• International Journal of Industrial Entomology and Biomaterials
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• 제30권2호
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• pp.31-39
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• 2015

Antheraea mylitta Drury (Lepidoptera: Saturniidae) is a commercial silk producing forest insect of India, but it has never been experimented in Uttarakhand state in spite of the huge availability of its forestry host plants. This is the first study on A. mylitta in Uttarakhand. The goal of this study is to introduce forest based commercial rearing of A. mylitta, in tropical forest areas of Uttarakhand to reduce poverty among forest dependent people. In current study, we assessed the effect of seven forest tree species, rearing seasons, and their interactions on cocoon productivity of Daba (bivoltine) ecorace of A. mylitta in the New Forest of FRI, Dehra Dun during 2012 and 2013 and collected the data that was analysed by two-way completely randomized block factorial design. Post HOC Tukey's HSD test was carried out to compare the homogeneous pairs of means. We also carried out Evaluation Index analysis to rank the tested forestry host plants for better growth and development of A. mylitta under the climatic condition of Uttarakhand. Analysis of variance indicated that cocoon yield of A. mylitta differed significantly between rearing seasons (DF=1, F=88.24, p<0.05) and host plants (DF 6, F= 368.63, p<0.05); however, their interactions were found insignificant (DF=6, F=0.99, p>0.05). In first rearing season of July-August, there was higher cocoon yield than the second season of September-November. Results indicated that Terminalia alata fed larvae showed significantly higher cocoon yield (164.11 cocoons/300 larvae); followed by, T. tomentosa (148.89 cocoons), T. arjuna (140.00 cocoons) and Lagerstroemia speciosa (129.47 cocoons) fed larvae. Whereas, Lagerstroemia tomentosa fed larvae that was used by the first time in India, showed lowest cocoon yield (48.81 cocoons), followed by T. chebula (72.53 cocoons) fed larvae. Cocoon yield of T. tomentosa and T. arjuna fed larvae of A. mylitta did not differ significantly with each other.

• International Journal of Industrial Entomology and Biomaterials
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• 제32권1호
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• pp.1-11
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• 2016

Tropical tasar silkworm, Antheraea mylitta is a commercial forest silkworm in India that produces tasar silk, but never experimented in Uttarakhand, a Himalayan state of India. A. mylitta express divergent phenotypic characters under different ecological conditions; so, we studied the effect of seven forest tree species in two rearing seasons on variability in silk gland weight of Daba (bivoltine) ecorace of A. mylitta at Forest Research Institute in Dehra Dun, Uttarakhand during 2012 and 2013. We used two-way completely randomized block factorial design and Post HOC Tukey's HSD test to analyse the collected data and there after carried out multiple regression analysis. Results indicated that silk gland weight differed significantly between rearing seasons (DF=1, F=2333.98, p <0.05), host plants (DF 6, F= 1516.25, p <0.05) and their interactions (DF=6, F=7.10, p <0.05). Higher silk gland weight was found in second rearing season than the first on all the host tree species. Terminalia alata fed A. mylitta larvae showed the highest silk gland weight of 8.03 and 9.47 g in first and second rearing seasons, followed by T. tomentosa (7.19 & 9.01g), T. arjuna (6.8 & 8.08 g) and L. speciosa (6.57 & 7.83 g) fed larvae, respectively. Post HOC Tukey's HSD test indicated that silk gland weight of L. speciosa and T. arjuna fed larvae in both the rearing seasons did not differ significantly. E.I. analysis also confirmed that T. alata, T. tomentosa, T. arjuna and L. speciosa are better in their order of merit than T. bellirica , T. chebula and L. tomentosa. Multiple regression analysis indicates that larval weight gain is a strong predictor (β=1.002, t=346.777, p = <0.05) for the silk gland weight of A. mylitta ; however, larval duration had significant negative regression weight (β=-0.270, t=-8.436, p = <0.05) on mean weight of silk gland.

• 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.