• Parasites, Hosts and Diseases
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• v.22 no.1
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• pp.78-84
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• 1984

In order to determine the infestation patterns for metacercaria of digenetic trematodes, several kinds of fresh-water and brackish-water fish were caught in River Hyungsan, Kyungpook Province, Korea and examined from March to October in 1983. They were collected by netting, fishing with rod and line, or using the bait of crushed oil cake in transparent plastic bowls, and were dissected into the flesh, scales and 6ns with tail, and then examined for the presence and infestation density of larval trematodes. Of the 11 kinds of fish examined, the encysted larvae of Exorchis oviformis were found all of them, Metagonimus yokogawai from 9 kinds, Cyathocotyle orientalis, Metacercaria hasegawai and Metorchis orientalis from 6 kinds, alld Clonorchis sinensis from 4 Kinds in the present study. In the intensity of infestation with Clonorchis sinensis, the Korean shiner, Gnathopogon atromaculatus Nichols et Pope, was the most heavily infected species, the average number of metacercariae per grata of fish flesh being 45.5, followed by the striped shiner, Puntungia hirxi Ibersenstein 11.6, and Southern top-Inouthed minnow, Pseudorasbora larva (Temminck et Shlegel) , 9.7. The intensity of infestation with the iwetagonimus larvae in 8 species of fresh-water fish was relatively low, and the average number per gram of flesh varied from 0.23 to 9.1. In comparison, the brackish-water fish were more heavily infected and the mean number of cysts per gram of flesh in the sweetfish, Plecoglossus altiwelis, was 32.9. The results of this study generally indicate that Clonorchis sinensis and Metagcnimus yckogawai infection may occur by consuming raw fresh-water fish caught in the river Hyungpook, Kyungpook Province, Korea.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.102-110
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• 1985

In order to determine the epidemiological pattern of the Paragonimus westermani, the infestation rates for the cercarial and metacer-carial larvae of digenetic trematodes in the snail and crayfish hosts, and the prevalence of Paragonimus westermani among the residents in the vicinity of the stream Namdae, Wyangpi, and Kwang, in the Ulchin county, Kyungpook Province were studied from March to October in 1984. The population density of the snails per square meter of the habitats ranged from 5 to 25, with an average of 15. Among the seven habitats, one, Ducheon, had snails infested with the cercariae of Paragonimus westermani, and the proportion of infested snails was very low, the average being 0.152 per thousand. Of six hundred and four crayfish examined, 113 or 18.7 per cent harboured the encysted larvae of Paragonimus westermani. A high infestation rate for the metacercariae in the crayfish was found in two habitats; 39.0 per cent in the Ducheon and 21. 6 per cent m the Sokwang. The prevalence of Paragonimus westermani among the residents in Ulchin county was relatively high, 25.8 per cent by the Paragonimus intradermal tests, and the difference in the rate of infection between males and females was found to be significant (t>2). The results obtained in this study indicate that endemic foci of Paragonimus westermani exist in Ulchin county and the prevalence of this lung fluke among the residents is relatively high.

• Korean journal of applied entomology
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• v.42 no.4
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• pp.335-343
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• 2003

An experiment was conducted to investigate types of injury inflicted by the stone leek leafminer, Liriomyza chinensis Kato (Diptera: Agromyzidae) on welsh onion. A feeding scar made by an adult female was a hole round in shape, with diameter of 0.08 mm and 0.48 mm in lesion, resulting in a white spot, many of which often form vertical dotted lines on a leaf. Egg spots were oval with 0.1 ${\times}$0.14 mm in size, one or several of which often form a V-shape in group. Feeding by adults began immediately after emergence and was very active from 4th to 5th day. Oviposition was done from 2nd to 6th day after emergence. In both feeding and oviposition, they were more active in the day time. Larvae after emergence crawled up the leaf at first, and then moved up and down to feed on mesophyll. When in high density, they feed on leaf from leaf tip to bottom, and let the leaf die. Area of damage per one larva was calculated as 72.1 $\textrm{mm}^2$. The aged larvae escaped from the leaf in early morning, usually between 5 and 7 am. Most pupation sites were distributed near plants,5cm in soil depth and within 10 cm away from the plant. Pupae of L. chinensis overwintered 10cm below soil surface and emerged from early May to late June the next year Adults then moved to welsh onions near over wintering sites, nursery, transplanted, and levee.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.275-282
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• 2006

