio and moisture content. These parameters were examined, evaluated and compared for both the Convection and IR heating methods. Result: The comparative study results indicated that the performance of the studied cocoon parameters namely temperature, cocoon weight, shell weight, shell ratio and moisture content are approximately similar for both convection and IR heating methods. Moisture content was maintained at the optimum range (6-12%) for both the convection and IR methods. The study provided a better performance using the IR heating method as compared to convection heating concerning energy consumption and safety for the same duration of time. Energy consumed by a 1 kW convection heater is 1.25 kWh, whereas energy consumption in a 650-watt IR heater is 0.8125 kWh.