• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.1
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• pp.93-119
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• 2014

Tropical tasar silkworm, Antheraea mylitta (Lepidoptera: Saturniidae) is a polyphagous silk producing forest silkworm of commercial importance in India. Forest dependent people rear its larvae on different forestry host plants twice or thrice in a year for small household income. Larvae of A. mylitta feeds on many forest tree species, but always show a great degree of selectivity as a function of its behavioural responses to physical structure and chemical features of the host plants. Cocoon crop of A. mylitta is influenced by heterogeneity of tasar food plants and climatic conditions of the habitat. The role of host plants, temperature, humidity, rainfall, photoperiod and climatic variables on the growth and development of insects have clearly been demonstrated. This article entails an in-depth analysis on ecological and nutritional aspects of A. mylitta, which may provide selective information to researcher and forest managers, who are particularly associated with livelihood improvement of the poor people in forested area through location specific forest insect industry.

• International Journal of Industrial Entomology and Biomaterials
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• v.43 no.2
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• pp.99-103
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• 2021

In the present study, twelve bivoltine silkworm races were evaluated for its performance based on quantitative and qualitative traits. Seven oval and five peanut cocoon shaped races were reared in different seasons of the year. By using evaluation index method, the results showed that six races were identified as potential parental races. Among oval races, 75xin, KoC, KoZ and among peanut races An 902, 7532 and QD7 were selected as base material. The identified high yielding races will be used in various breeding programs as initial parents for the production of superior bivoltine breeds/hybrids in Vietnam

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.2
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• pp.74-80
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• 2013

Three new Multi ${\times}$ Bi combinations M.Con.4 ${\times}$ (SK6 ${\times}$ SK7), M.Con.4 ${\times}$ NB4D2 and Nistari ${\times}$ (SK6 ${\times}$ SK7) were studied in five seasons i.e. during the period of $18^{th}$ June - $12^{th}$ July, $30^{th}$ August - $23^{rd}$ September, $3^{rd}$ November - $2^{nd}$ December, $29^{th}$ January- $2^{nd}$ March and $30^{th}$ March-$25^{th}$ April with one control Nistari ${\times}$ NB4D2 considering nine reeling characteristics along with shell percent and cocoon yield per 100 disease free layings (DFLs) to establish the seasonal effect on all the parameters. Results reveal that all the characters performed well in November-December. Highest yield per 100 DFLs was recorded during November-December in all combinations showing >60 kg yield. Higher correlation of yield/100 DFLs with filament length, non-breakable filament length, denier, raw silk percent, reelability percent and recovery percent was recorded in all combinations of Multi ${\times}$ Bi considered in this study. Variability observed among four combinations indicates the effect of different temperature and humidity of different seasons on expression of different traits. The results indicate that there is significant relationship of raw silk percent with reelability percent, recovery percent and evenness. Reelability percent showed higher correlation with recovery percent. It was observed that neatness was positively correlated with evenness. The overall performance of the newly evolved combinations with regard to productivity and reeling characteristics is discussed emphasizing their utilization at commercial level.

• Journal of Sericultural and Entomological Science
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• v.52 no.2
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• pp.117-122
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• 2014

On previous studies, we constructed a transgenic silkworm which produces the chimeric silk fused green fluorescent protein (EGFP), but the transgenic silkworm has decreased commercial feasible traits such as convenience of breeding and productivity of silk. In this study, we performed cross fertilization between green fluorescent silk transgenic silkworm and colored cocoon silkworm descents to make the transgenic the transgenic silkworm producing improved fluorescence cocoon. In the result, we found out a bit valuable cross fertilization manners ($female{\times}male$) in respect of silk productivity such as $T59B{\times}Jam26$, $Jam329{\times}T59W$, $T59W{\times}Jam329$, and $T59W{\times}Jam178$. The color-difference of offspring cocoons were measured according to different cross manners using by CIE Lab-based formulae with a X-rite VS450. In the result, the depth of green color of cocoons was a little high at cross manners as $Jam329{\times}T59W$, $T59W{\times}Jam178$. Meanwhile, the depth of yellow clolor of cocoons was remarkable at cross manners as $Jam178{\times}T59W$, $T59W{\times}Jam178$, respectively.

