• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.1
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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.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.130-137
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• 1996

Effect of topical application with 5, 10 and 15${\mu}$g/ml thyroxine on the pre-cocoon, cocoon, postcocoon and silk improvement were studied in bivoltine silkworm NB18 breed of B. mori L. Thyroxine was applied independently on alternate days to silkworm of IV and V instar larvae. The treatment of all different concentrations resulted in a significant increase in commercial characters like larval weight, silkgland weight, cocooning percentage, female cocoon weight and its shell weight and male cocoon shell weight and its ratio, cocoon dimension, length of the filament and its weight and oviposition. However, there was no significant change in larvel weight in 5${\mu}$g/ml treated group and larval duration was significantly decrease. But moth emergence percentage and hatching percentage did not show any significant change when compared with that of carrier control.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.191-195
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• 2003

The impact of antibiotic (Norfloxacin) administration ,at different concentration (50 ppm and 100 ppm) on commercial characters of bivoltine $({CSR_2}{\times}{CR_4})$ and the cross breed race $({BL_67}{\times}{CSR_101})$ was studied. The result indicated that antibiotic administration with different concentrations significantly improved the rearing and cocoon parameters like larval duration, larval weight, growth index, single cocoon weight, single shell weight and shell ratio. The post cocoon parameters like average filament length, non-breakable filament length, raw silk percentage, raw silk recovery percentage, denier, reelability and neatness were recorded significantly higher in antibiotic treated batches. The better performances of these parameters were recorded with the increase of antibiotic concentration.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.2
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• pp.149-153
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• 2002

Induction of non-diapause eggs and manifestation of quantitative characters were studied in different seasons by low temperature incubation of eggs of a low yielding diapause with coloured cocoons silkworm breed, RDI of Bombyx mori. Hundred percent of nandiapause eggs were induced when the egg incubation was carried out at 15$^{\circ}C$ followed by incubation initially at $25^{\circ}C$ and then at $15^{\circ}C$. The diapause-nondia-pause relation was found to be reversible. Analysis of variance study demonstrated significant variation in all the quantitative characters whereas significant variation due to different incubation treatments was observed for larval span, fifth instar larval span, cocoon yield/10,000 larvae by weight, cocoon weight, cocoon shell weight, and cocoon shell ratio. study on hybrid vigour skewed significant heterosis over mid parent value for four economic characters viz., cocoon weight, cocoon shell weight, cocoon shell ratio and filament length in a Fl hybrid between RD1 with diapause eggs and Japanese type bivoltine $NB_{4} D_{2}$.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.27-32
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• 2004

With an objective of evolving quantitatively and qualitatively superior bivolitine silkworm hybrid of Bombyxmori L. for tropics with shorter larval duration without compromising on productivity traits, a breeding programme was initiated at this institute during 1997 by utilizing breeding resource material from the institutes Germplasm collection. The breed SD7 is characterized with plain larvae spinning white oval cocoons and SD12 is characterized by sex-limited larval markings spinning white dumb-bell cocoons. After fixation, these breeds along with other newly evolved breeds were subjected for hybrid evaluation in the laboratory. Based on the hybrid studies, the hybrid SD7${\times}$SD12 was selected and evaluated for one year comprising three major sea- sons (6 trials) of tropics viz., Pre-monsoon (characterized by high temperature, low humidity and without any rain fall), Monsoon (characterized by moderate temperature, heavy rain fall with high humidity) and post-monsoon season (characterized by low temperature and low humidity with frequent rain fall) to know the fluctuations in the larval duration. The evaluation studies indicated that the hybrid is having shorter larval duration with productive merits. The hybrid SD7${\times}$SD12 recorded survival percent of 92.74, shell weight of 46.7 cg, shell ratio % of 24.0 and filament length of 1,200 meters with a shorter larval duration of 24 hrs; when compared to productive hybrid CSR2${\times}$CSR5(control). The breeding methodologies and hybrids usefulness for tropics were discussed.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.555-562
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• 2022

We raised the white-spotted flower chafer, Protaetia brevitarsis seulensis, from the larvae stage using a fermented mulberry sawdust-base diet at 25℃ and 16:8 h light:dark photoperiod. First, we determined the optimal density of the neonate larvae to be introduced into a rearing box (543 × 363 × 188 mm). The survival rates of the larvae were higher than 80% at 90 days after rearing at 100-175 larval densities but reduced by more than 10% at 200 larval density. The larval weights at 100 to 150 larval densities were similar; however, the weights at 175 and 200 larval densities were lower than those at 100 larval densities, indicating that the rate of weight gain increased under lower density. Based on these results, we inferred that 100-150 larvae was the optimal density. Second, we investigated the storage conditions of the last instar larvae under low temperatures. Four weight groups (1.8-2.0, 2.0-2.3, 2.3-2.5, and 2.5 g) of larvae were stored at 4, 8, and 10℃, respectively. All the larvae at 4℃ died 70 days after storage, whereas 80% of the larvae survived at 8℃ 70 days after storage, indicating that high larval weight was associated with high survival rates. The adults that emerged from larvae with more than 2.3 g and stored for up to 50 days at 4℃ laid few eggs. However, the adults that emerged from all larval weight groups stored for 70 days at 8℃ and 10℃ laid several eggs successfully. Based on these results, we inferred that the last instar larvae with more than 2.3 g could be stored for 30-50 days at 8℃.

