• International Journal of Industrial Entomology and Biomaterials
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• 제14권1호
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• pp.1-7
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• 2007

In order to find out the appropriate parents for the breeding programme, twelve bivoltine and three multivoltine silkworm breeds were evaluated on the basis of multivariate selection index and isozyme analysis. Of which, four [CSR2, D6 (P), SK3, SK4] bivoltine and two multivoltine (Nistari, Cambodge) breeds were selected and breeding initiated to develop higher survival bivoltine silkworm breed suitable for tropical conditions. Among two isozyme (Esterase and acid phosphatase) analyzed, only esterase exhibited polymorphism among the bivoltine breeds. No polymorphism was observed among multivoltine in respect of esterase as well as acid phosphatase.

• International Journal of Industrial Entomology and Biomaterials
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• 제20권2호
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• pp.61-67
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• 2010

The bivoltine tropical tasar ecoraces of Antheraea mylitta Drury produces cocoons for seed production under seed crop rearing (July-August with $22{\sim}30^{\circ}C$ temperature and 50~70% relative humidity) and for silk production under commercial crop rearing (September-December with $17{\sim}27^{\circ}C$ temperature and 60~80% relative humidity). To consider the impact of hybrid vigour on egg, larva, cocoon and silk related commercial traits, the $F_1$ hybrids made among Daba, Jata and Raily ecoraces were assessed successively for three years. The hybrid vigour in the $F_1$ hybrid of Daba$\times$Jata ($T_7$) was positive for egg fertility (+23.1%), shell weight (+25.6%), silk yield (+79.0%) and filament length (+68.1%), with filament of high denier (11.98d) and reduced larval span (-7.1%). The Jata$\times$Daba ($T_8$) hybrid has shown negative heterosis in egg fertility (-8.0%) compared to the other F1 hybrids, Daba$\times$Raily ($T_9$) and Raily$\times$Daba ($T_{10}$), when they rise simultaneously during the commercial crop season. The better performance of parental ecoraces ($T_4$ to $T_6$) in their commercial traits during commercial crop over parents of seed crop ($T_1$ to $T_3$) and the superior performance of $F_1$ hybrids ($T_7$ to $T_{10}$) over parents of commercial crop ($T_4$ to $T_6$) during commercial crop season indicates the apparent hybrid vigour in tasar $F_1$ hybrids. As the Daba$\times$Jata ($T_7$) and Jata$\times$Daba ($T_8$) $F_1$ hybrids have shown highest hybrid vigour, their rearing during commercial crop can optimize the silk productivity and commercial sustenance of the tasar silk industry.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권2호
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• pp.83-91
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• 2002

The protection of silkworm and its host plants from various kinds of pests parasite and predator is a chronic problem in sericulture. Silkworms and its primary food plants are heavily damaged by large number of pest. The major pests of primary tasar food plants (Terminalia arjuna and Terminalia tomentosa) are the gall insect (Trioza fletcheri minor). Various species of aphids (Eutrichosiphum sp.) have been recorded to damage oak tasar food plants whereas muga silkworm host plants (Machilus bombycina and Litsaea polyantha) are generally attacked by stem bores (Zeuzera multistrigata). Castor (Ricinus communis) is one of the primary host plant of eri silkworm and extensive damage is caused by the castor white fly (Trialeurodes ricini). Insects pests are major enemies of silkworms. Parasites (Blepharipa zebina, Exorista bombycis, Apateles glomeratus), predators (Canthecona furcellata, Sycanus collaris, Hierodulla bipapilla), wasps (Vespa orientalix) and ants (Oecophylla smargdina) continues to cause damage to silk industry. It is estimated that the losses due to parasites and predators are to an extent of 15-20 percent and varies from crop to crop. The complexities in the behaviour and life cycle of pest population existing in semi ecosystem warrant a special attention for their effective management specially in changing scenario for our modern sericulture. Though use of synthetic insecticides has provided us with effective control of almost all major pests and predators, yet their undesirable side effects limit their continued use. Biological control is one of the most important method which can be used to control the pests, parasites and predators population in sericulture. Various potential parasitoids, which can be utilized as an agent of biological control in sericulture have been screened. The natural enemies of the uzi fly (E. bombycis and B. zebina ) are already present in the nature. Nesolynx thymus, Trichria sp., Splangia endius, Dirhinus sp., Trichopria sp., Trichomalopsis apanteloctena and Pediobius sp. are the major parasitoids effective against uzi fly pupa. The scelionid Psix striaticeps and Trissolcus sp. are the Potential egg Parasitoids against stink bug (Canthecona furcellata). Various other native natural potential parasitoids have been screened and suitable strategies have been developed to check the population of pest insect in sericulture.

