• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.237-244
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• 1992

In order to observe the infectivity, growth and development and adult morphology of Metorchis orientalis, a total of 40 chicks were experimentally infected with 100 metacercariae respectively, collected from Pseuderasbora larva. The worms of various developmental stages were recovered from chicks at 1.5, 3, 5, 7, 9, 11, 1:k and 21 days after infection, and they were prepared for morphological observations and measurements. All of the worms were found in the gallbladders of chicks, and their recovery rate was 32% in average. The growth of the body was rapid from 9 to 11 days after infection. The genital primordia appeared in 1.5 and 3-day old worms, and ovary and testes were first observed in 5-day old worms. Thereafter, genital organs gradually matured and completed up to 11 days after infection. The adult worm was leaf-like, and possessed a con- voluted tubular seminal vesicle, an ovoid ovary, a sac-like seminal receptacle, 2 lobed-testes and follicular vitellaria. Eggs were $31.9{\times}15.3{\;}\mu\textrm{m}$ in average size, ellipsoid to elliptical in shape and possessed abopercular thickenings. From the above results, it is concluded that M. orientalis grows in sigmoid pattern in chicks, and their genital organs fully matul.e between days 9 and 11. It is also confirmed that a chick is a new definitive host of M. orientalis.

• KSBB Journal
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• v.15 no.1
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• pp.100-105
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• 2000

Optimal medium composition, culture conditions, characteristics of phase variation and activity of insecticidal toxin by Xenorhabdus nematophilus isolated and identified from Korean entomopathogenic nematode Steinernema carpocapsae were examined. Optimal medium composition of this strain was 50-70 g/L yeast extract, 3 g/L $K_{2}HPO_{4}$, 1g/L $NH_{4}H_{2}PO_{4}$, 2g/L ${MgSO}_4$$\cdot$${7H}_{2}O$, 10g/L NaCl and, these, yeast extract was found as a limiting nutrient for cell growth. When Monod equation was applied, maxmum specific growth rate and Monod constant were estimated as 0.13 $hr^{-1}$ and 20g/L, respectively. The pH of culture medium increased up to 8.5-9.5 regardless of initial pH 6-7 as the cells continued to grow. The specific growth rate in a 7 L fermentor was 0.18 $hr^{-1}$, which was enhancement 1.4 fold compared to a flask culture. In case of phase variation, phase I fraction was maintained above 90% at the stationary phase for both flask and fermentor cultures. According to oral toxicity test of Gallena mellonella by Xenorhabdus nematophilus, the addition of cell pellets into feed inhibited normal growth of insect larvae and killed completely then after 20 days cultivation. When culture supernatant of this strain was injected into hemolymph of insect larva, the toxicity was strongest at 24hr cultivation in the early exponential phase and gradually decreased as the culture time proceeded.

• Journal of Aquaculture
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• v.10 no.2
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• pp.123-131
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• 1997

Growth of triploid abalone, Haliotis discus hannai induced by cody (3$^{\circ}C$) shock and its feed efficiency were investigated from larva to adult for 51 months. After 51 months from triploidy induction, the triploid abalones have outgrown to diploid abalones in shell length and total weight. Triploid abalones with inhibition of extrusion of first polar body (3n-1pb) were outgrown to diploid abalones, however, triploid abalones with inhibition of extrusion of second polar body (3n-2pb) were not significantly different from diploid controls in shell length and total weight through the whole rearing period (P<0.05), because of their heterozygosity differences. Daily feeding rates and feed conversion rates decreased with the growth of abalones and both rates had no differnce between two experimental groups. After 51 months from inducing triploid, conditin index of triploid abalone (64.1%) was higher than that of diploid control (59.4%) (P<0.05). Survival rate was 63.0% in triploid group (3n-1pb 62.0%, 3n-2pb 64.0%) and 62.0% in diploid group during the experimental period.

• Korean journal of applied entomology
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• v.5_6
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• pp.27-32
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• 1968

The larval instar of Scintillatrix djingischani OBENBERGER WES determined by measuring the head width of the larvae, some of which were bred in the room and the other collected in orchards during four years(1963-1966). Their growth ratio and variation were also studied. 1) The variation curve of the head width of the Iarvae distinctly appeared to be seven (7) curves, which seemed to have lived to be over seven(7) instars after six(6) times of molting. 2) In general, tile larvae live out to be 6-7 instar. Those pupated at 6th instar seem to over winter in tissue from November as matured. And those pupated in late Spring or early Summer after over wintering in canbium seem to be at 7th instar. 3) The standard deviation of the head width tends to grow larger except at 1st and 7th instar, while the coefficient of variation tends to decrease according as the number of instar increases. The growth ratio was found to decrease according as the number of instar increase except at 1 at and 2 nd instar. 4) To the growth of tee larval head width of this insect, Games and Campbell's formula was more applicable than Dyar's. 5) From the activties of larvae it is presumed that those bred in the year over winter in phelloderm or canbium at the 2 nd-3 rd instar, and the matured (2 year old) emerge the next year after over wintering in cambium or tissue at the 5th or 6th instar.

• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.27-31
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• 2005

Early larval growth for total length (TL) and body weight (BW) in flesh prawn (Fenneropenaeus chinensis) was studied from hatching to 25 days after hatching. Mean total length at nauplius and zoea stages was 0.21-0.39 mm and 0.62-1.03 mm, respectively. Mean total length of mysis stage grew from 1.28 mm (9 days after hatching) to 5.98 mm (21 days after hatching). The increase of body weight during experimental period showed step by step growth pattern due to metamorphosis of this species. The relationship between BW and TL from hatching to 25 days after hatching was BW = 2E-5TL/sup 4.1707/ (r²= 0.9746).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.551-556
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• 2002

We have experimentally evaluated the content of thyroid hormones (THs), the growth and activity of larval rockfish (Sebastes schiegeli) born from parturient mother fish injected with 20 $\mu$g/g BW of 3,5,3-triiodo-L-thyronine ($T_{3}$). There was no difference of L-thyroxine ($T_{4}$) levels between controls (sham control and control) and $T_{3}$ groups in yolk-sac larvae just born from broodstock, while $T_{3}$level of $T_{3}$ group was significantly increased compared with controls. In addition, the both larval $T_{3}$ and $T_{4}$ levels in $T_{3}$ group were always higher than those of control during experimental period. Also, there were significant differences in the development of larvae from the two groups. The larval growth in total length and body weight according to the elapsed days after parturition showed the linear and curve equations, respectively, and the slopes of $T_{3}$ group were significantly higher than those of control. The survival rate of larvae in $T_{3}$ group was higher than that of control. Although the survival rate in $T_{3}$ group under the condition of starvation was significantly depressed compared with the control, larval swimming index in $T_{3}$ group was higher than control. Finally, these findings suggest that the exogenous $T_{3}$ could be transferred into hatched larvae in parturient rockfish by maternal injection, and subsequently the exogenous hormone could play some roles on physiological metabolism of larvae after parturition and may confer a distinct advantage to the fragile larvae during the early developmental stage.

• Korean journal of applied entomology
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• v.39 no.3
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• pp.135-140
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• 2000

Development and reproduction of the cotton caterpillar, Palpita indica, were investigatedunder different temperatures (15 .O, 17.5, 20.0, 22.5, 25 .O, 27.5, 30.0, 32.5, and 35 .O$^{\circ}$C). Duration fromegg to pre-adult of the cotton caterpillar were ranged from 68.6 days at 175$^{\circ}$C to 19.7 days at 35.0% (3.5times shorter growth period compared with that at 17S$^{\circ}$C). At 15.0$^{\circ}$C, cotton caterpillar eggs developedto the last larval instar but were not able to go through the pupal stage. The lower developmentalthreshold temperatures and degree-days of egg, larva, pupa, and complete development were 13.4, 10.6,11.6, and 11.5"C and 55.3,251.5, 138.3, and 479.8 degree days, respectively. The hatching, pupation andemergence rates were higher at 25.0eC and 27.5"C compared with other temperatures. The survival ratefrom the hatched larva to adult was the highest at 27.5"C. The preoviposition and the adult longevity were11.5 and 30.6 days at 17.5"C and 1.5 and 9.2 days at 35.0$^{\circ}$C, respectively. The mean fecundity perfemales was greater at 25.0$^{\circ}$C and 27.5"C compared with other temperatures. Mean generation time indays (T) was shorter on higher temperature. Net reproductive rate per generation (R,) was the lowest atthe highest temperature as well as at the lowest, and it was 199.1 which was the highest at 27.5"C. Theintrinsic rate of natural increase (r,) was highest at 30.0$^{\circ}$C as 0.148. As a result, optimum ranges oftemperature for P. indica growth were between 25.0-32.5"C .emperature for P. indica growth were between 25.0-32.5"C .t;C .

