• Journal of Aquaculture
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• v.12 no.1
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• pp.39-45
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• 1999

In order to obtain the basic biological data for artificial seedling production of sea cucumber, Stichopus japonicus, the influence of water temperature and air dry for spawning induction, egg development and larvae rearing was investigated during the period from April, 1995 through September, 1995. Spawning induction rate by the water temperature was 6.0~17.5% and air dry was responsed 1.4~4.0%. Number of eggs spawned of Stichopus japonicus were $50~500\times10^4$ individuals, the fertilization and hatching rate were ranged 84.0~96.0%, 71.4~84.6% respectively. The fertilized egg of Stichopus japonicus appeared mean diameter of $154{\mu}m$. At a constant water temperature of $23^{circ)C$, it become 4 tell stage from fertilization after 2 hours 10 minutes, hatching larvae after 14 hours half, auricularia larvae after 3 days, doliolaria larvare after 11 days and pentactula larvae after 15 days ready for settlement. The suitable food in the larvae reared for 17 days after fertilization were shown the best growth and survival in the larvae food of Chaetoceros calcitrans. Optimum density for larvae rearing were maintained of the larval density lower than 2 individuals/ml.

• The Korean Journal of Soil Zoology
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• v.6 no.1_2
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• pp.33-36
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• 2001

This study was carried out to screen 11 peony varieties collected for resistance to northern root-knot nematode, Meloidogyne hapla. The larval population of Meloidogyne halpa to the Uisongjakyak, Taebaekjakyak, Doseo, EP368, EP512 peony were detected high denisties with individuals of 98-173 per 300 ml soil, but Sabeol, Yongsu, Kimchon, Pl23 peony showed low number of larvar with 21-60. The root rot were lowered in Yongsu, Kimchon peony than Uisongjakyak, Taebaekjakyak, EP368, EP512. It seems to involved with densities of 2nd juvernile population in that rot rate of root was increased as increase of 2nd stage larvae. Two peony, Uisongjakyak, Taebaekjakyak were susceptable to M. hapla with high egg mass formation which showed 49,28 in each root. And Yongsu, Doseo, EP368, EP512 were Mid resistance with 1-15 egg mass of each root. Whereas Sabeol, Kimchon, Pl23, EP337, EP425 were found to be resistant to M, hapla with few egg mass formation of 4-7 each root.

• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.86-94
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• 2015

Chironomous is aquatic insect belonging to order Diptera, family Chironomidae. Their larval stage can be found mainly in aquatic benthic environment, hence good model organism to study environmental toxicology assessments and consider as useful bio indicators of contamination of the aquatic environment. In this study, Chironomus Heat Shock Proteins, Cytochrome 450, Glutathione S-transferase, Serine-type endopeptidase gene expressions were compared between polluted field areas (Chironomus plumosus) and under laboratory conditions (Chironomus riparious) to investigate molecular indicators for environmental contaminant stress assessment. Heavy metal (Al, Fe, Mn, Cu, Cr, Zn, Se, Pb, As, Cd) concentrations in sediments collected from three study areas exceeded the reference values. Moreover, HSPs, CYP450 and GST gene expression except SP for C. plumosus showed higher expression than C. riparious gene expression. Similar gene expression pattern was observed in C. riparious that exposed environment waters up to 96 h when compared to C. plumosus exposed to waters that grown in lab conditions. In summary, this comparative gene expression analysis in Chironomous between field and laboratory condition gave useful information to select candidate molecular indicators in heavy metal contaminations in the environment.

• International Journal of Industrial Entomology and Biomaterials
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• v.38 no.2
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• pp.38-50
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• 2019

We investigated the developmental characteristics and life cycle of the lawn cutworm, Spodoptera depravata (Lepidoptera: Noctuidae), which is one of the most important pests causing economic damage in grass production. For larval culture, we provided the zoysiagrass at $25^{\circ}C$ and $60{\pm}5%$ humidity. The durations of the developmental stages were as follows: $4.11{\pm}0.19$ days for eggs, $25.17{\pm}3.02$ for larvae, $8.80{\pm}0.28$ for pupae, and $7.57{\pm}0.95$ for adults. We grew the larvae to the 7th instar stage, unlike previous studies, in which it was assumed that the 6th instar was the final age. There was a significant positive correlation between the body length and head capsule width of each instar larvae. In terms of morphology, the eggs changed from light green immediately following oviposition to black as they developed, and the grass-fed larvae changed from light yellow immediately after hatching to green as development continued. We observed a pattern of black spots at regular intervals on the dorsal sides of the abdomens of the final instar larvae. Furthermore, we detected two notable designs on the dorsal side of the front of the head. The pupal colors changed from light brown and green immediately after pupation, to dark brown as the pupal cuticle hardened. The wingspans of the adults were similar in both sexes. However, the forewings of the males had obvious outer lines and eyespots with dark gray-brown backgrounds, whereas the corresponding features on the female forewings were less obvious. The oviposition preperiod was 2.11 days, the oviposition period was 4.2 days, the average fecundity per female was approximately 341 eggs, and the hatching rate was approximately 76.1%.

