• Korean journal of applied entomology
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• v.3
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• pp.15-19
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• 1964

1. The heat output by the insects, Oryzaephilus surinamensis, Tribolium confusum, Sitophilus zeamais and Sitophilus granarius, was investigated by reading the temperature of the inside of the grain in which the insects were developing in 2 Ib or 7 Ib jars incubated at $25^{\circ}C\; and\; 70\%$ R.H. 2. All the insects tested increase the temperature of grain, but the amount of heat produced by insects varies with the species of and the developmental stages of the insects. 3. It was found that all the temperature peaks correspond with the peak in number of the fourth instar larvae and the period in which the insects start to cause the heating corresponds to its 1 st and 2nd instar larvae. 4. Sitophilus spp. whose larvae live in the endosperm of the wheat produced more heat than Tribolium confusum and Oryzaephilus surinamensis whose larvae live on the grain. 5. Among the four species of insects, Sitophilus zeamais Produces the highest heat, followed by Sitophilus granarius, Tribolium confusum and Oryzaephilus surinamensis. 6. It is considered from the above results that the heat produced by insects seems to depend upon the species, the number and the age structure of population, and its its surroundings. 7. It is suggested therefore that when comparing the rate of development of insects kept at different densities. the effects caused by heating at the higher densities must be considered.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.206-216
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• 2018

We analyzed the effects of spatio-temporal variation in the leaf production of oaks on the density and species richness of herbivores, as well as the consumption by herbivores in the east coastal region of Korea, which is an area that has been damaged by forest fires. The main herbivore that feeds on oak leaves was moth larvae. In mid-August the insect larvae showed the highest density and species richness. Approximately 60.5% of total plant-eating insect larvae were present from August to September 2011. Oak leaf production was at its peak from July to August, and the peak damage caused by herbivores was from August to September. Depending on the investigation timing and site of the survey, oak leaf production, larval densities, and species richness showed large variations. The average production of oak leaves between July and August was estimated to be $0.96ton\;ha^{-1}$. The production of oak leaves during this period also showed spatial variations ranging from 0.34 to $1.89ton\;ha^{-1}$. In August, the consumption of oak leaves by the herbivores showed spatial variations ranging from 0.15 to $1.51ton\;ha^{-1}$. Where oak leaves had a higher yield, they tended to increase in density and species richness of the herbivores. As the production of oak leaves increased, so did the overall consumption and consumption rate by the herbivores. This means that the production of oak leaves is highly related to time and space, and there is a concentration response in which the new individuals gather. Research into the spatio-temporal heterogeneity of the food sources and their effects on the higher levels of the food web can help us quantitatively understand and evaluate the structure and functions of the burnt ecosystem that is caused by forest fires.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.147-152
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• 2015

The seasonal pattern of larvae, nymph and adult life stages for three tick species were studied for April-October, 2014. Haemaphysalis longicornis (610), Haemaphysalis flava (296) and Ixodes nipponensis (15) were collected from Pocheon by the dragging and flagging method. H.longicornis (254), H.flava (345) and I.nipponensis (15) were collected from Cheolwon in the same way. H.longicornis adults peaked in June while nymphs were more frequently collected from April through June. In contrast, H.longicornis larvae were collected only in September and October. H.flava adults were collected in April, September, and October while nymphs were collected from April through October. The nymphs peaked in April in Pocheon while May was the peak in Cheolwon. Larvae of H.longicornis and H.flava were collected only in September and October. I.nipponensis adults and nymphs were more frequently collected in April, while the larvae were not collected during that period. Collecting ticks by the dragging and flagging method provides estimates of population densities for life stages of the selected species and the associated disease risk. These results can be used to predict seasonal population densities of ticks and the prevalence of tick-borne pathogens.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.349-356
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• 2012

Eicosanoid mediates various cellular immune responses in insects. This study aimed to discover its novel action on the modulation of hemocyte populations in response to an immune challenge. Upon bacterial challenge, the last instar larvae of the beet armyworm, Spodoptera exigua, increased their total hemocyte density in 2 h, and then decreased it to a basal hemocyte density level. This rapid increase in total hemocyte density was explained by an increase of plasmatocyte and spherulocyte densities. When larvae were treated with dexamethasone (a specific phospholipase $A_2$ ($PLA_2$) inhibitor), they did not show any increase in hemocyte density in response to bacterial challenge. However, the addition of arachidonic acid (a catalytic product of $PLA_2$) to larvae treated with dexamethasone recovered the up-regulation of hemocyte density in response to bacterial infection. Among eicosanoid, cyclooxygenase (COX), but not lipoxygenase (LOX), products seemed to mediate the increase of hemocyte density in response to bacterial infection because naproxene (a COX inhibitor) inhibited the hemocyte density increase, though esculetin (a LOX inhibitor) did not. Prostaglandin $E_2$, a COX product, significantly increased the hemocyte density even without bacterial infection. These results suggest that eicosaniod mediates a rapid increase in total hemocyte density in response to immune challenge.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.123-139
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• 1985