• Journal of Ecology and Environment
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• v.44 no.1
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• pp.45-53
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• 2020

Background: The black soldier fly (Hermetia illucens) is gaining attention as an efficient decomposer of food waste. However, recalcitrant compounds such as plastics mixed into food waste may have negative effects on its growth and survival. Moreover, its efficiency of food waste degradation may also be affected by plastics. In addition, salt (NaCl) can also be present in high concentrations, which also reduces the efficiency of H. illucens-mediated food waste treatment. In this study, we assessed the growth of black soldier fly larvae (BSFL) reared on food waste containing polyethylene (PE) and polystyrene (PS) and NaCl. The weight of BSFL was measured every 2-4 days. Survival and substrate reduction rates and pupation ratio were determined at the end of the experiment. Results: The total larval weight of Hermetia illucens reared on food waste containing PS was greater than that of the control on days 20 and 24. However, the survival rate was lower in the group treated with 5% PS, as was substrate reduction in all PS-treated groups. The weight of BSFL reared on food waste containing PE was lower than that of the control on day 6. PE in food waste did not affect the survival rate, but the pupation ratio increased and substrate consumption decreased with increasing PE concentrations. Regardless of the plastic type, the addition of NaCl resulted in decreased larval weight and pupation ratio. Conclusions: Larval growth of black soldier fly was inhibited not by plastics but by substrate salinity. Additional safety assessments of larvae reared on food waste containing impurities are needed to enable wider application of BSFL in vermicomposting.

• Journal of Environmental Science International
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• v.29 no.9
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• pp.939-941
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• 2020

This study evaluated the effect of four different feeds on the larval weight and survival rate of Protaetia brevitarsis seulensis (PBS) over five weeks. Four different types of feed (self-fermentation medium, RM medium, Samsung livestock medium, and bean-curd dregs medium) were given to third-instar larvae of PBS. Weight changes and survival rates of PBS larvae were measured weekly for five weeks. During the experimental period PBS larvae showed the highest growth in Samsung livestock medium, followed by bean-curd dregs medium, RM medium, and self-fermentation medium. Survival rate of PBS larvae were the lowest in bean-curd dregs medium, and then in the Samsung livestock medium. Using the Samsung livestock medium can shorten the delivery period of PBS larvae by approximately 40 days based on the larva shipped on average 75 days. Therefore, this study provides information and data on insect farming techniques useful for insect industrialization.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.1
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• pp.7-14
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• 2006

A breeding programme was initiated during 2001 to introduce sex-limited larval markings to a productive multivoltine breed - BL67 from an inbred sex-limited line, MY1 (SL) maintained at Central Sericultural Research and Training Institute, Mysore. Introgressive hybridization, recurrent backcrossing for six generations followed by sib-mating resulted in synthesis of a new multivoltine silkworm breed BL67 (SL) with sex-limited larval markings. The new breed was studied for combining ability by crossing with eight bivoltine breeds viz., $NB_4D_2,\;CSR_2,\;CSR_2 (SL),\;CSR_2,\;CSR_4,\;CSR_8,\;CSR_{18}\;and\;CSR_{19}$. General combining ability effects of the new breed showed its superiority over the popular Pure Mysore by expressing significant GCA effects for six out of twelve characters whereas the results are on par with the original multivoltine breed. The hybrid $BL67(SL){\times}CSR2(SL)$ excelled in several quantitative characters such as pupation rate (90.2%), cocoon weight (1.97 g), cocoon shell weight (40 cg), cocoon shell ratio (20.3%), filament length (918 m), denier (2.96), raw silk percentage (14.96%) and neatness (90 p). Studies on cocoon size variability revealed that the cocoons of $BL67(SL){\times}CSR2(SL)$ were found comparatively uniform showing less standard deviation of 6.55 and co-efficient of variation of 3.91 %. The suitability of newly developed breed for easy grain age operation and commercial exploitation with promising hybrid have been discussed.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.114-120
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• 1995

The effect of juvenile hormone analogue(JHA, Manina) on larval feeding duration, pupation ratio, cocoon weight, and cocoon shell weight in the present commercial parent and hybrid silkworm stocks were investigated. Topical applications of JHA on parent silkworm stocks were to prolong larval duration, but results of response on those stocks were not consistent. Especially the JHA on Jam 121, Jam 123 and Jam 138 did not play a role in larval duration, whereas that on Jam 114 was most effective in prolongation more than two days, compared with the controls. subsequent prolongation of feeding duration resulted in increase of cocoon weight and cocoon shell weight of most parent silkworm stocks, while Jam 114 showed decrease in cocoon weight and cocoon shell weight in spite of prolonged feeding duration of two days. Unlike the parent silkworm stocks, durations of feeding period in all hybrid silkworm stocks were prolonged about one day. Treatments of JHA on the hybrid stocks gave rise to increase of cocoon weight and cocoon shell weight, and especially were most effective in Sasung-jam, Eunbaek-jam and Samgwang-jam. Although treatments of JHA seemed to have no harmful effect on physiology of parent silkworm stocks as well as that of hybrid stocks, the JHA retarded pupation ratio of some parent silkworm stocks such as Jam 122, 131, 135 and 138 by about 10%.