• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.1
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• pp.128-134
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• 2014

Nesolynx thymus Girault (Hymenoptera: Eulophidae) is one among 20 hymenopteran parasitoids reported to attack the uzi fly, Exorista bombycis, which in turn infests the silkworm, Bombyx mori accounting a cocoon yield loss of 10-20%. A host of factors viz., age and size of host, age and size of parasitoid, availability of host, temperature and quality of host are reported to influence the reproductive efficiency of the parasitoids. In the present study an attempt was made to record the influence of foraging parasitoid density on their reproductive performance. Three day-old uzi pupae were offered to varying numbers (1 - 10) of 2 day old Nesolynx thymus adults for parasitization. The progeny production per pupa (84.44 - 132.77) increased significantly with increase in the number of foraging parasitoid adults (1 - 10) however, progeny production per female decreased. The sex ratio (M : F) (1:25.49 - 1:1.53) decreased significantly with increase in foraging parasitoid adults. The morphometric parameters except female abdomen width of first generation parasitoid showed significant negative correlation with number of foraging adults. However, correlation between the parasitoid size in first generation and their reproductive performance was nonsignificant.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.1
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• pp.1-4
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• 2011

This study was conducted to test the use of colored cocoon silkworm, Golden Silk, as a host for the fruiting body production of Cordyceps mushroom. Golden Silk variety had a shorter larval period than Yangwonjam at $25.3^{\circ}C$ and 78.5% RH: The average larval period of the Golden Silk was 24 days and 7 hr, and that of the Yangwonjam was 24 days and 15 hr. In the infection test of I. tenuipes on silkworm, the larval period of normal silkworms was longer than the silkworms inoculated with I. tenuipes in both Golden Silk and Yangwonjam. The pupae survival percentage of Golden Silk was 94.4%, whereas it was 91.9% in Yangwonjam. Golden Silk had a higher pupation rate than Yangwonjam. The pupation rate of normal silkworms was about 5% higher than that of silkworms inoculated with I. tenuipes. Infection rate of I. tenuipes into larvae of 5th instar newly exuviated silkworm was 93.8% in Golden Silk, and 96.9% in Yangwonjam. Synnemata production of I. tenuipes was better in Yangwonjam with an incidence rate of 99.8% than Golden Silk with 98.6%. The average synnemata weight of Golden Silk was 1.12 g and that of Yangwonjam 1.29 g. Golden Silk had a lower synnemata weight than Yangwonjam. But no significant difference was observed in synnemata weight varieties. The synnemata of I. tenuipes produced on pupae were white or milky-white in color, and similar in shape and color to wild synnemata collected in Korea.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.321-330
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• 1999

Nematodes were isolated using silkwom trap through the investigation of 100 soil samples from various biotopes in Korea. The 30 nematode strains from soil and dead insects by the pathogenicity aganinst silkworms (Bombyx mori mori) and insect pests of Calliphora vomitoria, Pseufazetia separata, Palomena angulosa, and Melolontha incana. Mortailty of the silkworm larvae and pupae were as high as 100% by nematode infection, those of insect of pests were varied from 20 to 100%. The 30 strains of entemopathogenic nematodes were classified into five groups of Rhabditidae, Diplogatroidae, Heterorhabitidae, Steinernematidae, and Tylenchida by morphological criteria. The genetic relationships among the 30 nematode strains were analyzed by various RAPD bands with twenty primers. The 30 nematode strains were classified into six major subgroups on the basis of the genetic similarity coefficient of 0.853. The grouping by RAPD was agree with those of morphological taxa in discrimination of the higher group, however, was not completely agree in the subgroup. The family Steinernematidae belong to Rhabditida was clarified as closer to the Tylenchida, rather than the other Rhabditida of Heterorhabitidae, Rhabditidae, and Diplogatroidae in genetic distance valule. From the result of the morphological classification and RAPD of the genomic DNA showed that genetic relationship analysis furnish infurmation on phylogenetic classification and relationships of entomopathogenic nematodes. The application of genetic similarity will overcome the limitation of taxonomy and classification of morphologically simple nematode. Several primers were confirmed those utility of identification for individual nematode strains, the methods of molecular genetics secured the simplicity, rapidity and accuracy on the selection of entomopathogenic nematodes.

