• Korean journal of applied entomology
• /
• v.56 no.2
• /
• pp.203-212
• /
• 2017

Thirty-three species of insect pests including of two-spotted spider mite, Tetranychus urticae Koch, and air-breathing land snail, Acusta despecta Sowerby, were observed on mulberry for producing mulberry fruits in Jeonbuk province from 2015 to 2016. Of these, 8 species of insect pests, including of mulberry thrips, Pseudodendrothrips mori Niwa, are regarded as major insect pests. Of the 25 species observed before harvesting, 6 species-P. mori, Anomoneura mori, Pseudaulacaspis pentagona, Baris deplanata, Menophra atrilineata and T. urticae-are regarded as major insect pests. In contrast, of the 20 species observed after harvesting, 5 species-P. mori, P. pentagona, Glyphodes pyloalis Walker, Hyphantria cunea Drury and T. urticae-are regarded as major insect pests. Eight of the major insect pest species and nine other insect pest species-including Hexcacentrus unicolor Serville, Malcus japonicus Ishihara et Hasegawa, Halyomorpha halys stal, Xylosandrus germanus Blandford, four species of Repidoptera (Bombyx mandarina Moore, Euproctis subflava Bremer, Acronicta major Bremer, Agrotis trifurca Butler), and Acusta despecta Sowerby-were observed at all sites studied, although occurrence of the insect pests observed on mulberry varied from site to site.

• Journal of Sericultural and Entomological Science
• /
• v.41 no.1
• /
• pp.20-28
• /
• 1999

Color qualities investigated on the basis of Munsell code and Korean standard color code for the cocoons from various strain of mulberry silkworm, Bombyx mori. 16 of different color qualities were identified from 21 of original silworm strains, and determinated international name with the revision of Korean color name for cocoon. The various cocoon color confirmed on the sphere from 567 to 593 nm wavelength, 78% of those located at the region about 580 nm (575~584) of sensitive "color difference limen". Y gene engaged broad ranges of wavelength (575~593 nm) in the color expression, by contrast with other genes of Pk (593 nm), F (584~593), Grc and relative G group (567~570 nm), on the transmission of carotenoid or flavonoid color substance. YC gene expression by original silk worm strain was also distinguished by those variation of specific yellow than other colors from Grc, GaGb, Gc, and YPkF. Appearance of chrome yellow cocoon was dominant than other yellow in the cross among vivid yellow group. F1 of pin${\times}$green produced the cocoon of yellow such as "additive mixture" as color light, however, most of the hybrid between yellow cocoon showed the color similar to "subtractive mixture" as a mixture of dyestuff. Hybrid cocoons among yellow or green colors were decreased their hue, value, and chroma, than those of parent. Diallel cross among the strain of various green cocoon suggest the existence of Grc, Ga, Gb, Gc genes. Cream colored cocoon of B. mandarina was differed from other yellow cocoon of Bobyx mori B. mori. Y$^A$ with Ymc showed the similar role of Y with C, therefore, segregated yellow cocoon from the B. mori${\times}$B. mandarina (+$^YC/Y^AYmc$). YC expression of $Y^AY$mc genes might be suppressed by deficiency of outer layer sericin on the middle division of silk giand in the B. mandarina.

• Journal of Sericultural and Entomological Science
• /
• v.34 no.2
• /
• pp.26-31
• /
• 1992

Flacherie virus (FV) and Densonucleosis virus (DNV) of the silkworm, Bombyx mori, which give the most severest damage to the silk production in korea, were fed on the mulberry wild silkworm, Bombyx mori mandarina, the mulberry pyralid, Gryphodes phyloalis, and the American fall webworm, Hypantria cunea, to investigate cross infectivity by serological and histopathological at observation. By the Ouchterlony's double difusion test the mulberry wild silkworm was infected with both FV and DNV type 1 (DNV-1) and the mulberry pyralid with DNV-1, so those were confirmed the cross infection. But the American fall webworm was not recognized the cross infection by the same method. The infection and multiplication of the FV in the mulberry wild silkworm was observed in the cytoplasm of the goblet cell with the appearance of the virus-specific vesicle. In DNV-1 infection to the mulberry wild silkworm and the mulberry pyralid, the nuclei of columnar cell in the midgut of both insects was hypertrophied and the nuclei of midgut cell of the mulberry pyralid positively stained with the feulgen stain. Multiplication of DNV-1 in the midgut cell of the mulberry wild silkworm was replicated in two different patterens as linear arrays and large masses, while that of DNV-1 in the muberry pyralid was multiplied as virus masses in several portion of the nuclei of the midgut cell.

• Journal of Sericultural and Entomological Science
• /
• v.43 no.2
• /
• pp.59-66
• /
• 2001

This study was conducted to elucidate phylogenetic relationships and genetic characterization of silkworms that might be recognized as the Korean native strains. Genetic characterization in isozymes and the proteins of larval hemolymph of 17 silkworms were observed by acrylamide gel eletrophoresis, on 12 genes; Bph, Bes, les, Amy-hc, Ict-A, -B, -D,-E,-H, Pfl, Pst, Lp. Gene frequencies in each locus were compared other geographic strains. Korean native strains were remarkably different from others considered as the genetic characterization of Korean native strains. Phylogenetic relationships in Korean native strains were analysed using RAPD-PCR markers. A total of 40 primers were used and 346 bands of amplified DNA were generated from geographic strains. Genetic similarity based on the RAPD bands was used to construct phylogenetic dendrogram based on analysis of bard sharing data of amplified markers. Genetic similarity ranged from 0.595 to 0.860. In the genetic relationship based on dendrogram, they were classified into Bombyx mori group (including 16 domesticated silkworm strains) and B. mandarina group. The Bombyx mori group was separated into three sub-groups at the genetic similarity of 0.6930, including Korean, Japanese and Chinese groups. According to this result, the Korean native variety can be considered as a clearly different variety from other geographic strains. It may be concluded that the Korean native strains are also one of original geographic variety such as Japanese, Chinese, etc.