• International Journal of Industrial Entomology and Biomaterials
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• 제18권2호
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• pp.77-82
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• 2009

The egg shell of the tropical tasar silkworm, Antheraea mylitta is formed from the substances secreted by the follicular epithelium during the late vitellogenic stage. TEM study reveals the inner travecular and outer lamellar layer of chorion. The travecular layer is composed of the innermost wax layer, inner and outer chorionic layer. The inner and outer chorionic layers are connected to each other by vertical pillers forming of cavities. The lamellar layer is perforated by the aeropyles. SEM study reveals the differentiation of an anterior surface of the egg shell into four zones-micropylar, edge, aeropyles crown and disc zone. In the mycosis infected eggs the aeropyles and egg-shell surface are fully packed with the hyphae of the fungus, Aspergillus sydowi blocking of plastron respiration and causing the death of developing embryo so that mycosis infected eggs become sterile.

• International Journal of Industrial Entomology and Biomaterials
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• 제20권2호
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• pp.37-43
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• 2010

The wild silkworm, Antheraea mylitta Drury (Lepidoptera: Saturniidae) is a polyphagous silk producing insect that feeds on Terminalia arjuna, T. tomentosa and Shorea robusta and is distributed in the forest belts in different states of India. Phenotypically distinct populations of the A. mylitta are called "eco-race" or "ecotypes". Genetic improvement of this wild silkworm has not progressed much due to lack of adequate information on the factors that control the expression of most of the economically important traits. Considering the amazing technological advances taking place in molecular biology, it is envisaged that it is now possible to take greater control on these intractable traits if a combination of genetic, molecular and bioinformatics tools are used. Linkage disequilibrium (LD) mapping is one such approach that has extensively been used in both animal and plant system to identify quantitative trait loci (QTLs) for a number of economically important traits. LD mapping has a number of advantages over conventional biparental linkage mapping. Therefore, LD mapping is considered more efficient for gene discovery to meet the challenge of connecting sequence diversity with heritable phenotypic differences. However, care must be taken to avoid detection of spurious associations which may occur due to population structure and variety interrelationships. In this review, we discuss how LD mapping is suitable for the dissection of complex traits in wild silkworms (Antheraea mylitta).

• International Journal of Industrial Entomology and Biomaterials
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• 제19권1호
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• pp.143-154
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• 2009

Single nucleotide polymorphisms (SNPs) are the most frequent form of variation in the genome of any organism. Owing to their greater abundance, they are considered useful for identifying cultivars, construction of higher density linkage maps, and detection of genes (QTLs) associated with complex agronomic traits and diseases. Although, SNPs have been used recently for constructing a high density genetic map in silkworm and a set of 118 SNPs have been identified in tasar silkworms, not much progress has been made in sericulture to utilize the vast potential of SNPs. Thus, this review mainly focuses on some of the important methods of SNP discovery, validation and genotyping. Emphasis has also been given to the possible uses of SNP genotyping in the improvement of silkworms and their host plants.

• International Journal of Industrial Entomology and Biomaterials
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• 제17권1호
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• pp.109-113
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• 2008

Realizing the scope of utilizing by-products of silk cocoons by applying appropriate methods is the immediate crave to optimize returns. The nutritive value of pupae suits for human diet, feed for poultry, carps, fish, rabbits, piggery and dogs. The pupal skin, fat, oil, cocoon palade have applications in oleo chemical, soap, glycerin, cosmetic, artificial fibres, membranes and n-triacontanol isolation. The pupal proteins Chitin, Shinki fibroin, Serrapeptidase, glucosamine are latent precursors of post surgical, anti-carcinogenic, anti-inflammative, anti-bacterial, anti-histaminic, gastric, hepatitis, pancreatitis, leukocytopenia, neurological, ophthalmic, blood pressure, cardiac and diabetic medicines and for preparation of vitamins A, E and K. The silk and its proteins sericin and fibroin are potentially used for wound healing, diabetes, impotence, sinusitis, arthritis, edema, cystitis, epididymitis, tissue regeneration, cancer, post-surgical trauma and used as anti-oxidatives, bio-adhesives, ultra violet screens and bio-active textiles. The waste cocoons can be used in making art crafts like garlands, carpets, overcoats, decoratives and greeting cards. The in-depth research towards utility optimization and make aware this reality to sericulturists, reelers, weavers, traders, entrepreneurs, policy makers etc., is the upright want of the today's Sericulture industry.