• Journal of Sericultural and Entomological Science
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• v.26 no.1
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• pp.35-51
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• 1984

In order to know the similarity of the electrophoretic protein patterns, distributional aspects of the frequency in each protein band, differences of protein patterns between female and male, and the number of the total protein bands of each variety in the haemolymph of the silkworm pupae according to their geographical origin, the silkworm varieties, and both the sexes, variable electrophoretic protein patterns were observed by polyacrylamide gel electrophoresis, using the silkworm strains which have been reared in the sericultural experiment station. 1. The total number of electrophoretic protein bands classified were twenty-eight, and nearly fourteen bands were shown by each variety on an average. 2. According to their geographical origin, the mean values of the similarity were 20.0%, 28.3% and 14.3% in Japanese, Chinese and European respectively, and the highest similarity was observed between Chinese varieties. 3. The similarity of 129 varieties were tested and it was 22.5%, 23.5% in female and male respectively. 4. The electrophoretic protein patterns in 129 varieties were tested and variation was found in 109 patterns in female and 112 in male. 5. The frequency of the each specified protein band in female and male having variation in protein bands in each variety was found averagely 6.6%. 6. The distribution frequency of the classified 28 protein bands in both the sexes within each geographical origin was variable from 0% to 100%. 7. Among the classified 28 protein bands, HP 11 protein band was found common in all the varieties tested. 8. HP 3 and HP 4 protein bands in female showed high density in electropherograms than in male.

• Journal of Sericultural and Entomological Science
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• v.14 no.1
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• pp.9-13
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• 1972

On the seventh day of mounting male and feamale cocoons are distinguished. A part of those male and female pupae is irradiated for 40 min. with 1,000r-ray irradiation. Those eggs obtained from the irradiated pupae are divided into six groups of 5, 15, 45, 90, 720 and 2,400 minutes after laying. The cahanges of accid soluble phosphorus in the each group of eggs are as follows. 1. In the control group of the maximum quantity in acid soluble phosphorus was 1,456r/100mg D.P. in the 2,400 minutes group, while the minimum quantity was 1,233r/100mg D.P. in the 720 minutes group. 2. In the mated group of ＊irradiated female moths and control male moths, the quantity of acid soluble phoshorus was small as compared with the control group in the five minute group of 1,288r/100mg D.P. and in the 15 minutes group of 1,299r/100mg D.P. while the quantity increased to 1,484r/100mg D.P. in the 45 minutes group. The quantity began to decrease again to 1,400r/100mg D.P. in the 2,400 minutes group which was smaller than that of the control group. The quantity was slightly small in the silkworm eggs laid in the early stage when compared with that of mated group of ＊irradiated male moths and control female moths. Both groups showed the larger quantity in the 720 minutes group than that of the control group. The quantity of acid soluble phosphorus in the mated group of control female moths .and ＊irradiated male moths was larger in variation than in the mated group of control male moths and ＊irradiated female moths. 3. In the mated group of ＊irradiated male and female moths the largerst quantity was 1,760r/100ms D.P. in 2,400 minutes group and second was 1,736r/100mg D.P. in 90 minutes group, and third was 1,288r/100mg D. P., in 5 minutes group. Generally the quantity was small in silkworm eggs laid by the irradiated one in the early stage than the control group, but in the later period of egg the quantity began to increase more than that of control group.

• Journal of Sericultural and Entomological Science
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• v.47 no.1
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• pp.12-17
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• 2005

To develop technique for the production of P. tenuipes stromata on a large scale, the infection of P. tenuipes and the growth of stroma were investigated by silkworm (Bombyx mori) variety. Also, studied about biological activites of fruiting body formed on silkworm. Infection rate of the 5th instar larvae of the silkworm with P. tenuipes was the highest in Yangwonjam, followed by Hachojam, Baegokjam and Chilbojam in that order. Also, as the inoculation times was increased, infection rate tended to be raised. The rate of fruiting body formation of the silkworm pupae infected with P. tenuipes was the highest in Baegokjam, followed by Yangwonjam and Chilbojam in the order. But, actually the fruiting body formation of the 5th instar larvae of the silkworm tested was good in Chilbojam, followed by Yangwonjam and Baegokjam in that order in 3 times spraying inoculation. The fruiting bodies of Yangwonjam and Chilbojam infected with P. tenuipes had high amount of Mannitol, but Baegokjam and Hachojam had high concentration of Glucose on a dry weight basis. The mean content of total amino acid in the fruiting bodies of P. tenuipes was 1.03 ${\mu}mole/g$. The distribution rate of amino acid components decreased in the order of Arginine (12.2%)>Glycine (10.5%)> Proline (9.6)>Tyrosine (8.9%)>Serine>Leucine>Threonine. The most abundant amino acid in the fruiting bodies of the Baegokjam, Chilbojam and Hachojam infected with P. tenuipes was arginine, while Yangwonjam was Glycine. The most abundant fatty acid in P.tenuipes was Oleic acid on a dry weight basis. The unsaturated fatty acids such as Oleic acid, Linoleic acid and Linolenic acid accounted for more than 78% of the total fatty acids.