• International Journal of Industrial Entomology and Biomaterials
• /
• v.7 no.2
• /
• pp.203-208
• /
• 2003

Rearing temperature influences food consumption, conversion and cocoon production in silkworm Bombyx mori L. Young age $({1^st}to{3^rd} instar)$ worms of Pure Mysore, a multivoltine were reared at 26, 28, 30 and $32^{\circ}C$ followed by combinations of these temperature levels during late age $({4^th} and {5^th} instar)$. Food consumption, conversion, larval duration and growth for each instar were recorded. The influence of combinations of these temperature levels during rearing on survival and cocoon production was assessed. Food consumption increased with the temperature up to $4^th$ instar and decreased during $5^th$ instar. Temperature beyond $28^{\circ}C$ during young age followed by higher temperature ($30^{\circ}C$ and above) has shown deleterious effect on cocoon production. The paper discusses the rearing performance in relation to food intake and conversion under the tested temperature levels.

• Journal of Sericultural and Entomological Science
• /
• v.42 no.1
• /
• pp.10-13
• /
• 2000

The objective of this research was to characterize of the silkworm that might be recognized to the Korean native strains. The eleven strains of Korean race used in this study, which is cultured in Korea and Japan seri-cultural research organs. Most of Korean varieties were three molting and univoltine, comparatively longer larval duration than the trimolter general. The egg characters of varieties showed short-eliptic shape and dark brown egg color except for a few varieties which shows greenish dark brown. Also, most of varieties were showed the plain(p) and moricaud( $p_{M}$) in larval markings. Moric marking of the varieties also consist of innumerable dark grayish brown lines and dots, though somewhat darker and lighter than that of the wild silkworm, Bombyx mandarina. Cocoon characters variations of varieties were seen in the size, color and shape. 8 varieties were colored cocoon, i.e., yellow, greenish yellow and light green etc., the others were white cocon. The shape of cocons were consisted of constricted shallowly in the middle and attenuated at one or both ends of cocoon, i.e., spindle. The results of this study is sufficient evidence that Korean strains were shown as the one of regional origin strain of domesticated silkworm such as the Chinese and Japanese etc.c.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.14 no.1
• /
• pp.45-50
• /
• 2007

Ethanol extract of 20 botanicals in 3 concentrations i.e., 2.5%, 5% and 10% were evaluated for their efficacy to improve reproductive performance of mulberry silkworm (Bombyx mod L.) through feeding botanical enriched mulberry leaves during $2^{nd}$ day of $4^{th}$ age as well as $1^{st}$ and $3^{rd}$ day of $5^{th}$ age larvae. The preliminary screening was done by ranking the botanicals based on influence in most important reproductive contributing parameters such as single cocoon weight, effective rate of rearing, pupation rate, fecundity and recovery of eggs/kg cocoon. Five botanicals viz., Asparagus recemosus, Achyranthes aspera, Tribulus terrestris, Withania somnifera, Parthenium histerophorus ranked first were further evaluated at 8% 5% and 3% concentrations to confirm their effectiveness and standardize effective concentration. Among the rearing parameters, mature larval weight, shell ratio and number of cocoons/kg were not significantly influenced by the treatments. However, reproductive parameters such as effective rate of rearing (wt), pupation rate (%), fecundity (No.) and egg recovery (g)/kg cocoon were significantly (P<0.05) influenced by the botanicals. Higher fecundity and egg recovery were obtained on treatment with Withania somnifera irrespective of concentrations. However at 5% concentration, pupation rate, fecundity as well as egg recovery were found significantly higher than that of other concentrations, confirming its effectiveness for improving reproductive efficiency.

• Journal of Sericultural and Entomological Science
• /
• v.35 no.2
• /
• pp.105-113
• /
• 1993

To produce F1 hybrid of silkworm sex discrimination has to be followed at the pupal stage by sexual organ. However it requires a lot of labour and may bring about a wrong classification. In these regards, this study has been implemented to find out an effective measure for the pupal sex discrimination by use of variation of cocoon weight and image analysis of cocoon. As a result, it was found that in case of the pupal weight the percentage of a wrong classification fell on 0.3% and in case of single cocoon weight 0.4%. The discrimination rate was 99% in the weight variables of cocoon but analysis by single cocoon weight and cocoon shape variables, it was 98.7%. Efficiency of discrimination was increased by 2.7% as compared to variable of single cocoon weight. The minimum cocoon sampling size may be 15 cocoons sexual-wise.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.8 no.1
• /
• pp.107-112
• /
• 2004

The combining abilities in the 5 newly evolved thermo tolerant breeds viz., SR6, SR7, SR8 SR9 and SR10 of silkworm Bombyx mori L. and their 15 hybrids were made in a line${\times}$tester crossing programme. Data were analysed for seven quantitative traits i.e., pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio, filament length and raw silk percentage under optimum room temperature $(25{\pm}{1^{\circ}C})$ conditions (In case of high temperature $(36{\pm}{1^{\circ}C})$ stress conditions five economic traits except filament length and raw silk percentage) with 3 widely adapted testers i.e., KA, CSR2 and CC1 as lines (females) and testers (males) respectively. The performance at high temperature and low humidity conditions aye only taken into consideration for selecting the best lines/hybrids. Among the lines SR6 exhibited positive General combining ability (GCA) effects for pupation rate, cocoon yield, cocoon weight and cocoon shell ratio traits, followed by SR7 for pupation rate, cocoon yield and cocoon shell weight and cocoon shell ratio. Among testers, KA exhibited positive GCA effects for two quantitative traits cocoon yield, cocoon weight and CSR2 for cocoon shell weight and cocoon shell ratio under adverse temperature conditions. The hybrid SR6${\times}$CC1 and SR7${\times}$CSR2 exhibited significant positive Specific combining ability (SCA) effects for majority of the traits in high temperature stress conditions of rearing. The better parent value of heterosis(Heterobeltiosis) was exhibited by the hybrid SR6${\times}$CC1 for pupation rate, cocoon yield, cocoon weight and cocoon shell weight and SR7${\times}$CSR2 for all the trails evaluated under high temperature conditions. Based on the results, the lines SR6 and SR7 was judged as best combiners and the hybrids SR6${\times}$CC1 and SR7${\times}$CSR2 can be selected for commercial exploitation in tropical climate.