• International Journal of Industrial Entomology and Biomaterials
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• v.20 no.2
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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.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.124-129
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• 1996

Oral application of dimethyl sulfoxide in different concentration (1, 3 and 5 percent) to silkworm, Bomyx mori at the fourth and the fifth instar has significantly increased the commercial characters such as larval and silkgland weights, female and male cocoon weights, their shell weights and egg production. However, larval duration, cocooning and hatching percentages did not showed any significant change, as compared with that of the corresponding parameters of the carrier control. Similarly the glycogen and protein contents of the fat body and trehalose and protein contents of the haemolymph were significantly increased in 1 and 3 percent, whereas the increase of them in 5 percent concentration did not take place significantly, except haemolymph trehalose where it was found to be significant, as compared with that of carrier control.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.118-123
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• 1996

Dietary supplementation of folic acid to silkworm larvae in different concentration (100, 200 and 300 ${\mu}$g/ml) to the 4th and the 5th instar resulted in a significant increase in economic parameters, such as female and male cocoon weights, shell weights, egg productivity and egg hatching percentage. However, larval duration was significantly decreased, as compared with that of carrier control. The increase in the glycogen and protein contents of the fat body was not significant, whereas the increase in trehalose content of haemolymph in all the treated groups and protein content of fat body and haemolymph in 100 ${\mu}$g/ml treated groups were significant. However, the haemolymph protein was significantly decreased in 300${\mu}$g/ml treated group.

• Journal of Sericultural and Entomological Science
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• v.53 no.1
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• pp.12-18
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• 2015

This study was conducted to consider practical use of F2 hybrid and intervariety crossing for the improvement of silkworm eggs export and silkworm eggs manufacture. Now Kumokjam and Baegokjam come into wide use to sericulture farmers but comparison test of F1, F2 hybrid and intervariety have not been done. We weighed against the productivity among economical character. While larval period of F2 among them is most long time, pupation percentage and cocoon yield per 10,000 3rd molted larvae are lower than intervariety. With comparing F2 and intervariety, single cocoon weight of F2 is lower 9 ~ 21% than intervariety, and cocoon shell weight of F2 was lower 10 ~ 18% than intervariety. By number of cocoons per liter, F2 hybrid was lower and more irregular size than intervariety. In coparison with number of egg laid, F2 hybrid Baegokjam was 655 ea (14%) and Kumokjam 625 ea (40%) more than F1 hybrid. Also, F2 hybrid for filament grade went down than F1 hybrid. The advantage of egg production in F2 hybrid can reduce costs because there is no necessity for sex discrimination and germination control. But besides increase of number of egg laid, the productivity including economical characters was greatly lowered. Except for being a lot of laying eggs, cocoon productivity of the F2 was greatly reduced by degeneration of practical traits. Therefore the further studies are needed in order to increase utilization value of the F2 hybrid silkworm.

• International Journal of Industrial Entomology and Biomaterials
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• v.19 no.2
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• pp.249-253
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• 2009

Raily ecorace of Indian tasar silkworm is wild in nature and distributed abundantly in dense deciduous forest on Shorea robusta (Sal) in Bastar ($17^{\circ}4'$ and $20^{\circ}34'$ N, $80^{\circ}15'$ and $82^{\circ}15'$ E and altitude ranging from 150 to 1200 mMSL) forest ranges of Chhattisgarh, India. It is represented by about 20 populations. Out of those, eleven populations showed intra- as well as inter- population variability based on phenotypic expression and also in major economic traits viz. cocoon weight, shell weight, filament length and denier. Genetic diversity in these eleven populations was studied using Inter-Simple Sequence Repeat (ISSR) markers. The band profiles generated with eight ISSR primers have depicted variation in band size. All the primers exhibited polymorphism which is an indicative of the genetic variation in individual Raily silkworm. Among the populations, total polymorphism recorded was 76%. The population genetic aspects assessed through POPGENE software package are discussed in the paper. Nei's gene diversity (h) ranged from 0.194 to 0.337 exhibiting high heterozygosity. Relevance of the present study is of high significance in formulating conservation strategies and sustainable utilization of the economically important Raily ecorace of Antheraea mylitta.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.147-151
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• 2005

Serious attempt for the improvement of quality parameters in silkworm hybrids came rather very late in India. Realising the need for productive breeds to the field and reorientation in breeding methodology, the silkworm breeders of CSRTI, Mysore were able to develop silkworm breeds with fine denier namely, JPN7, CSR48, B63 and B65 of specific industrial requirement through directional selection. As the success of silkworm breeds mainly depends on their combining ability, the developed breeds were subjected for hybrid evaluation. Out of 42 bivoltine hybrids studied, one hybrid, $CSR48{\times}CSR5$ was identified for its superiority over the existing bivoltine hybrids namely $CSR2{\times}CSR4,\;CSR2{\times}CSR5\;and\;CSR18{\times}CSR19$ for majority of qualitative traits. Post cocoon testing of large quantity of cocoons of $CSR48{\times}CSR5$ resulted in the production of high quality '3A'grade silk. It is for the first time in the Indian Sericulture industry that high quality silk with longer filament length of 1474 m, denier of 2.47, standard size deviation of 0.983 d, maximum size deviation of 1.322, neatness of 96 p, reelability of $85\%$, tenacity of 3.87 g/d, elongation of $22.32\%$ and cohesion of 110 strokes was produced. The superiority of fine denier silkworm breeds and their hybrids are discussed.