• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.79-83
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• 2002

The wild silkmoth, Actias gnoma was firstly collected at Suwon located in the middle part of Korea. The developmental and morphological characteristics of A. gnoma reared under the laboratory conditions were analysed. The egg shape was shorter elliptic. The major and minor diameter of the eggs were 2.04 mm and 1.83 mm, respectively. White mucous material was remained inside the eggs after hatching. Also, the body color of the larvae was completely changed from dark brown to light yellowish-green at the 3rd instar, but it did not occur until pupation. In the feeding test on several plants, the oak tree, Quercus acutissima, was newly identified as a host plant. The final larval instar was mostly 6th, but in some larvae it was 7th. A few of larvae ate their own casts just after ecdysis. The whole larval duration ranged from 45 to 59 days. The single cocoon weight, cocoon shell weight and cocoon shell percentage were 1.65 g,31.3 cg and 18.9%, respectively, The cocoon shape and color were spindle and light brown, respectively. The morphology of the silk gland was greatly different from those of Bombyx mori, Antheraea yamamai and Antheraea peryi: the thickness of the middle and posterior silk glands was almost identical.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.77-81
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• 2002

A new non-cocooning silkworm variety, Hachojam, suitable for autumn rearing season is single cross Fl hybrid between Japanese race Jam 307 and Chinese race Jam 126. Jam 307, Japanese parent of the Hachojam, which is a source for non-cocooning process showed a high GCA (generation combining ability) in naked pupation rate and Jam 126, Chinese parent, showed a high GCA in pupation rate and single pupal weight. In the local adaptability test performed at 8 local areas in autumn of 1999 to 2000, the naked pupation rate and thin cocoon rate of Hachojam were 64.7% and 35.3% , respectively. The pupal weight calculated from 10,000 of the 3rd molted larvae was 24% heavier in Hachcjam than the cocoon-producing, check variety Daesungjam.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.2
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• pp.157-162
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• 2001

The effect of topical application with naphthoxyacetic acid on economic parameters was analyzed following treatment of fifth instar larvae. Larvae treated during the fifth instar showed significant increase in larval weight along with other enhanced larval, cocoon and adult parameters. The larval period was significantly shortened in all the treated groups with increased cocoon and shell weights in male and shell weight in female in 400 ${\mu}g$/ml treated group and filament length in all the treated groups. Fecundity increased significantly in dose dependent manner in all the treated groups, when compared to that of the carrier control group. This suggests that naphthoxyacetic acid, in addition to affecting larval growth, also affect silk production and reproductive performance.

• Korean Journal of Environmental Agriculture
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• v.14 no.1
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• pp.82-87
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• 1995

The standardization of test procedures and reproducibility of the toxicity data are prerequisite for the toxicity testing with the earthworm culturing in the laboratory. No in-depth study on culturing conditions of earthworms has been conducted in Korea, even of massive cultural practice is common for composting and production of biochemicals. The earthworms, Lumbricus rubellus and Eisenia foetida, were cultured in three kinds of artificial soil substrates(I, II and III) based on the OECD Guideline, which consist of different ratios of components (sand, sphagnum peat and kaolinite), and fed with a mixture of grain powders. During the period of culturing, the body weight and reproduction parameters were measured. L. rubellus showed the best results for increasing body weight and cocoon production in the artificial soil substrate(I) compared with E. foetida. The cocoon production was significantly high in both species cultured in the artificial soil substrate(I) among the three kinds of soil substrates, but the cumulative cocoon production of L. rubellus was 11 cocoon per worm compared with 3.7 cocoons per worm of E.foetida. L. rubellus, therefore, was more prolific than E. foetida in these culture schemes. The cumulative mortality in both species was less than 10%, and the number of juvenile worms per cocoon ranged from 1.5 to 2.3 and thus did not show any relationships with soil substrates or species. From these data, the culture of L. rubellus in the laboratory could be standardized, but for E. foetida, further study would be necessary to establish the optimal growth conditions in the laboratory.

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

• Journal of Sericultural and Entomological Science
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• v.31 no.2
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• pp.102-112
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• 1989

Principal component analysis and cluster analysis were performed on the nine quantitative characters of the one hundred and forty eight silkworm genetic stocks. The six major quantitative characters such as cocoon yield, cocoon weight, cocoon shell weight, cocoon shell percentage, larval period of the 5th instar silkworm, and total larval period showed significantly positive correlation between them. The first three principal components extracted form the initial nine variables by principal component analysis accounted for about eighty percent of original information. The first and second principal components were characterized as factors related to silk productivity, and cocoon productivity, respectively. On the basis of multivariate analysis using city block distance determined from the first three principal components to measure the phenotypic diversity, the one hundred and forty eight silkworm genetic stocks could be clustered into seven varietal groups, and the phenotypic diversity between the varietal groups was partly related to their geographical origins. Among 7 varietal group, group II and IV revealed higher silk and cocoon productivity.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.47-51
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• 2004