• Journal of fish pathology
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• v.2 no.1
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• pp.1-18
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• 1989

In Korea, studies on a Nematode, Anguillicola crassa parasitic in the air bladder of eel are not yet reported. This reason led the author to study the parasitic species, state and life history of the A. crassa parasitized in the air bladder of eel in order to take effective control measures against its damage. The size of fully developed eggs was 80 to $92(86.7){\times}62$ to $71(67.4)\;{\mu}m$, larva was 210 to $240(225){\times}18$ to $23(20.6)\;{\mu}m$. The intermediate host of A. crassa was Thermocyclops hyalinus, it was capable for parasitizing the eel after 4 days of invasion and then the size of larva was 360 to $420(390){\times}28$ to $35(31)\;{\mu}m$. Fifty days after eel had ingested the Thermocyclops hyalinus infected with larva of A. crassa, the larvae matured into adult worms in the air bladder of eel. The size of detected adult worms was 7.3 to $31.0(16.5){\times}0.5$ to 2.2(1.2) mm, 4.9 to $13.3(8.3){\times}0.3$ to 0.9(0.4) mm. Investigating the morphology of the worms, they were identified as A. crassa. Monthly the parasitic rate of the worms in the eel was high in June, September and December, but low in January to March. After the investigation on the significance between non-parasitic fish and parasitic fish, it was not significant, therefore it can be considered that there is no effect of infection in the growth of eel. Any abnormality of eels air bladder tissue was not seen by the infection of A. crassa. At 25.0 to $26.7^{\circ}C$ of water temperature the death time of Thermocyclops hyalinus by masoten treatment was 14 hours in 0.5 ppm, 20 hours in 0.4 ppm, 22 hours in 0.3 ppm, 30 hours in 0.2 ppm and 42 hours in 0.1 ppm.

• Korean journal of applied entomology
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• v.25 no.2 s.67
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• pp.85-92
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• 1986

This study was conducted to investigate host plant, bionomics, and damage on Bamboo Leaf Rollers in Chonnam area. Species of the leaf rollers attacking the bamboo trees in Chonnam area were Microstega jessica (Butler) and Sinibotys evenoralis (Walker). Among these species, M. jessica (B.) and S. evenoralis (W.) were observed in Damyang but S. evenoralis (W.) alone was found in Naju and Hwasoon. Among the 4 host plant species observed, Phyllostachys nigra var. henonis S., and P. nigra M. were first recorded as host plants of M. jessica (B.), and P. nigra var. henonis (S.) as host plant of S. evenoralis (W.). The occurrence of the M. jessica (B). was once a year with the peak about late May, whereas the occurrence of S. evenoralis (W.) was 2 times a year and the peaks were early June and mid-July, respectively. The average periods of each stage of M. jessica (B.) were 8 days for egg, 293 days for larva, 16 days for pupa, and the longevity of the adult was 12 days for females and 9 days for males. The average periods of each stage of S. evenoralis (W.) were in 1st generation, 11 days for egg, 28 days for larva, 12 days for pupa, and the longevity of the adults was 18 days for females and 15 days for males; and 2nd generation was 7 days for egg, 261 days for larva, 20 days for pupa, and the longevity of the adults was 11 days for females and 10 days for males. The time of most adult emergence of M. jessica (B.) was from 6 p.m. to 4 a.m. and the peak was 8 p.m. to 10 p.m. M. jessica (B,) overwintered as 6th instals in Bamboo shoot sheath but S. evenoralis (W.) overwintered as $1st{\sim}2nd$ instals on the tree leaves of Bamboo. The percentage of damaged leaves with different heights of Bamboo trees were 67.1% at upper portion, 19.0% at middle portion, 14.0% at lower portion. The percentage of damaged loaves with different Bamboo species was 57.0% on P. nigra var. henonis S., 36.5% on P. bambusoides S. et Z., 14.5% on P. pubescens M.. It was showed highly significant negative correlation between percentage of damaged bamboo leaves an tree growth stages.($r=-0.739^{**}$)

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.610-615
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• 2020

Edible insects might be used as a means to solve food insecurity caused by population growth. Many studies have investigated the biological activity of insects; however, few studies have investigated the nutritional value of insects. Therefore, the aim of this study was to investigate the nutritional value of Allomyrina dichotoma larva protein (ADP) as a source of protein replacement. In vivo studies were conducted to determine the food efficiency ratio (FER), protein efficiency ratio (PER), and true digestibility (TD) of ADP. Experiments were conducted in 3 groups of 8 animals per group using twenty-four 4-week-old SD rats. The experimental groups included the general diet group (Con), in which 20% of the total Kcal in the diet was composed of casein protein, and the ADP group (ADP), in which 20% of the total Kcal was composed of ADP protein, and a non-protein diet group (NP) to measure the protein (metabolic fecal nitrogen) excreted by metabolic processes in the body. As a result of this experiment, we found that the FERs were 0.52 and 0.41 in the casein protein intake (Con) and ADP groups, respectively, thus showing a significantly lower level in the ADP group. The PERs of ADP and Con were 2.39 and 2.63, respectively. The TD of Con and ADP were 91% and 80%, respectively.