The present survey was undertaken to observe the geographical distibution of matacercaria among the sweetfish, Plecoglossus altivelis, the most important second intermediate host of Metagonimus yokegawai, which were collected during the period from 1983 to 1984 in south-eastern coastal areas of Korea. The results obtained were summarized as follow: 1. A total of 668 sweetfish collected from 70 chins (=streams) in the above coastal arcus was examined for the metacercariae, and 432 (64.7%) among them were infected with metacercariae of M. yokogawai. The mean number of metacercariae in a fish was in the range from 0 to 29,604 and the mean number of the metacercariae in a fish was 640.3. 2. It was observed that the mean infection rate showed 46.45 in Gangweon-Do (=province) . The infection rates varied from stream to stress showing 100% in Namdae stream(Gangnun-city) , Obsib stream (Samchok-gun) and Dongmak, 95.0% in Hosan stream, 90.0% in Gungchin stream, and Namdae stream (Yangyang-fp) ,80.0% in Hwasang stream,50.0% in Daebong stream,45.0% in Yonghwa stream, 30.0% in sangchsn stream and Sachsn stream, 20.0% in Munam stream and Okgyoe stream, 15.0% in Imweon stream, 10.0% in Namchsn stream. And no metacercarial infections in their fish host were found in the areas of Mulchi stream, Sangun stream, Gosamun stream, Jonchon stream and Gagok stream. 3. It was observed that the mean infection rate showed 50.9% in Kyangsangbuk-Do (=province). The infection rates also varied from stream to stream showing 100% in Songchon stream, Osib stream (Yongdok-gun) and Daejong stream,60.0% in Pyanghae stream and Gunmu stream,50.0% in Buhwung stream and stream, 25.0% in Nagok stream, 20.0% in Oangbi stream, 10.0% in Namhodong stream. And no metacercarial infections in their fish host were found in the areas of Namdae stream (Uljinup) and Chaksan stream. 4. It was observed that the mean infection rate showed 67.6% in Kyangsangnam-Do(=province). The infection rates varied from stream to stream showing 100% in Taehwa river, Hwiya river, Inchfn stream, Miryang river, Nam river, Hwagae stream, Koha stream, Sosang stream, and Tongchon stream,90.9% in Yancho stream,90.0% in Hoihwa stream,80.0% in Chindong stream, 66. YoA in Chingyo stream, 40.0% in Hoyam river. And no metacercarial infections in their fish host were found in the areas of Chinjon stream, Sanchan stream and Jukch6n stream. 5. It was observed that the mean infection rate showed 94.6"A in 0h511anam-Do(=province). The infection rates varied from stream to stream showing 100% in DongchEn stream, Isachon stream, Somjin river(GoksEng-gun) , Ssmjin river(Kurye-gun) , S6si stream, Gokchsn stream, Kohung stream, Kwansan stream, Youi stream, stream, Unj6n stream and Apnae stream, 92.3% in Tamjin river, 90.9% in Okkok stream, 84.6% in Songgen stream. And no metacercarial infections in their fish host were found in the area of Ypmgpl stream. 6. On the other hand, the infection rate showed 100% in Inchsn river of Chollabuk Do (=province) (=province) and Kangsn stream of Cheju-Do(=province) .

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.195-200
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• 2004

The occurrence pattern and bionomics of Selatosomus puncticollis (Motschulsky) were surveyed in three net house (6$\times$70m) in the field and in a laboratory ($20^{\circ}C$, RH$75\%$, L16/DB). Emergence of hibernated adults of S. puncricollis started from early May, reached peak at early June and diminished in late June. Occurrence rate to total number was $42.1\%$ in early June and $31.7\%$ in late May, when most of hibernated adults emerged at these periods. Adults started to oviposit from mid June, and eggs hatched from early July Larvae turned into pupae from mid July and emerged to adults from mid August. Egg-period was 23 days and pupal period was 21 days. It is estimated that preovipositional period and larval period were approximately 10 months and 30 months, respectively. Wireworms were distributed at the soil depth of 10-5 cm, $56.8\%$ in 1997 and $45.8\%$ in 1998. To establish bait techniques to attract wireworms in the soil, six baits: pieces of potato, carrot, and sweet potato, wheat grains, corns, and flour dough wrapped with gauze, were buried at 15 cm of soil depth, and collected after 5 and 10 days. The numbers of wireworms attracted by potato pieces, wheat grains and sweet potato pieces after 10 days were 1.8, 1.6, and 1.4/bait, respectively. Therefore, burying potato pieces at 15 cm of soil depth and collected after 10 days could be recommended as a wireworm baiting technique.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.50-55
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• 2000