To evolve silkworm hybrids with higher survival and productivity and easy and effective seed cocoon production, three new evolved bivoltine hybrids of silkworm (Bombyx mori L.), created with participation of sex-limited lines at eggs and larva stage were evaluated with control Super$_1$${\times}$Hessa$_2$ hybrid at Plovdiv Agrarian University during 2000 - 2002. ANOVA analysis was employed and the performance of hybrids was observed in respect of main quantitative traits. The results obtained show significant superiority of new hybrids T$_{15}$ 4/${\times}$TBV$_{2}$24/, XT$_{215}$38/${\times}$TV$_{3}$2/, XT$_{215}$38/${\times}$B$_{2}$6/ and their reciprocal crosses over the control. They were characterized with 99% hatchability of eggs, 93-95% silkworm survival, 2.32- 2.42 g cocoon weight, 53.5-55.7 cg shell weight, 22.9-23.1% shell ratio, 1,307-1,326 m filament length, 3.08-3.17 denier, 95-96% reelability, 44.4-45.1% silk ratio, 569-593 number of normal eggs per lying and 347-364 mg weight of normal eggs per lying. Newly evolved hybrids were manifested high productivity, 41.0-43.6 kg cocoon yield and 7.33-7.78 kg raw silk yield per one box (20,000$\pm$200 viable eggs), which significant surpass the control Super$_1$${\times}$Hessa$_2$ hybrid with 7.6-14.4% and 10.8-17.6%, respectively. T$_{15}$ 4/${\times}$TBV$_{2}$24/ and XT$_{215}$38/${\times}$TV$_{3}$2/ were considered as highly productive hybrids to local conditions and found suitable to rear in spring season.n.

• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.37-42
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• 1986

The experiment was carried out to investigate the effects of juvenile hormone analogue on changes of protein and amino acids in haemolymph of silkworm larva. Juvenile hormone analogue was topically administered to larvae at dose of 1$\mu\textrm{g}$ 10$\mu\textrm{g}$ per gm of body weight at 60hr. of the 5th instar. The results obtained were as follows ; 1. Larval duration of the fifth instar was extended about 1 day by JHA-1 and 4 days by JHA-10 as compared with the control. 2. Cocoon weight and cocoon layer weight by topical application of JHA were heavier than those of the control, but cocoon layer ratio was decreased in JHA-10 to the exclusion of JHA-1. 3. The concentration of haemolymph protein during the fifth instar was increased remarkably by the JHA application. 4. The total content of amino acids in haemolymph proteins of JHA-10 approximately doubled that of the control, with the conspicuous increase of glycine and arginine level.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.311-316
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• 2009

The study was conducted to evaluate the effects of dietary acid hydrolysates of cocoon on laying performance, egg quality, blood level of immune substance and cholesterol in laying hens. The animals used in the experiment were a total of 240 Hy-Line Brown laying hens (41 weeks old). Dietary treatments included 1) CON (basal diet), 2) SP1 (basal diet + acid hydrolysates of cocoon 0.05%), 3) SP2 (basal diet + acid hydrolysates of cocoon 0.1%) and 4) SP3(basal diet + acid hydrolysates of cocoon 0.2%) twelve laying hens were allotted to a block (pen) with five replicated. Through the whole period of experiment, egg production, egg weight, egg shell breaking strength and egg shell thickness were no significant difference. However, acid hydrolysates of cocoon treatments (SP1, SP2, SP3) significantly increase their egg yolk height and Haugh unit compared to control (P<0.05). IgG and WBC (white blood cell) contents in blood were higher in SP1, SP2, SP3 treatment compared to control (P<0.05). However, albumin and total protein content in blood were no significant difference. Phospholipid, HDL-cholesterol, LDL-cholesterol and total cholesterol contents in serum were higher in SP1, SP2, SP3 treatment compared to control (P<0.05). In conclusion, supplement dietary acid hydrolysates of cocoon improved egg yolk height, Haugh unit, and blood level of phospholipid, HDL-cholesterol, LDL-cholesterol, total cholesterol in laying hen.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.26-31
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• 1978

The objective of the present study was to investigate the effect of nicotine-contaminated mulberry-leaf, which was grown in the vicinity of tobacco drying plant (TDP), on cocoon crop. Mulberry-leaf harvested from the field at Sericultural Experiment Station (SES), Suweon, Korea, was used as control, supposedly nicotine-free leaf. Leaf harvested from the field in the distances of 30-50m, 300-400m and 700-800m from TDP was fed during the whole larval stage of the silkworm at. SES. The effect of leaf in each treatment level on the quantitative characters of the silkworm was summarized as follows; 1. Larval duration from 4th instar on was significantly longer in the TDP-leaf treatments than for the control. 2. Duration of matured silkworm appearance became longer as the distance of the mulberry-field from TDP got shorter, because the larval duration and growth of the silkworm were not uniform in the TDP-leaf treatments. 3. Mortality rates during the late larval, cocoon spinning, and pupal stages were highest for the 30-50m leaf, especially mortality rates during the late larval and pupal stage were serious. 4. Pupation rate was lowest for the 30-50m leaf and those for the 300-400m and the 700-800m leaf were not significantly different from that of the control. 5. Nicotine damage to cocoon weight and cocoon shell weight was significant in each TDP-leaf level. Cocoon shell ratio was reduced at the same extent in each level, compared with the control. 6. The ratio among cocoon-classes was significantly different between treatments, compared with best-cocoon ratio of 87.1% for the control. Cocoons were not uniform for the 30-50m leaf, and those for the 300-400m and the 700-800m leaf were as almost uniform as those for the control. 7. Loss of fresh cocoon yield became greater as the distance of the mulberry-field from the TDP-got shorter. In conclusion, the critical distance of mulberry-field, which influences larval health, cocoon quality and yield, appeared to be 800m from the TDP. Such other factors as wind direction and topographic location may be involved in the critical distance. 8. From the present experiment, we could obtain only the effect of nicotine on the silkworm through digestive system, since the silkworm was raised at SES in Suweon. If the silkworm.. were raised in the vicinity of the TDP, poison effect of nicotine on the silkworm could beo expected through exoskeleton and tracheal system as well as through digestive system.