• Journal of Microbiology
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• v.43 no.5
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• pp.463-468
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• 2005

Studying the bacteria of hazardous insects allows the opportunity to find potentially better biological control agents. Therefore, in this study, bacteria from summer chafer (Amphimallon solstitiale L., Coleoptera: Scarabaeidae) we isolated and identified the insecticidal effects of bacteria isolated from A. solstitiale and Melolontha melolontha L. (common cockchafer, Coleoptera: Scarabaeidae) and the mixtures of these bacterial isolates were investigated on A. solstitiale larvae. Crystals from Bacillus sp. isolated from M. melolontha were also purified, and tested against the second and third-stage larvae of A. solstitiale. The bacterial isolates of A. solstitiale were identified as Pseudomonas sp., Pseudomonas sp., Bacillus cereus and Micrococcus luteus, based on their morphology, spore formation, nutritional features, and physiological and biochemical characteristics. The insecticidal effects of the bacterial isolates determined on the larvae of A. solstitiale were $90\%$ with B. cereus isolated from A. solstitiale, and $75\%$ with B. cereus, B. sphaericus and B. thuringiensis isolated from M. melolontha within ten days. The highest insecticidal effects of the mixed infections on the larvae of A. solstitiale were $100\%$ both with B. cereus+B. sphaericus and with B. cereus+B. thuringiensis. In the crystal protein bioassays, the highest insecticidal effect was $65\%$ with crystals of B. thuringiensis and B. sphaericus isolated from M. melolontha within seven days. Finally, our results showed that the mixed infections could be utilized as microbial control agents, as they have a $100\%$ insecticidal effect on the larvae of A. solstitiale.

• Korean journal of applied entomology
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• v.30 no.4
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• pp.265-270
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• 1991

Oviposition activities of the larger black chafer(HolotTichia mOTosa Waterhouse) and Korean black chafer(H. diomphalia Bates) were examined in the laboratory and field from 1985 to 1990. In H. mOTosa and H. diomphalia, total durations of oviposition were 31.70$\pm$17.33 days and 61.17$\pm$23.15 days, numbers of days of actual oviposition were 9.00$\pm$5.03 days and 22.33 $\pm$11.72 days, total numbers of eggs laid laid per female were 23.43$\pm$16.26 and 65.67$\pm$37.97, and numbers of eggs laid per female per day were 2.60$\pm$2.50 and 2.94$\pm$2.34, under laboratory conditions. Difference of total numbers of eggs per female between both species seemed to be due mainly to numbers of days of actual oviposition. Oviposition period under laboratory conditions was considerably delayed behind that in the field in H. morosa but the two oviposition periods were almost overlapped in H. diomphalia. In the field, rates of gravid females of H. diomphalia were obviously higher than those of H. mOTosa, but numbers of eggs per gravid female were almost same in the two species, H. diomphalia adults did not show marked oviposition and feeding preference among several species of weed plants in the insect net chamber.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.37-41
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• 1991

Laboratory experiments were conducted to examine the effects of soil moisture on the survival of the larger black chafer(Holotrichia morosa Waterhouse) eggs and larvae. Survival rates of eggs and 1st, 2nd, and 3rd instar larvae were all above 79% at soil moisture of 15% and 25% in sandy loam and clay loam soil, but decreased considerably at 5% and 35%. At these extreme moistures there seem to be differences in survival rates of eggs and larvae between soil textures. Egg development was delayed as soil moisture approached to the lower limit for survival. Older eggs were tolerant to the high moisture stress(33-36 % , clay loam soil), and duration of the stress affected egg development. Feeding of 3rd instar larvae was obviously suppressed at the higher level of soil moisture.