• Journal of Sericultural and Entomological Science
• /
• v.16 no.2
• /
• pp.141-146
• /
• 1974

This study was carried out to observe the possibility of special rearing of young silkworm for a simple cooperative rearing in the indoor vinyl house. The results of this study are as follows. 1. Temperature and humidity were regulated reasonably in the indoor vinyl house in comparison with general rearing and covered rearing with damp-proof and all workings in it were more convenient. 2. Duration of silkworm life was same in the covered rearing with damp-proof and indoor vinyl house, but general rearing was longer spring rearing silkworm period, 5 hours and autumn young silkworm period. 6 hours than indoor vinyl house. 3. In the mortality ratio, missing larvae of general rearing was more than any other treatments in spring and autumn. There was no difference between covered rearing with damp-proof and indoor vinyl house rearing, but missing larvae seemed to be a little indoor vinyl house. 4. In the individual cocoon ratio there was no significance in spring and autumn, but best cocoon ratio was high in the special rearing and good and low cocoon ratio was high in the general rearing. 5. In the cocoon weight of 10,000 3rd moulted silkworm. cocoon weight of general rearing was less than any other treatments in spring rearing season, and that of covered rearing with damp-proof and indoor vinyl house rearing It was same result. 6. There was no significance in the cocoon layer ratio in spring and autumn, but that of covered rearing with damp-proof and indoor vinyl house was high in comparison with general rearing. 7. As showed above, it is considered that the rearing of indoor vinyl house is worth as special rearing of young silkworm for simple cooperative rearing because it showed good records with three times feedings a day in comparison with general rearing and covered rearing with damp-proof.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.2 no.1
• /
• pp.65-68
• /
• 2001

A new silkworm variety, Chunsujam, for spring rearing season is F$_1$ hybrid between Japanese race Jam145 bred by 8459/8711 and Chinese race Jam146 by 8544/M8626. Jam145, Japanese parent of the Chunsujam, showed high GCA in pupation rate and Jam146, Chinese parent, showed high GCA in pupation rate and single cocoon weight. In the local adaptability test performed at 8 local areas in spring of 1999, Chunsujam was 5% higher in larval weight, 3% in single cocoon weight, and 4% in cocoon yield from 10,000 of the 3rd molted larvae, respectively, than the check variety Baegokjam.

• Journal of Sericultural and Entomological Science
• /
• v.55 no.1
• /
• pp.6-10
• /
• 2019

Current status and prospect of sericultural industry in Gyeonsangbukdo were examined through history and business of institute, sericultural status of Gyeongsangbukdo, purchasing results, and prospects of Gyeongsangbukdo. Silkworm & Insect Business Center was established in 1911 as Sericultural training institute. Original silkworm 400 case, and Nuedongchunghacho inoculant 100 box will be spreaded. Sericultural farmer is 339 and 41.5 percent on the whole country in 2016. Ten thousand kilogram of cocoon was purchased by institute in 2016. Farm income was increased to 13.7 million won and purchased cocoon 9,875 kg in 2017. To activate sericulture Gyeongsangbukdo will support Hanbok Institute in 2019 and make sericultural complex.

• Journal of Sericultural and Entomological Science
• /
• v.17 no.1
• /
• pp.41-46
• /
• 1975

In order to investigate the individual difference in the cocoon quality of female and male silkworm, Bombyx mori, the individual variation of cocoon quality of all the examined population, the variation of cocoon quality within batches. The variation of batches were also examined with 19 batches (843 cocoons of female and 806 of male) of lam 111 X Jam 112, and the daily variation of cocoon quality after harvesting on 300 good cocoons of female and male is as follows：(table omitted) 2. The daily variation of cocoon quality after harvesting. The daily reduction rate of cocoon weight after havesting was higher at the late stage than at the beginning stage of pupal duration and it showed a tendency to be higher in male than in female pupae.

• Journal of Sericultural and Entomological Science
• /
• v.18 no.2
• /
• pp.95-100
• /
• 1976

Utilization of the various cocoon beds were evaluated by raising the silkworm variety "Seul-ak${\times}$Soyang"according to cocoon quality produced in spring of 1969: Rotary cocoon bed, improved cocoon bed, grima cocoon bed, wood framed straw rope cocoon bed, and pine cocoon bed. In addition the economical analysis was made on the basis of cocoon price in spring of 1976. 1. The Rotary cocoon bed has economically much advantages in many ways; easy cocoon collection and percentage of best cocoon, percentage of cocoon shell, reelability and percentage of raw silk. It may give 8100 won for an extra income per box and increase by raising higher yielding variety. 2. The grima cocoon bed is superior to the wood framed straw rope cocoon bed, and the pine cocoon bed and it is comparatively easy set-up even though it is inferior to the improved cocoon bed in many characters.