• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.103-109
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• 2000

To evolve silkworm hybrids with higher survival and better cocoon characters, evaluation of semen hybrids in the laboratory (short-listed out of 143 hybrids) resulted in the identification of two promising hybrids, A3${\tines}$935 E (HSP1) and A3${\tines}$916 B (HSP2). The hybrids were evaluated at three different Regional Sericultural Research Stations of Central Silk Board during 1997-1998 and also tested with the farmers along with two control hybrids, KAxNB4D2 and PMxNB4D2. Evaluation of the hybrids indicated that these hybrids can be reared in all the seasons, especially during summer season. These hybrids show shorter larval duration (22 days 17 hrs against 23 days in control KAxNB4D2 and better cocoon characters as compared to the crossed breeds PM ${\tines}$NB4D2).

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.11-14
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• 2003

Systemic fungicides viz., Bavistin and Beyleton are reported to have curative effect against the infection of Beauveria bassiana in silkworm Bombyx mori L. To understand the influence of the systemic fungicides on the disease suppression/development, hematological studies were carried out. There was an increase in the percent total hemocyte count, granulocyte and plasmatocyte in silkworm treated with the systemic fungicides. It possibly indicates the influence of systemic fungicide on the hemocyte mediated defense system leading to the higher resistance and suppression of disease development.

• International Journal of Industrial Entomology and Biomaterials
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• v.25 no.2
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• pp.147-151
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• 2012

Fifteen races resulted from silkworm breeding program at Sericulture Research Department (SRD) were used for hybridization. Fourteen hybrids were obtained and coded as; Giza C, D, R, S, T, U, A, V, W, P, H, L and Qanater 1, 2. The traits of cocoon weight, cocoon shell weight, pupal weight, cocoon shell ratio, silk productivity, fifth instar duration, total larval duration, number of cocoon per liter and pupation ratio were evaluated. Data were analyzed by using three formulae of heterosis over better, mid and check parent values. Hybrids of Giza V, C, N, Qanater 1 and 2 are promising and could be used in commercial cocoon production. Generally, there are some new hybrids can be exploited in commercial scale. Also, the local races can be evolved using the hybridization, inbreeding and selection program.

• Journal of Sericultural and Entomological Science
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• v.41 no.2
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• pp.94-101
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• 1999

Twelve pure silkworm lines identified based in higher G.C.A values from a line${\times}$Tecter crossing programme, were crossed with twelve breeds showing cocoon shell ratio>22% and hybrids prepared, evaluated in a Multiple index method. Seven hydrids showing average index value>50 in all the 10 economic characters were seclcted and evaluated in the laboratory. However, two hybrids viz., A3${\times}$935E and A3${\times}$916B were finally selected based on the superiority of the breeds in one day shorter larval duration and with and with higher reeling characters compared to control KA${\times}$NB4D2. The breeding procedure involed in evolution hybrids are discussed.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.37-43
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• 2002

Eighteen new bivoltine silkworm (Bombyx mori L.) hybrids developed at Andhra Pradesh State Sericul-ture Research and Development Institute, Hindupur are evaluated for 10 economic traits by following two multiple trait index methods, i.e., Subordinate Function and Evaluation Index for their economic merit. The hybrid genotype, APS6${\times}$APS11 with highest Subordinate function value of 8.2432 and highest average Evaluation Index of 61.67 ranked first. This hybrid is adjudicated as most promising hybrid and recommended for commercial use. Further, applicability of Subordinate Function Index Method is tested and recommended for application of multiple trait evaluation similar to Evaluation Index Method as the results obtained are comparable. Further, both these methods can be applied for confirmation of results.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.2
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• pp.107-111
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• 2005

Impact of microsporidian infection and season on reproductive potential of Bombyx mori L. was investigated in the laboratory. Microsporidian infection significantly (P<0.01) reduced fecundity and hatching and increased sterility and mortality of eggs. Among the microsporidia, Nosema sp. 2 infected silkworm produced eggs with least fecundity and hatching percent as well as highest dead and sterile eggs followed by Nosema sp. 1 and N. bombycis. Microsporidia, in general, significantly reduced fecundity and hatching percent of eggs and increased number of dead and sterile eggs in all the three seasons except N. bombycis in July - August (S3) and Nosema sp. 2 in January February (S1). Since, seed production is the anchor sheet of mulberry sericulture, coefficient of egg lying is considered as an important aspect and the industry quite often facing shortage of disease free layings. The present study indicates that B. mori is more susceptible to microsporidia during S2 followed by S3 and S1 and Nosema sp2. is most virulent followed by Nosema spl. and N. bombycis.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.1
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• pp.49-55
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• 2005

Two BC1 group, c108 $\times$ (p50 $\times$ c108) and p50 $\times$ (p50 $\times$ c108), one group of F$_{2}$ progeny, (p50 $\times$ c108) F$_{2}$ ,and 3 SSR markers, F10539, FlO626 and FlO618 were used to test the hereditary properties of SSR markers in silkworm. FI0539, FlO626 were proved to be linkage, and FlO618 was proved to be independent to those two markers. According to Mendel's law, the recombinant value between F10539, FlO626 was calculated in all of these groups, and they were 8.55$\%$ (c108BC1), 8.02$\%$ (p50BC1) and 7.81 $\%$ (F$_{2}$) respectively. There was dominant difference among the crossing-over value using paired-samples tests by SPSS 10.0 software. This research proved that SSR markers were co-dominant in B. mori too, and F 2 progeny could be used to construct SSR linkage map although B. mori lacked of crossing over in females.

• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.186-188
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• 1994

• Journal of Sericultural and Entomological Science
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• v.17 no.2
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• pp.125-132
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• 1975

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.155-159
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• 2000

In the spring silkworm rearing period of year 1998, some nutritional aspects were studied in the Agricultural Research Station of the Komotini town in Greece, to investigate the feeding behaviour of some Bulgarian silkworm hybrids, suitable for spring rearing, during the fourth and fifth instal under the local climatic conditions. The silkworms were fed by locally cultivated Japanese Kinriu mulberry (Morus alba L.) variety leaves. Eight Bulgarian hybrids had been used, namely Vratza-53xVratza-52, Ukraine-20xVratza-53, Super 1xHessa 2, Merefa 2xVratza 35, as well as their reciprocal crosses. The studies showed out a remarkably higher feed intake and feed utilization by the hybrids Hessa 2xSuper-1, Merefa 2xVratza 35 and Vratza-52xVratza-53. The same hybrids showed an efficient food utilization by means of daily growths cocoon shell ratio and raw silk output. In terms of food to silk conversion efficiency Hessa 2xSuper-1 hybrid gave the best results. Larval stage duration for fourth and fifth instar was not affected by feed intake and utilization. All hybrids showed a good adaptation to the local environment and their feeding performance was equal to the international existing standards. All calculated parameters were found to be around the mean values of other up to date presented results and thus considered as acceptable for the needs of the local production.