• Parasites, Hosts and Diseases
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• v.57 no.4
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• pp.423-427
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• 2019

Coenurosis is an important zoonotic helminthic disease caused by the larval stage of the tapeworm Taenia multiceps. This parasite typically infects the brain of the intermediate hosts, including sheep, goat, cattle and even humans. We report a case of T. multiceps infection in a yak confirmed by clinical symptoms, morphological characteristics, and molecular and phylogenetic analyses. The coenurus was thin-walled, whitish, and spherical in shape with a diameter of 10 cm. The parasite species was identified as T. multiceps by PCR amplification and sequencing of the 18S rRNA, cox1 and nad1 genes. Three gene sequences all showed high homology (all above 97%) with the reference sequences from different hosts. Moreover, phylogenetic reconstructions with the 3 published Taenia gene sequences confirmed that the Qinghai yak isolate was closely related to T. multiceps. Although there are advanced diagnosis and treatment methods for coenurosis, early infection is difficult to diagnose. Importantly, the findings of yak infection case should not be ignored due to its zoonotic potential.

• Entomological Research
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• v.48 no.5
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• pp.416-428
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• 2018

To gain an insight into the function of heat shock proteins (HSPs) in insects during thermal stress, three HSP cDNAs were identified in the transcriptome of adult Heortia vitessoides, one of the most destructive defoliating pests in Aquilaria sinensis (Loureiro) Sprenger forests. The open reading frames of HvHsp60, HvHsp70, and HvHsp90 were 1,719, 2,070, and 2,151 bp in length, respectively, and encoded proteins with molecular weights of 61.05, 75.02, and 82.23 kDa, respectively. Sequence analysis revealed that all three HSPs were highly conserved in structure. Regarding the stage-specific expression profiles, HvHsp60, HvHsp70, and HvHsp90 mRNAs were detected in all developmental stages. Regarding the tissue-specific expression profiles, the expression levels of the three HSP genes were different in various larval and adult tissues. Moreover, the expression patterns of heat-stressed larvae, pupae, and adults indicated that HvHsp60, HvHsp70, and HvHsp90 were heat-inducible. In particular, HvHsp60 transcripts increased dramatically in larvae and pupae that were heat-stressed at $40^{\circ}C$ and were upregulated in adults that were heat-stressed at $35^{\circ}C$ and $40^{\circ}C$. The expression of HvHsp70 significantly increased in all of the three different developmental stages at $35^{\circ}C$, $40^{\circ}C$, and $45^{\circ}C$. The expression of HvHsp90 obviously increased at $30^{\circ}C$, $35^{\circ}C$, and $40^{\circ}C$ in larvae and could be induced at $35^{\circ}C$ in pupae and adults. The results suggest that HSP60, HSP70, and HSP90 play a major role in protecting H. vitessoides against high-temperature stress.

• Journal of Sericultural and Entomological Science
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• v.14 no.1
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• pp.15-24
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• 1972

During the autumn-rearing season of 1971, at the silkworm rearing house at the college of agriculture, Seoul national university in Korea, the authors carried out a series of experiments (1) on the susceptibility of four important silkworm pathogens (Aspergillus flavus, Bacillus thuringiensis, Aspergillus oryzae, and Isaria farinosa) to Halamid (Tosylchloramide Sodium), (2) on the acute toxicity of Halamid to silkworm larvae at every instar, (3) on the inhibiting effect of Halamid to the attack of two silkworm infections, fungal muscardine and viral jundice, and the chronic toxicity of Halamid to silkworm larvae, and (4) on the yield and quality of the raw silk harvested from the Halamid treated silkworms. As the results of the experiments the authors found that Halamid could be applied usefully to silk worm rearing industry as an effective disinfectant for both silkworms themselves and their envir onmental articles, rearing houses and tools, also that Halamid exerts its disinfectant effect most efficiently as a disinfectant for silkworms when sprayed in 2% or 3% aqueous solution every second day throughout all tile instars of larval stage.