Insect pests attacking the leaf of lettuce (Lactuca sativa) were surveyed in environmentally frendly leaf-lettuce-greenhouses in Hwaseong, Namyangju, and Suwon from 2003 to 2004. Sixteen insect species of eleven families in eight orders were collected in greenhouses. Among them, Acyrthosiphon solani, Frankliniella occidentalis, and Autographa nigrisigna were the most serious pest species because of their damage ratio was over 30%. Population of Acyrthosiphon solani showed the highest peak one or two times between mid-April and early June in both the second and the third cropping period. Frankliniella occidentalis reached the highest peak one or two times, the first peak between mid-June and the late July, and the second peak between the mid-August and the mid-October.Autographa nigrisigna reached the highest peak one or times between early June and late July and in the mid-August to late October. The highest peak occurrence of A. solami was observed in early June as many as 4,836 nymphs and adults per 100 leaves. And for F. occidentalis it was in early July occurring 437 larvae and adults per 100 leaves, for A. nigrisigna in early October occurring 42 larvae per 100 leaves. The density of F. occidentalis and its damage as well was greater in soil culture than in hydroponic culture, but in case of both A. solani and A. nigrisigna no such difference between cropping systems was found.

• Journal of Life Science
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• v.28 no.5
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• pp.563-568
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• 2018

The insect industry is a promising agricultural resource and expected to grow steadily. In Korea, Gryllus bimaculatus and the larvae of Tenebrio molior, Protaetia brevitarsis, and Allomyrina dichotoma were listed as general food ingredients. As interest in these edible insects increases, rearing techniques and nutritious food sources are needed for mass production. In this study, wheat bran, dog feed, and pig feed were investigated for their effects on the larval growth of P. brevitarsis and A. dichotoma. When fermented sawdust with 30% wheat bran was used, the larval survival rate of P. brevitarsis and A. dichotoma (p=0.244341 and p=0.007966, respectively) and growth rate (p=0.001400 and p=0.000051, respectively) were significantly lower than those of the control (fermented sawdust with no supplement). Therefore, fermented sawdust with a high density of wheat bran was inappropriate for both insects. When fed fermented sawdust with 2.5 or 5% of dog and pig feed, the survival rate and growth rate of the larvae were higher than those of the control. Interestingly, the maximum larval weight with 2.5% dog feed was increased by $3.35{\pm}0.10g$ and $32.59{\pm}0.79g$ for P. brevitarsis and A. dichotoma, respectively. In addition, the larval period of both was shorter than that of the control by 40 days or more. Therefore, it is considered that animal feed can be used as a feed source for these edible insects.

• Journal of Aquaculture
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• v.16 no.1
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• pp.24-30
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• 2003

Studies of the seed production of Urechis unicinctus were conducted under the laboratory conditions to obtain some information for the U.unicinitus culture. The experiment included developmental studies of the egg development, larval culture, sediment preference and growth of young U.unicinctus. The experiment were conducted from March to August, 2000. The adults of U.unicinctus collected in Namhae-do, Korea. The developments of the fertilized eggs were observed under a light-microscope at intervals of one hour after containing with density of one individual per 1 $m\ell$. The larvae were fed with Phaeodactylum tricornutum cultured at the laboratory. The concentration of the phytoplankton for the feed was 30,000 cells per individual larva. With progress of development, the food concentration was gradually increased, up to 10,000 cells per individual for the young U.unicinctus. Trochophore larvae appeared on the 68 hours after hatching. On the 32 days after hatching, over 50% of fertilized eggs developed into young U.unicinctus. In order to investigate the effect of sediment on the growth and burrowing of U.unicinctus, the young worms were reared in tanks with different grain sizes. The highest value of sediment preference and survival rate of U.unicinctus was shown in the mixture sediment group with below 0.10 mm, 1.01∼12.00 mm, over 3.01 mm and shell. The lowest value in both sediment preference and survival rate of U.unicinctus was observed in 1.0l∼2.00 mm grain size.