Occurrence, Injury aspects and control effect of some chemicals were investigated on tomato in plastic house from 1997 to 1998. Adults trapped by yellow sticky trap and sweeping net were increased from late May abruptly. Survey of population densities by yellow sticky trap was more clear than sweeping net. Damaged leaves were found out all the year round in continuous cropping fields and rate of damaged leaves was below 20% in early April and increased gradually up to 80% level after late May. Otherwise, damaged leaves were appeared from 6 weeks after transplanting in first growing field and then damaged leaves was 80% level in spring culture. In autumn culture, rate of damaged leaves was maintained 80% level from transplanting to harvesting date regardless of cultivation years. Number of adults was trapped from late May and peak was late June but mature larva was $6{\sim}8$ individuals in spring culture. In autumn culture, adult and larval densities was maintained high for 3 weeks after transplanting but begun to decrease from 4 weeks(early September). Chlorfenapyr EC, cyromazine WP and abamectin EC could suppress larval populations of Liriomyza trifolii effectively.

• Research in Plant Disease
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• v.25 no.3
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• pp.124-130
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• 2019

The study was conducted to investigate the infestation and distribution of plant-parasitic nematodes on Chinese yam (Dioscorea batatas) in Andong, Korea. Root-knot nematodes, Meloidogyne incognita was the most prevalent nematode species which is found from 43 yam fields (81.1%) with high population densities (average of 450 juveniles/$300cm^3$). Other nematodes, root-lesion nematode (Pratylenchus spp.) and pin nematode (Paratylenchus spp.) were less problematic. Density of juveniles (J2) of M. incognita was $10\;J2/300cm^3$ by August, then increased to 274 in September and 624 in October. The highest J2 density was found at the soil depth between 40 and 50 cm ($1,840\;J2/300cm^3$). M. incognita was able to infest yam tuber down to a depth of 70 cm and developed galls outside and brown spots inside. The highest number of females were found at 40-50 cm (79 females/10 cm piece) tuber from the top.

• Journal of the Korean Geosynthetics Society
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• v.4 no.2
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• pp.19-28
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• 2005

This paper presents a laboratory investigation on the failure mechanism of geosynthetic reinforced slopes using 1/5-scale reduced model. The components of the model were selected with due consideration of the similitude law and the step-by-step actual wall construction procedure was closely simulated. The model tests successfully replicated the failure mechanism with relative density, slope and vertical spacing.

• Journal of Life Science
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• v.31 no.5
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• pp.475-480
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• 2021

Interest in edible insects such as Protaetia brevitarsis has increased rapidly, and several insect producers use these insects in industrialized mass production. However, mass rearing of insects can cause insect diseases. Sprouted barley is a valuable source of nutrients and has antioxidant, antimicrobial, anti-inflammatory, and anti-cancer effects. This study was conducted to investigate the effect of sprouted barley as a feed additive for producing healthy P. brevitarsis larvae. P. brevitarsis larvae were fed feeds with or without sprouted barley, and their body weight and larval period wewe checked weekly. To confirm the antibacterial effects of sprouted barley, in vitro bioassays were performed by counting Serratia marcescens colonies, and in vivo bioassays were performed by determining the survival rate and body weights of the S. marcescens-infected larvae. Larvae fed different feeds were analyzed for their nutrient compositions (i.e., such as proximate composition, minerals, amino acids, and heavy metals). Larvae fed 5% and 10% sprouted barley had maximum weight increases of 19.2% and 23.1%, respectively. Both treatment groups had significantly shorter larval periods than those of the control group. Sprouted barley markedly inhibited the growth of entomopathogenic S. marcescens. Furthermore, larvae fed sprouted barley exhibited higher Cu, Zn, and K levels. Seventeen amino acids were present in larvae fed sprouted barley, of which, tyrosine and glutamic acid were predominant. No heavy metals were detected in any of the investigated groups. Therefore, sprouted barley may be a suitable feed additive for producing high-quality P. brevitarsis larvae.