• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.3
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• pp.19-28
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• 2024

The purpose of this study is to investigate the habitat of Luciola unmunsana to understand the status of land snails, which are the larvae prey, and to evaluate the effects of larval feeding preferences and prey size for the restoration of the L. unmunsana habitat as a basis for future restoration projects. The research methods included field surveys of the habitat and laboratory experiments on feeding preferences using three types of land snails (Allopeas clavulinum kyotoense, Euphaedusa fusaniana, Pupinella rufa) observed in the habitat. Field surveys of 13 L. unmunsana habitat sites revealed a total of 24 land snail species. The experimental results regarding the larvae prey were analyzed for statistical significance of feeding preferences using Chi-square tests and independent sample t-tests. Consequently, larvae showed the highest preference for A. c. kyotoense, with statistically significant differences in feeding preferences (p<0.05). Also, statistically significant differences were observed in the size between the land snails that were eaten as prey and those that were not eaten. This research can deepen the understanding of the feeding preferences of L. unmunsana larvae and provide practical guidelines for the effective conservation and restoration strategies of the firefly habitat.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.173-180
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• 2001

The stink bug, Eocanthecona furcellata (Wolff.) is a natural and potential biocontrol agent of Spilarctia obliqua (Walk.). The present investigation reveals the biology, predatory efficiency and reproductive parameters of the predator which feeds on S. obliqua caterpillars in mulberry plantation. In order to find out the role of prey sine on the biology of the predators the predatory insects were separately fed with small and large caterpillars of S. obliqua. The incubation period of the eggs of E. furcellata was 8.37${\pm}$0.44 days, while the nymphal duration varied as per the prey sine. The predator when supplied with small larvae of prey, consumed 61.1 larvae and completed nymphal stage in 19.9 days; while those fed with larger prey, consumed 36.1 larvae and completed their nymphal stage in 21.55 days. The prey size also influences the reproductive parameters of the predator, The adult female predator is more voracious feeder than the adult male and consumed 41.9${\pm}$0.64 small larvae and 42.2${\pm}$0.87 large larvae during their life span. The longevity of male and female was observed as 20.7 and 29.4 days respectively. Visualization of the predator as well as the movement of the prey increases the predatory efficiency. Scanning electron microscopic studies on the feeding part explain its support in effective predation. Field observations indicated a drastic fall in the incidence of the mulberry pest, S. obliqua with the increased population E. furcellata in mulberry plantation.

• Animal cells and systems
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• v.14 no.2
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• pp.125-128
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• 2010

This study investigated the effect of different light intensities on first feeding of chub mackerel Scomber japonicus larvae. Fertilized eggs, obtained from LHRHa-induced spawning of captive broodstock, were stocked (60 larvae/l) into twelve 30-1 aquaria under light intensities of 0, 100, 200, 500 and 1000 lx, with three replicate aquaria per treatment. Temperature was maintained at $20^{\circ}C$ and salinity was 35 psu. Larvae were fed the rotifer Brachionus rotundiformis at a density of five rotifers/ml. Feeding incidence was measured as the percentage of larvae with prey in the digestive tract. Feeding intensity was evaluated as the number of prey in the digestive tract of the larvae. Larvae fed in darkness (0 lx) had significantly lower (P < 0.05) feeding incidence ($13{\pm}0.05%$ larvae with prey) and feeding intensity ($1.00{\pm}0.05$ rotifers per larva) than those larvae fed at 100 ($30{\pm}0.07%$, $1.17{\pm}0.09$ rotifers per larva), 200 ($43{\pm}0.08%$, $1.24{\pm}0.11$ rotifers larvae$^{-1}$), 500 ($53{\pm}0.08%$, $1.48{\pm}0.14$ rotifers per larva) and 1000 lx ($60{\pm}0.08%$, $1.38{\pm}0.13$ rotifers per larva). The feeding incidence of S. japonicus larvae increased with light intensity while feeding intensity showed no significant difference (P > 0.05) between light treatments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.351-358
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• 2016

