• Korean journal of applied entomology
• /
• v.59 no.4
• /
• pp.455-460
• /
• 2020

Rice grain damage caused by Paromius exiguus under various conditions in paddy fields was analyzed. One nymph of P. exiguus caused 2.7 pecky grains in brown rice in one day, and sixteen nymphs caused 132.3 pecky grains over sixteen days. The relationship between the inoculated nymphal density and the number of pecky grains was well described by a linear regression (Y = 8.8446X, r2 = 0.9622). When a pair of P. exiguus adults was inoculated in the heading stage of rice, the damage at the time of harvesting consisted of 40.2% of cracked rice and 30.5% of pecky rice among whole rice grains. Inoculation of 16 pairs resulted in 81.7% of cracked rice and 74.5% of pecky rice. The damage analysis indicated that the quantity of ripened rice decreased as the damage started earlier in the heading stage of rice. On the contrary, the proportion of cracked and pecky rice rapidly increased from the heading time until 28 days after heading of the rice grains.

• Molecules and Cells
• /
• v.28 no.3
• /
• pp.155-165
• /
• 2009

The newly sequenced complete mitochondrial genome of the brown marmorated stink bug, Halyomorpha halys($St{\aa}l$) (Hemiptera: Pentatomidae), is a circular molecule of 16,518 bp with a total A+T content of 76.4% and two extensive repeat regions in A+T rich region. Nucleotide composition and codon usage of H. halys are about average when compared with values observed in 19 other published hemipteran mitochondrial genomes. Phylogenetic analyses using these 20 hemipteran mitochondrial genomes support the currently accepted hypothesis that suborders Heteroptera and Auchenorrhyncha form a monophyletic group. The mitochondrial gene arrangements of the 20 genomes are also consistent with our results.

• The Korean Journal of Zoology
• /
• v.23 no.1
• /
• pp.13-24
• /
• 1980

The germarium contains the apical complex consisting of a multinucleated syncytium. Apical complex has a nutritive role for the early spermatogonia. Trophocytes are irregularly shaped and are distributed throughout the space from spermatogonial cysts to sperm bundles, and they increase in size by endopolyploidization. As meiotic divisions are not complete until the final moult, spermatogenesis continues even in the adult. Chromosome number is 2n=24. Spermiogenesis is divided into seven stages in terms of chromatin concentration, cytoplasmic granules, and the nuclear size and shape. These stages could be grouped into the spherical, the elongating and the rodform spermatids in shape.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.56 no.4
• /
• pp.569-574
• /
• 2023

A single specimen (30.35 mm standard length) of Ptereleotris evides was collected from the southern coast of Jejudo Island, Korea, in September 2017 during a skin diving outing. Ptereleotris evides is characterized by having a slightly elongated body, six spines on the 1^st dorsal fin, one spine and 25 soft rays on the 2^nd dorsal fin, 22 pectoral fin rays, one spine and four soft rays on the pelvic fin, one spine and 25 soft rays on the anal fin, and no disc in pelvic fin. This species differs from the congeneric species, P. hanae and P. heteroptera in having no elongated rays on the caudal fin and a black spot at the ventral margin of the caudal peduncle, respectively. Molecular analysis results based on mitochondrial DNA cytochrome c oxidase subunit I (COI) sequences showed that our specimen almost corresponded to P. evides (99.82%) sequences from registered at the NCBI. As this is the first record of P. evides in Korean waters, we propose a new Korean name for it, "Ga-mak-cheong-hwang-mun-jeol".

• Korean journal of applied entomology
• /
• v.41 no.1
• /
• pp.33-41
• /
• 2002

The mirid bug damages on grapevine were observed not only on young shoot and leaves (decoloration, deforming, and perforation) but also on fruits (black spot, corky scar, and young fruit shattering). Among 159 fields surveyed throughout the country, 113 fields (71%) were damaged, and the damages were relatively severer in the chief producing districts of grape vine, such as Gimpo, Anseong, Naju, Gimcheon, Buyeo, Daejeon, Yesan than other districts where grapevine yards were not concentrated. The severest shoot damages were observed in two grape vine yards of Naju (85%) and Gimpo (65%) in 1999. Three species of virid bugs were recognized on grape vine tree, Apoygus spinolae (Meyer-Dur), Apolygus lucorum (Meyer-Dur), and Orthotylus (Melanotrichus) flavosparsus(Sahlberg). Among them, A. spinolae was dominant species in the number of specimens collected. A. spinolae were collected on 10 host plants including Vitis vinifera L., Prunus armeniaca var. ansu Max., and prunus serrulata var. spontanea(Max.) Wils. and etc., and A. lucorum were collected on 10 species of plants, including Artemisia iwayomogi Kitamura, Artemisia princeps var. orientalis(Pampan) Hara and etc. Both A. spinolae and A. lucorum distributed widely in Korean grapevine yards.