• Korean journal of applied entomology
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• v.42 no.2
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• pp.111-118
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• 2003

The population density of the Cotton caterpillar, Palpita indica (Saunder) larvae was gradually increased until 10th October and then decreased rapidly after that time at the watermelon culture of rain sheltered house. After 15th October, many larvae went to soil and molted to pupae for the hibernation. Most of pupae were found in pF 2.4 soil moisture condition, but none in pF 1.5 hydro-morphic soil. Most of the pupae were found below 5cm and there was no pupa below 10cm from the soil surface. The sex ratio of the overwintering pupae was 1.09 : 1.00. For the monitoring of the cotton caterpillar adults using sex pheromone compounds, different mixture ratios of each pheromone compound were investigated with (E)-11-hexadecenal and (E, E)-10,12-hexadecadienal. Seven versus three ratio of (I)-11-hexadecenal and (E, E) -10,12-hexadecadienal was more attractive than any other ratio, and then followed by 6 : 4, 8 : 2, 9 : 1, and 5 : 5 mixtures. As a result of monitoring with 7 : 3 mixture of (E)-11-hexadecenal and (E, E)-10,12-hexadecadienal, occurrence peaks of cotton caterpillar adults showed 4 times per year. The first time of adult appearance was late July in 2000 and middle July in 2001 and the highest number was collected on late September.

• Korean journal of applied entomology
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• v.30 no.3
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• pp.187-195
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• 1991

This study was carried out to acquire some basic biological informations on the granulosis virus (GV) of Pieris rapae and Pieris brassicae. Purified fractions of GV capsules in an sucrose density gradient centrifugation yielded on homogenous and sharp peak without a shoulder. Electron microscopy revealed that GV capsules were mostly ovalglove in shape. P. rapae and P. rapae GV isolated from P. rapae comprised granules($396\pm38\times238\pm25nm$ for P. rapae GV. $375\pm40\times255\pm28nm$ for P. brassicae GV) which contained single virus particle. The virus particles were 250- $275{\times}63$ -73nm for P. rapae GV and 243-250 $\times$ 63-75nm for P. brassicae GV containing a nucleocapsid 225 $\times$ 31nm for P. rapae, 225 $\times$ 29nm for P. brassicae within an envelope. The virulent difference between the two viruses was very small in their virulence for P. rapae larvae showing the $LC_{50}$( -log) with 5.5673 for P. rapae GV and 5.8104 for P. brassicae GV. Also the $LT_{50}$ of the 3rd instar P. rapae larvae against $10^{-6}$ inoculum was 8.17 days for P. rapae GV and 7.16 days for P. brassicae GV.

• Korean journal of applied entomology
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• v.60 no.3
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• pp.323-329
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• 2021

This study investigated the seasonal distribution of ticks in Boeun, Chungbuk, South Korea, from 2016 to 2020. Over the five-year period, ticks were collected annually from four different sites. A total of 17,704 ticks belonging to three tick species (Haemaphysalis longicornis, Haemaphysalis flava, and Ixodes nipponensis) were collected. H. longicornis was the dominant species across all four sites with the highest density of 68.40% of the total collected specimens, followed by H. flava (3.53%) and I. nipponensis (0.06%). The larvae of unidentified species were also collected: 11.81 T.I. (28.01%). The H. longicornis population peaked during the spring season (May-June), whereas the larval population peaked during August and September. H. longicornis was collected the most from four sites (coniferous forest, broad-leaf forest, mountain path, and copse), with the exception of the larvae, which was collected the most in grassland and grave. H. flava was collected from all sites, but in a small proportion. The SFTS virus was not found in any of the 828 pools of ticks during 2016-2020. Based on the results of this study, the continuous surveillance of the tick population is recommended to mitigate the spread of diseases by these vectors.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.355-359
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• 2018

We used the entomopathogenic nematode, Steinernema carpocapsae, for the effective biological control of Lycoriella mali during Agaricus bisporus cultivation. The concentrations of two S. carpocapsae products distributed in Korea were $6{\times}10^4$ and $2.5{\times}10^5m^{-2}$ respectively. As a result of investigating the density of A. bisporus larvae in a rice straw medium and soil in an A. bisporus cultivation house, the mean numbers per $30cm^2$ were 0.8 and 22.2, respectively, and A. bisporus larvae were detected mainly in the soil. The control effects after once spraying S. carpocapsae at $6{\times}10^4$ and $2.5{\times}10^5m^{-2}$ was higher at the 14th day than at the 7th day. Therefore, we investigated the control effect after twice spraying of $6{\times}10^4$ and $2.5{\times}10^5m^{-2}$ at the 14th day. The control effects after this spraying were 51.9% and 96.8%, respectively, and the control effect of spraying at $2.5{\times}10^5m^{-2}$ was better than at $6{\times}10^4m^{-2}$. The control effect of diflubenzuron WP was lower than 50%.