• Journal of Photoscience
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• v.9 no.2
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• pp.243-245
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• 2002

Pigment-dispersing factor (PDF) is an octadecapeptide distributed in the optic lobe and the brain in a variety of insect species. There are lines of evidence suggesting possible involvement of PDF in the insect circadian system. However, its physiological roles in the circadian time keeping mechanism have not been clearly defined. In this study, we have examined the phase shifting effects of Gryllus-PDF on the circadian locomotor rhythm in the cricket Gryllus bimaculatus of which circadian clock is located in the optic lobe. Phase shifts in the circadian activity rhythm were measured following microinjection of 22nl of vehicle (Ringer's solution) or O.lmM PDF into the optic lobe through the compound eye at various circadian times. The results showed that PDF induced phase shifts of the circadian clock in a phase-dependent manner, suggesting that it may play a role as an input signal for the circadian clock.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.67-74
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• 2013

This research was conducted to investigate the competition for survival between the two cricket species: Gryllus bimaculatus (GB) and Teleogryllus emma (TE). The test insects for this research were bred in the greenhouse of the Ecological Entomology Lab, College of Agriculture and Biosciences, Kyungpook National University, Korea. The feeding environment was $28^{\circ}C$ to $30^{\circ}C$, Long-Day condition (16L : 8D) and Relative Humidity: 50%~60%. The changes of the individual number in two species (TE, GB) were checked every day. This research had three experimental conditions which the ratios of individuals (TE : GB) were set at 1 : 2, 1 : 1 and 2 : 1. The survival rate of GB was net better than that of TE in the result of this study. However, due to the absence of the diapauses period in the egg stage, GB would dominate over TE in the field condition. The appropriate legal measure against GB is recommended.

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.2
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• pp.115-125
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• 2022

In this study, we investigated the developmental characteristics and genetic diversity of seven populations of two-spotted crickets (Gryllus bimaculatus De Geer, 1773 (Orthoptera: Gryllidae)) raised in South Korea. Regarding the developmental characteristics of the species, we observed no statistically significant difference in the weight of the nymphs in the six populations we tested. After molting, although weight differences were observed between the populations in each stage of the developmental period, the average weight for each developmental stage was constant. We also analyzed mitochondrial COI gene sequences (DNA barcoding region) of the reared crickets collected from five insect farms and two national insect rearing facilities and the resultant sequences were analyzed together with the 12 sequences from foreign countries specimens obtained from public data. We detected six haplotypes from 111 specimens, indicating a low intraspecific genetic distance (~1.8%). The most dominant haplotype was overwhelmingly haplotype 1, which was found in all South Korean specimens and four specimens from China, Indonesia, and Germany. These findings indicate that the low genetic diversity of South Korean specimens can be explained by the fact that the G. bimaculatus population imported for feed from Japan in the early 2000s became a maternal group that spread throughout cricket farms in South Korea. In order to breed healthy cricket strains, it is necessary to increase genetic diversity by importing them from other countries through appropriate quarantine procedures.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.04a
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• pp.80-80
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• 2003

The isolation and purification of ferritin from the cricket, Gryllus bimaculatus haemolymph were accomplished by anion exchange column chromatography using HiTrap Q column (1.6 $\times$ 4 cm, Amersham Phamacia Co.), 7$0^{\circ}C$ heat and acid treatment, and gel filtration column chromatography using G4000SW column (0.75 $\times$ 60cm, TOSOH Co.) by FPLC system. (omitted)

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.05a
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• pp.169-169
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• 2002

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.05a
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• pp.170-170
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• 2002

• Korean Journal of Clinical Laboratory Science
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• v.36 no.2
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• pp.258-268
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• 2004

This study was carried out to investigate preventive effects of extracts of cricket, Gryllus bimaculatus, against the 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD)-induced toxicity in 7-week-old Sprague-Dawley male rats. Thirty five male rats were divided into 5 groups: one normal control group treated with vehicle and saline (G1); one TCDD-treated group by single intraperitoneal injection (G2); three preventive groups (G3, G4, and G5). The last three groups, G3, G4, and G5, were fed on cricket extracts (50, 100, and 200 mg/kg, respectively) for 2 weeks before TCDD treatment. Various harmful effects were shown by TCDD treatment. The body weights of rats were lost by TCDD. In addition, severe hypertrophy and color change, and the weights gaining were found in the livers of TCDD-treated rats. It was observed that the cytoplasmic vacuolizations and inflammatory cell infiltration around portal triad in the liver. TCDD also elevated the serum activity levels of alanine transaminase(ALT) and aspartate transaminase(AST). However, those losses were compensated by cricket extracts treatment at the level of 200 mg/kg. These findings indicate that cricket extracts may have protective effects against TCDD-induced toxicities in rats.

• Animal Bioscience
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• v.36 no.9
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• pp.1384-1392
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• 2023

Objective: Replacing soybean meal (SBM) with cricket (Gryllus bimaculatus) meal pellets (CMP) in concentrate diets was investigated for feed efficiency, ruminal fermentation and microbial protein synthesis in Thai native beef cattle. Methods: Four male beef cattle were randomly assigned to treatments using a 4×4 Latin square design with four levels of SBM replaced by CMP at 0%, 33%, 67%, and 100% in concentrate diets. Results: Results revealed that replacement of SBM with CMP did not affect dry matter (DM) consumption, while digestibilities of crude protein, acid detergent fiber and neutral detergent fiber were significantly enhanced (p<0.05) but did not alter digestibility of DM and organic matter. Increasing levels of CMP up to 100% in concentrate diets increased ruminal ammoniacal nitrogen (NH₃-N) concentrations, blood urea nitrogen, total volatile fatty acids and propionate concentration (p<0.05), whereas production of methane and protozoal populations decreased (p<0.05). Efficiency of microbial nitrogen protein synthesis increased when SBM was replaced with CMP. Conclusion: Substitution of SBM with CMP in the feed concentrate mixture at up to 100% resulted in enhanced nutrient digestibility and rumen fermentation efficiency, with increased volatile fatty acids production, especially propionate and microbial protein synthesis, while decreasing protozoal populations and mitigating rumen methane production in Thai native beef cattle fed a rice straw-based diet.

• Food Science and Preservation
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• v.31 no.1
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• pp.80-98
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• 2024

Edible insects, such as the two-spotted cricket (Gryllus bimaculatus, GB), have high nutritional value but are not widely consumed because of their appearance and smell. Consequently, the development of foods containing these insects in less recognizable forms, e.g., flour-like powders, has drawn considerable attention. Herein, we investigated the quality characteristics of muffins prepared from wheat flower supplemented with fresh ginseng (5%) and GB (0, 10, 20, and 40%) powders. GB loading was negatively correlated with muffin volume, height, moisture content, and textural properties (hardness, springiness, cohesiveness, and chewiness) and positively correlated with crude protein content and antioxidant properties. Significant (p<0.05) color differences were observed between samples with different GB loadings. The contents of hexanal and nonanal, which are the major volatiles responsible for off-flavor, increased with increasing GB loading, and the number of volatiles maximized at 40% GB. Sensory preference decreased in the order of 0% GB>10% GB≈ 20% GB>40% GB. Based on these results, a GB loading of 20% offered the best trade-off between attractiveness and nutritional value. Thus, this study promotes the widespread use of GB in the food industry and the development of various edible-insect-based food products.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.121-121
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• 2003