• Journal of Sericultural and Entomological Science
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• v.22 no.2
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• pp.1-7
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• 1981

Diallel crosses among six silkworm varieties were used as the materials by the randomized block design. and combining ability tests were conducted to determine the relationships between parents and their F$_1$ hybrids. The six parents and their 30 F$_1$ crosses were evaluated for five quantitative characters in each female and male silkworms. Mean values of period(days) of larval stage in mid-parent were more than those of each F$_1$ hybrids. Highly significant differences were shown in the total cocoon weight and weight of cocoon layer of silkworms in F$_1$ hybrids of 111$\times$114, 111$\times$ yunil, 114$\times$yunil and those of reciprocal crosses. From the results, it was recognized that varieties A(111), D(114) and F(yunil) were useful varieties as the parents in breeding of silkworms for increasing the total cocoon weight and weight of cocoon layer, etc. Differences among crosses in apparent degree of heterosis existed for total cocoon weight of cocoon layer and cocoon layer ratio, etc. Mean square values of GCA (general combining ability) were more greater than those of SCA(specific combining ability) for period(days) of larval stage, period (days) of 5th instar and cocoon layer ratio of silkworms. The effects of GCA were differ from parents and characters and the effects of SCA were also differ from parents, characters and crosses.

• Journal of Aquaculture
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• v.16 no.4
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• pp.233-239
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• 2003

Growth and activities of digestive enzymes in slime flounder (Microstomus achne) larvae were measured from hatching to near the end of larval development (day 58). Larvae reared under starved and fed conditions and the changes of acid phosphatase (ACPase) specific activity, alkaline phosphatase (ALPase) specific activity, trypsin-like enzyme activity and pepsin-like enzyme activity were described with growth and developmental stage of larvae. Total length of the starved larvae was gradually increased for 7 days post hatching and then almost unchanged. Total length of the fed larvae ranged from 5.13$\pm$0.178 mm at the day of hatching to 13.43$\pm$1.395 mm at 58 days after hatching. In starved group, dry body weight decreased from 0.l0$\pm$0.020 mg at the day of hatching to 0.05$\pm$0.012 mg at 12 days after hatching. Dry body weight of fed larvae decreased during the prelarva stage like starved group and then gradually increased. ACPase and ALPase specific activity in the starved larvae increased until all larvae died, however those activities in the fed larvae increased until 20 days and then decreased until 58 days after hatching, with no significant difference between groups. Trypsin-like enzyme activity in the starved larvae was unchanged until 3 days and then was the highest on 5 days after hatching, but not detected after completion of yolksac absorption. Those of fed larvae decreased until 3 days and sharply increased until completion of yolksac absorption. The highest trypsin-like enzyme activity in the fed group was observed at 20 days after hatching. Trypsin-like enzyme activity in the fed larvae was significantly higher than that in the starved larvae from 8 days after hatching. Pepsin-like enzyme activity was increased in 5 days after hatching in both groups. There was significant difference at 8 and 10 days after hatching between both groups. Based on above results, digestive enzyme activities were correspondingly changed to a growth and morphological transformation. Trypsin-like enzyme and pepsin-like enzyme activities are able to be a useful indices for health and growth status in larval slime flounder, because there was significant difference in digestive enzyme activities with developmental stages, growth or feed supply.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.201-212
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• 2007

This study was conducted to investigate the biology of three species, Tipula latemarginata Alexander, T. nova Walker and T. aino Alexander, of the Genus Tipula in Korea. Field surveys for the biology of the species were carried out at the three sites of Neaseong Stream area in Bongwha County from January 2001 to December 2005. Also many individuals of the species were reared in laboratory to investigate the biology. The larval habitats of the species were streams, rivers, paddy fields, damp earth or leaky revetments. The Tipula larvae were herbivorous. Newly-hatched first instar larvae fed on soft algae, and the larvae gradually fed on leaves, stems and roots of a variety of plants or hard leaf litters, as they grew. During the molting of the larvae their body kept moving from left to right and up and down. Molting usually took not more than 2 hours, and about four hours after molting, the larvae started to eat heavily. The Tipula larvae in aquatic places moved to drier land for pupation and went through short prepupal stage lasting 1-2 days for pupation at fourth instar larval stage. When emerging, the Tipula pupae placed their head and thorax on the earth, but the other parts in the earth. Emergence from the pupal case required about 20 min. to one hour. Mating of Tipula adults took place within 5-7min. after emergence and the duration of mating was about 40 min. The female adults of the species laid eggs by walking with 3 pairs of legs over the damp earth or algal beds. Their body was positioned vertically on the ground with their wings spread $120^{\circ}$ and legs landed on the surface. The oviposition usually took place from one day to 4 days after emergence and the number of eggs carried by female adults were an average of 501-760 per individual. Tipula adults didn't normally feed, and drank water only occasionally. For a few days after emergence, the adults reared in the laboratory rarely drank water. As they neared to death, however, they frequently drank water. The longevity of adults reared in the laboratory with only water during the summer was ca. 4-9 days and males usually survived a little longer than females. The longevity of T. nova was increased 3 times or more as much by feeding them 3% sugar water. Male adults of T. latemarginata outnumbered female adults by 2.6 : 1 in the fields.