The aim of this study was to verify the performance of Teleaulax amphioxeia as prey for Brachionus plicatilis and for the larvae of the bivalves (Pacific oyster Crassostrea gigas and Manila clam Ruditapes philippinarum) to select the best of five T. amphioxeia strains. The five strains of T. amphioxeia were collected from the coasts of Korea, purecultured and then fed to the rotifer and bivalve larvae. The density and fecundity rate of the rotifer fed on strain 01 were the highest. The instantaneous growth rate of the rotifer fed strain 08-2 was the highest. The maximum density and fecundity rate of the rotifer fed strain 08-2 were significantly higher than those fed Chlorella ellipsoidea, while instantaneous growth rate showed the opposite pattern. Survival rates of the Manila clam larvae fed each strain of Teleaulax showed no significant difference between strains. Survival rates of the Pacific oyster fed Teleaulax were significantly higher than those fed Chaetoceros sp., but lower than those fed I. galbana. This study indicates that strain 08-2 showed better growth for B. plicatilis and better survival for the bivalve larvae than did the other strains, and that T. amphioxeia can also be used as a prey organism for rotifers or bivalve larvae.

• Journal of Ecology and Environment
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• v.48 no.3
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• pp.214-221
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• 2024

Background: To identify and avoid predators, amphibians rely on chemical cues. Onychodactylus koreanus undergo two to three years of the larval stage in mountainous streams, where they encounter various predators. We aimed to identify the potential predators of O. koreanus larvae based on their antipredator responses to predator odors. Additionally, we examined whether the response was innate or can be strengthened by predator olfactory learning. Results: In Experiment 1, O. koreanus larvae exhibited a substantial antipredator response to Chinese minnow (Rhynchocypris oxycephalus) odor but not to Korean freshwater crayfish (Cambaroides similis) odor. In Experiment 2, O. koreanus larvae, who did not previously expose to R. oxycephalus odor, demonstrated a substantial antipredator response to it. Experiment 3 indicated that predator olfactory learning of R. oxycephalus did not enhance the antipredator response of the larvae. Conclusions: Rhynchocypris oxycephalus could prey on O. koreanus larvae, whose antipredator response to R. oxycephalus odor is innate and not enhanced by olfactory learning. Further investigation into the olfactory system of this species may provide insights into the life cycle of O. koreanus, uncovering hidden underground breeding sites and unknown breeding periods.

• Journal of Korean Society of Forest Science
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• v.9 no.1
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• pp.49-54
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• 1969

As one phase of the biological control of the Pine gall-midge, Thecodiplosis japonensis Uchida et Inouye, this investigation on birds as a vertebrte predator of the larvae of Pine gall-midge was carried out. Species of the birds as predator, number of the larvae as prey for individual birds and seasonal trends of the prey quantity were studied. This work was carried out during the late fall of 1967 and 1968 at Kwang Nueng Forest which is one of the heavily infested districts by the Pine gall-midge. 1. Korean Great-Tit, East China Marsh-Tit, Quelpart Coal-Tit, White-headed Long-tailed Tit, Varied Tit, Kamchatkan Rustic Bunting, Yellow-thrated Bunting, Chestnut Bunting and Korean Goldcrest were found to be the predator of the larvae of Pine gall-midge. 2. The average number of larvae as prey found from individual predator bird species were approximatly 108 for Kamchatkan Rustic Bunting, 17-64 for East China Marsh-Tit, 25-28 for Korean Great Tit and 36 for Quelpart Coal Tit. 3. The seasonal change in the number of the larvae which fell into the ground affected the seasonal trends of the prey quantity of the predator birds 4. Among the 380 birds examined, 157 birds were found to attack the larvae of Pine gall-midge.

• Ecology and Resilient Infrastructure
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• v.5 no.1
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• pp.54-58
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• 2018

Diet composition of amphibians usually reflects the distribution of potential prey within habitats, as well as their diet preference. We identified the diet items of Japanese tree frog (Hyla japonica) using a stomach flushing method in a rice paddy for the establishment of bio-monitoring systems of landscape changes. During the reproductive period, 71% of calling males had empty stomachs. All prey items in the stomachs belonged to the phylum Arthropoda, from eight orders of Insecta and one order of Arachnida. Among insect prey, the most common items in the stomachs were adults of beetles, flies and bugs, and larvae of butterflies and moths. There was a significant positive correlation between the body mass of Japanese tree frogs and the volume of prey items. Our results can provide a basic framework to guide the monitoring systems using prey identification of Japanese tree frogs.