• The Korean Journal of Mycology
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• v.52 no.2
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• pp.125-134
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• 2024

A fungal strain, KNUF-4H-A belonging to the genus Phaeosphaeria was isolated from the citrus flower chafer (Gametis jucunda) in Chungcheongbuk-do, Korea. This strain was further identified as Phaeosphaeria chengduensis through phylogenetic analyses based on a concatenated dataset of DNA sequences of internal transcribed spacer (ITS) regions, as well as the small subunit rDNA (SSU), large subunit rDNA (LSU), RNA polymerase II second largest subunit (RPB2), and translation elongation factor 1-α (TEF1-α) genes. The isolate KNUF-4H-A exhibited typical cultural characteristics of P. chengduensis, producing colonies that were flattened, greenish-grey at the edges, grey-white at the center, and dark brown on the reverse side. Phaeosphaeria species have been reported in various ecosystems, including terrestrial and freshwater environments. The isolation of KNUF-4H-A from the citrus flower chafer provides valuable insights into the habitat diversity of Phaeosphaeria. This is the first record of Phaeosphaeria chengduensis in Korea.

• Korean journal of applied entomology
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• v.58 no.2
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• pp.159-164
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• 2019

The purpose of this study was to investigate whether leaf damage in pear orchards caused by large black chafer beetles can be controlled through net traps and clove oil treatment. In June 2017, we measured large black chafer beetle population density and leaf damage rates in two orchards, located in Boseong and Hampyeong, under three treatments: net, net plus clove oil, and control. In order to evaluate the effect of net position on the adult beetles, nets were placed outside the orchard and along the upper and lower parts of a horizontal trellis. The adult beetle population density was 20.4 to 34.7% lower in the net alone treatment, and 21.1 to 38.1% lower in the combined net and clove oil treatment than in the control. The adult beetle population density was 10.9-14.4 times higher outside the orchard and 5.1 to 9.1 times higher in the upper parts of the horizontal trellis than in the lower parts of the horizontal trellis. Leaf damage under both the net only and net plus clove oil treatments was significantly lower than that in the control at both sites. Therefore, intensive net installation around orchards may be a practical organic alternative to prevent leaf damage caused by large black chafer beetles.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.85-91
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• 2016

Exosomes are homogenous vesicles of 40-100 nm diameter produced endogenously. Exosomes are generated by inward budding into multi-vesicular bodies (MVB) and then released to extracellular space. Exosomes contain various nucleic acid and protein cargoes from their cells of origin and this endosomal cellular molecules are used for intracellular communication and for both promotion and suppression of immune responses. Recently, they are also considered as delivery vehicle for therapeutic proteins due to their characteristics of stability in body fluids and ability for target uptake. Also, they show less immune reactivity because the isolated exosome harboring therapeutic proteins can be from the same host. White-spotted flower chafer, Protaetia brevitarsis is one of the major insect commercially reared in Korea. There are bacterial and fungal pathogens causing diseases in the beetle, and these diseases incur economic loss to the larva-rearing farms. Due to their endosomal cargoes, exosomes are good candidates in use of disease diagnosis. In this study, we isolated insect exosome from the hemolymph of P. brevitarsis, and verified it by analysis of the exosome-specific surface proteins and RNA.

• Korean Journal of Organic Agriculture
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• v.26 no.2
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• pp.245-257
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• 2018

The efficacy of different control techniques against the large black chafer, Holotrichia parallela Motschulsky (Coleoptera: Scarabaeidae), in organic pear (Pyrus pyrifolia) orchards was evaluated. In this study, field trials were conducted in three locations in Korea-Naju, Hampyeong, and Boseong-to evaluate different techniques to suppress these beetles. Pheromone traps, bio-insecticides (Hongmengye and Melchungdaejang), and a combination of the two were applied as treatments. In Naju, Hampyeong, and Boseong, the highest number of adult H. parallela were caught in the control plots (n=45, n=39, and n=20, respectively), while the fewest were caught in the pheromone plus bio-insecticide plot (n=19) in Naju and in the combined treatment plot in Hampyeong (n=10). In Naju, the greatest leaf damage was observed in the control (66%), and in all locations (Naju, Boseong, and Hampyeong), the least damage occurred in the combined treatment plots (42%, 36%, and 24%, respectively). Regarding the tree canopy, the greatest leaf damage was observed in the upper canopy, and less damage was observed in the lower canopy. These results demonstrate that the combination of sex pheromone traps and bio-insecticides can be used to manage H. parallela in organic pear orchards.