• International Journal of Industrial Entomology and Biomaterials
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• 제10권1호
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• pp.19-24
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• 2005

Nutrition is very essential for growth, development and reproduction. The quantitative impetus of nutritional factor on adult characters and reproductive fitness was studied in Antheraea mylitta by providing fresh leaves of Terminalia tomentosa for 1 to 4 times a day to $5^{th}$ instar larvae. All the characters have improved on giving fresh diet more times over the single diet. The adult weight has strong effect on the reproductive potential i.e., female pupa and moth weight, survivability, pupation rate, emergence percentage, fecundity, fertility, egg weight and hatched out larval weight. The improvement recorded to the tune of $70\%,\;77.1\%,\;115.4\%,\;36.7\%,\;45.9\%\;and\;218.3\%$ in larval weight gain, survivability, pupation rate, female pupa weight, moth weight and fecundity respectively when fresh diets were provided 4 times a day against single diet. The adult emergence percentage has increased from $66.4\%\;to\;96.2\%$ and fertility rose from $52.2\%\;to\;93.6\%$. The weight of eggs and the larvae hatched out of it also found to be significantly higher in 4 diets a day condition. The study revealed that optimization of fresh diet frequency should be maintained to obtain higher egg production and fertility in order to get vigorous larvae to continue the generation.

• International Journal of Industrial Entomology and Biomaterials
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• 제27권2호
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• pp.243-264
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• 2013

Antheraea mylitta Drury is a commercial silk producing forest insect in India and Xanthopimpla pedator Fabricius is its larval-pupal endoparasitoid, which causes pupal mortality that affects seed production. Effects of host plants, rearing season and their interactions on parasitic behaviour of X. pedator were studied here, as influence of these factors on biological success of X. pedator is not known. Seven forest tree species were tested as food plants for A. mylitta, and rate of pupal parasitization in both the rearing seasons were recorded and analysed. Results showed that rearing season and host plants significantly affected the rate of pupal parasitization in both the sexes. Pupal mortality was found significantly higher (14.52%) in second rearing season than the first (2.89%). Likewise, host plants and rearing seasons significantly affected length, diameter, and shell thickness of cocoons in both sexes. Out of all infested pupae, 85.59% were found male, which indicated that X. pedator chooses male spinning larva of A. mylitta for oviposition, but we could not answer satisfactorily the why and how aspect of this sex specific parasitic behaviour of X. pedator. Multiple regression analysis indicated that length and shell thickness of male cocoons are potential predictors for pupal parasitization rate of X. pedator. Based on highest cocoon productivity and lowest pupal mortality, Terminalia alata, T. tomentosa, and T. arjuna were found to be the most suitable host plants for forest based commercial rearing of A. mylitta in tropical forest areas of Uttarakhand state, where it has never been reared earlier. Sex and season specific interaction of X. pedator with its larval-pupal host, A. mylitta is a novel entomological study to find out explanations for some of the unresolved research questions on parasitic behaviour of X. predator that opens a new area for specialised study on male specific parasitization in Ichneumonidae.

• International Journal of Industrial Entomology and Biomaterials
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• 제27권1호
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• pp.166-179
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• 2013

In India, forest based insect enterprises has never been linked up with any forest management activity, either as a forest conservation strategy or to reduce the poverty in forested area. This investigation indicated that when forest dependent people are associated with forest insect industry (FII) like forest sericulture, lac culture or apiculture; this income generating activity links livelihood with forest conservation, and generates a viable model of collaborative forest management (CFM). In this model different stakeholders work together as a coherent entity for unified goal of managing the forest for well-being of the poor people in fringe areas. Article summaries and evaluates the prospect of India specific forest insect industry, and discusses how and to what extent integration of FII could be a viable livelihood component in CFM to conserve the forest and insect biodiversity. We analysed a case study on forestbased rearing of tropical tasar silkworm rearing in Central India from CFM perspective. Arguments in this communication are intended to provide forest managers and policy-makers with necessary input to consider location specific FII in CFM mode to provide a continuous source of small income to forest dependent people to ensure long lasting success of their forest management endeavours.