• Animal Systematics, Evolution and Diversity
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• v.28 no.1
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• pp.36-41
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• 2012

The larvae of Chaoborus are widely distributed in lakes, ponds, and reservoirs. These omnivorous Chaoborus larvae are crucial predators and play a role in structuring zooplankton communities, especially for small-sized prey. Larvae of Chaoborus are commonly known to produce predator-induced polyphenism in Daphnia sp. Nevertheless, their taxonomy and molecular phylogeny are very poorly understood. As a fundamental study for understanding the role of Chaoborus in predator-prey interactions in a freshwater ecosystem, the molecular identification and phylogenetic relationship of Chaoborus were analyzed in this study. A molecular comparison based on partial mitochondrial cytochrome oxidase I (COI) between species in Chaoborus was carried out for the identification of Chaoborus larvae collected from 2 localities in Korea. According to the results, the Chaoborus species examined here was identified as C. flavicans, which is a lake-dwelling species. Furthermore, partial mitochondrial genome including COI, COII, ATP6, ATP8, COIII, and ND3 were also newly sequenced from the species and concatenated 5 gene sequences excluding ATP8 with another 9 dipteran species were compared to examine phylogenetic relationships of C. flavicans. The results suggested that Chaoborus was more related to the Ceratopogonidae than to the Culicidae. Further analysis based on complete mitochondrial DNA sequences and nuclear gene sequences will provide a more robust validation of the phylogenetic relationships of Chaoborus within dipteran lineages.

• Ocean and Polar Research
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• v.39 no.4
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• pp.257-267
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• 2017

Although Pacific mackerel (Scomber japonicus) is an important commercial species in Korea, its recruitment mechanism remains largely unknown. Diel vertical positioning of larvae in the water column, which is affected by their specific gravity and the surrounding water density, may help to provide an understanding on recruitment success through predator avoidance and prey availability. The specific gravity measurement on Pacific mackerel eggs and larvae would seem to be essential information necessary to learn about the transport process from spawning to nursery grounds, and consequently the recruitment success. Eggs were artificially fertilized, and larvae were fed with rotifer when their mouths opened 3-4 days after hatching. We conducted the experiment using a density gradient water column to measure the ontogenetic changes in specific gravity from fertilization to 10 days after hatching. Egg specific gravity was stable during most of the embryonic period, but a sudden increase to $1.0249g\;cm^{-3}$ happened just before hatching. However, the specific gravity of newly hatched larvae was much lighter ($1.0195g\;cm^{-3}$), and specific gravity tended to increase continuously after hatching. Comparison of specific gravity with seawater density reveals that eggs and newly hatched larvae can float in the surface layer of the ocean. For the later period of the experiment, the specific gravity showed a cyclic diel pattern: the highest in the evening while the lowest at dawn. The fullness of larval stomach may be responsible for the observed differences in specific gravity, because stomach fullness was lower (40-60%) at midnight, and higher (80-85%) in evening. The diel pattern of specific gravity might provide clues regarding how larvae match the diel vertical migration of prey organisms.

• Korean journal of applied entomology
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• v.35 no.2
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• pp.126-131
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• 1996

These experiments were conducted in the laboratory conditions to determine the prey consumption of a predaciousphytoseiid mite, Amblyseius womersleyi Schicha, and its ability to regulate the population of tea redspider mite, Tetranychus kanzawai Kishida. The functional response curve of the adult A. womersleyi to thedensity of eggs, larvae, and nymphs of T. kanzawai indicated Holling's Type 11: the consumption of prey bythe adult A. womersleyi increased with the prey density but the consumption rate decreased. The critical initialratio to suppress the prey population by the predator seemed to be 32:l @rey:predator) at 25"C, and 16:l at20$^{\circ}$C on kidney bean plant. The predator could not regulate any initial ratio of the prey population at 15$^{\circ}$C.^{\circ}$C.