• International Journal of Industrial Entomology and Biomaterials
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• v.31 no.2
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• pp.75-78
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• 2015

The white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae), is an economically important insect in Korea. Traditionally, it has been regarded as a medicine for preventing liver-related diseases and suppressing liver cancer. Recently, this beetle was enlisted as a temporal food ingredient by Korean Ministry of Food and Drug Safety. Therefore, this beetle is focused as a one of the important insects that are commercially reared and sold in Korea. As the economic importance of this beetle is growing, the suitable rearing conditions are needed for more detailed investigation. In this study, we compared three temperature conditions and two food additives, rice chaff and soybean cake, for its effects on the body weight change of third instar larvae of P. brevitarsis. Temperature is a major environmental factor that has tremendous effects on rearing insects. In additions, rice chaff and soybean cake are byproducts of other agricultural activities. Therefore, it is easy to get, and the price is comparatively low. However, they still have meaningful amount of nutrients. With four different kinds of feed and three temperature conditions on the third instar larvae of beetles, the body weight change was tracked for 14 wk. We concluded that 27.5℃ is the optimal temperature to rear the third instar larvae among three temperatures (25, 27.5, and 30℃). Among four different feeds, conventional fermented oak saw dust with rice chaff and soybean cake was the best feed for larval weight gain during 14 wk. However, feed with soybean cake at 30 ℃ was the best condition for rearing P. brevitarsis larvae when temperatures and feeds were compared at the same time.

• Korean journal of applied entomology
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• v.29 no.4
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• pp.222-229
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• 1990

The flight activities of Holotrichia morosa Watershouse and H. diomphaia Bates adults were monitored by blacklight traps for six years from 1984 to 1989. The flight activity of H. morosa adults was most prominent from late June to early August with a peak flight in mid July, and that of H. diomphalia adults mainly occurred from early May to late June of odd years with the peak flight dates varying year by year. The flight activities of the two species during the fight period became vigorous after moderate to heavy rainfalls. The overwintered adults of H. diomphalia seemed to begin flying when the daily mean temperature rose above $15^{\circ}C$. The ratios of the females to the total adults collected by the blacklight traps were 53.3% for H. morosa and 0% for H. diomphalia, although the female sex ratio of the latter species was 57.4% in the field.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.813-830
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• 2020

In this study, the potential of infrared assisted freeze-drying (IRAFD) was tested for the production of shelf-stable edible insects: Protaetia brevitarsis larva (larva of white-spotted flower chafer). The IRAFD system was customized using an infrared lamp, K-type thermocouple, controller, and data acquisition system. The infrared lamp provided the sublimation energy for rapid freeze-drying (FD). The IRAFD conditions were continuous IRAFD-5.0 kW/㎡ and IRAFD-5.0 kW/㎡ at different weight reduction (WR) (10%, 20%, and 30%). The continuous IRAFD reduced the drying time to 247 min compared to the 2,833 min duration of FD (p<0.05). The electrical energy could be reduced by more than 90% through infrared radiation during FD (p<0.05). The Page model resulted in the best prediction among the tested drying kinetic models. In terms of quality, IRAFD showed significantly lower hardness, chewiness, and higher protein levels than hot air drying and FD (p<0.05). IRAFD better preserved the glutamic acid (6.30-7.29 g/100 g) and proline (3.84-5.54 g/100 g). The external product appearance after IRAFD exhibited more air pockets and volume expansion, which might result in a good consumer appeal. In conclusion, this study reports the potential of IRAFD in producing shelf-stable and value-added edible insects.