• The Korean Journal of Zoology
• /
• v.14 no.4
• /
• pp.181-191
• /
• 1971

In Diplonichus esakii each ovary comprises five telotrophic ovarioles. In the fourth instar, the anterior part of the germarium consists of undifferentiated cells. The middle part contains a spherical trophic and the posterior part comprises young oocytes, followed by the upside downbell shape prefollicular tissue. The bell form is the standard characteristic in this instar larva, and the nutritive cord is found although somewhat indistinctly. In the fifth instar larva, the trophic core is elliptical form, and the oocyte is found at the base of the core. The oocytes are connected with the ocre by the nutritive cord. In the prefollicular tissue are also found some oocytes. In the adult, the vitellarium is filled by the developmental oocytes. The yolk granules inside each oocyte migrate from the base of the follicular epithelial cells to the center of the oocyte. Finally, the ooplasm of the oocyte becomes completely homogeneous. Therefore, according to the advancing of instars the nutritive cord developes completely before the oocyte has chorion and the follicular epithelial cell binucleates. The upper part of the ovariole consists of unchorionated oocytes, and the proximal part comprises chorionated oocytes in the adult.

• The Korean Journal of Zoology
• /
• v.24 no.2
• /
• pp.65-75
• /
• 1981

The formation of the acrosome during spermatogenesis in Gerris paludum was studied. The Golgi bodies are dispersed randomly in the cytoplasm at the early stage of the spermatocyte and get together to form several group of many bodies, and then they are equally divided into the spermatids by the meiotic divisions. The acroblast first appears in the form of a vesicle and soon an acrosomal granule is differentiated within it. The acroblast is separated from the acrosomal granule at the posterior of the nucleus and is finally sloughed off along the tail filament. The acrosome, after moving to the side of the nucleus opposite the mitochondrial derivatives, differentiates into two zones. The two basal bodies and the differentiated tip originate from the sheath. The basal bodies appear at the proximal part of the sheath simply in contact with the core on one side. During elongation and and narrowing of the acrosomes of the spermatids, they surround the one side at the base of the acrosome and finally all the other are immediately adjacent to the nucleus. The differentiated tip continues to the sheath at the anterior of the cores and is elongated prior to the two basal bodies. They appear to be contiguous twin-tubes, not a single granule in the later stage of the spermatids, and a group of the basal bodies in the sperm bundle.

• Korean journal of applied entomology
• /
• v.62 no.2
• /
• pp.83-87
• /
• 2023

Nysius plebeius is a major lygaeid pest of various cereal crops and ornamental plants in East Asian countries, including Korea. The complete mitochondrial genome of N. plebeius was characterized and found to comprise a total of 17,367 bp, which included 13 protein-coding genes, NADH dehydrogenase components (complex I, ND), cytochrome oxidase subunits (complex VI, COX), cytochrome oxidase b (CYPB), two ATP synthases, two ribosomal RNA genes, and 22 transfer RNAs. The GC content of 23%. It showed high sequence similarity to other Lygaeidae species, such as N. cymoides (94.5%), N. fuscovittatus (91.7%), and an unknown Nysius species (94.1%). This new N. plebeius mitochondrial genome can be widely used for evolutionary studies of Lygaeidae and to improve pest management practices.

• Korean journal of applied entomology
• /
• v.46 no.1 s.145
• /
• pp.79-85
• /
• 2007

From the surveys of 2005 and 2006 in Korea, Trissolicus nigripedius was found in four locations, i.e., Andong, Miryang, Namhae, and Suwon, and one of the major egg parasitoids of Dolycoris baccarum. T. nigripedius was also found to parasitize two other soybean bugs, Riptortus clavatus and Piezodous hybneri, from the field collection in 2005. Host acceptance behaviors of T. nigripedius consisting of drumming, oviposition, and marking were observed and compared on five species of soybean bugs. T. nigripedius showed the complete host acceptance behaviors on the eggs of D. baccarum, P. hybneri, and Halyomorpha halys. But T. nigripedius emerged only from the eggs of D. baccarum (96%) and P. hybneri (75%) after 24 hours of exposure. T. nigripedius did not mark on the eggs of R. clavatus and Nezara antennata during the observation of behavior, hence no egg deposition was made. However, T. nigripedius parasitized 20% and killed 30% of the eggs of R. clavatus when 24 hours were given for parasitization. T. nigripedius would be a potential biological control agent of D. baccarum and P. hybneri with ability of giving additional mortality on R. clavatus in soybean field.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.6
• /
• pp.1136-1142
• /
• 2012

The roles of paddy fields are re-evaluated as an artificial wetland. Although 44% of total aquatic invertebrates in South Korea are observed in a rice paddy, information of their distribution and characteristics of habitat use is limited yet. This study was carried out to provide information and characterizing distribution of community of aquatic invertebrates using a rice paddy through the South Korea. Aquatic invertebrates were collected at 284 sites of a rice paddy in South Korea from June to August, 2005, 2006 and 2007. We grouped sampling sites according to its species and population of aquatic invertebrates using a non-metric multidimensional scaling (NMDS). Total 21 orders 60 families 114 species were collected from a rice paddy. Coleoptera (25%), Heteroptera (17%), Diptera (17%) and Odonata (12%) were observed. Aquatic invertebrates were classified into three groups (Group 1: Gangwon, Gyeonggi and Chungbuk; Group 2: Chungnam, Jeonbuk, Jeonnam and Jeju; Group 3: Gyeongbuk and Kyeongnam). In Group 1, Muljarus japonicas distributed mainly Gangwondo and Chungbuk. In Group 2, Sigara nigroventralis and S. substriata were mainly observed. In Group 3, higher density of Daphnia sp. and Chironomidae gen. spp. was found in the southern part of Korea.