• Journal of Life Science
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• v.27 no.3
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• pp.334-338
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• 2017

In this study, the nutritional components of Tenebrio molitor, Protaetia brevitarsis, and Allomyrina dichotoma larvae, which have been registered as novel foods, were analyzed and compared to expand the diversity of selection criteria for edible insects. The contents of crude components, amino acids, fatty acids, and minerals were analyzed. According to the results of comparative analysis of edible insects, crude proteins were abundant in all three kinds of insects. The content of crude fat was the highest in T. molitor, and the content of carbohydrate was the highest in A. dichotoma. When comparing the composition of amino acids, total amino acid content and essential amino acids were the highest in T. molitor larvae. In T. molitor and P. brevitarsis larvae, the compositions of fatty acids were similar, with higher amounts of unsaturated fatty acids than in A. dichotoma. In terms of mineral content, A. dichotoma contained the highest amounts of calcium and iron, whereas P. brevitarsis contained the highest amounts of phosphorus and potassium. With these results, it is expected that edible insects could be selected according to nutritional demand. In addition, multiple combinations of edible insects will offer a richer intake of nutrients.

• 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.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.65-70
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• 2003

For the purpose of the protection of beneficial insects from pathogens and the development of control agent against pests, a strain of Metarhizium sp. was isolated from the infected Protaetia brevitarsis seulensis larvae in Korea. Under the scanning electron microscope, the isolate, Metarhizium sp. KMA-1, showed distinct formation of conidia on the palisade-like masse which were comprised of elongate chains and this shape is a typical feature of Metarhizium species. PCR techniques were used to identify the isolate and the primers used were designed on the basis of two kinds of rRNAs sequences, 28S rRNA and internal transcribed spacer(ITS). The specific PCR products from each primer set were amplified and the DNA sequences were determined for the similarity comparison. Sequence alignment of these fragments using GenBank database resulted in the highest homology similarity between the isolate Metarhizium sp. KMA-1 and M. anisopliae. From these results, the isolate Metarhizium sp. KMA-1 in this study was identified as M. anisopliae.

• Entomological Research
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• v.48 no.6
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• pp.550-558
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• 2018

To develop a system for the mass production of Protaetia brevitarsislarvae (Pbl), this study analyzed the oviposition characteristics of third instar Pbl through successive rearing and cold treatments. In the first generation, females laid 50 eggs each on average, and spawned higher numbers of eggs for the first 5 days but then fewer after this. However, all of the $2^{nd}$-generation females that were produced through the successive rearing of eggs from the $1^{st}$ generation did not spawn. When test insects (TI) were raised at $32^{\circ}C$, their $mean{\pm}SE$ pupal period and emergence rate were $28.4{\pm}1.9$ days and 87%, respectively. However, most individuals raised in cold treatments ($5^{\circ}C$ and $-5^{\circ}C$) without a pre-cooling period did not survive. Individuals exposed to a pre-cooling period, however, had a 7-10 days longer pupal period than those raised at $32^{\circ}C$, and their emergence rate (90%) was slightly higher. Different cold treatment temperatures ($0^{\circ}C$, $3^{\circ}C$, or $5^{\circ}C$) and periods (30 or 60 days) were tested in further experiments. The experimental group kept for 30 days at $0^{\circ}C$ and $3^{\circ}C$ had the shortest pupal period of all, and emergence rates exceeded 90% in most groups. With respect to the number of eggs spawned by the second generation females after cold treatments, the experimental groups held in cold treatments at $5^{\circ}C$ for 30 and 60 days were found to spawn the most eggs. Consequently, the experimental group kept at $5^{\circ}C$ for 30 days was the most effective set of conditions tested during the entire breeding period.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.377-385
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• 2022

Most pruning branches of mulberry, Korean raspberry (bokbunja), and blueberries are discarded without use. These discarded pruning branches were utilized as feed in the investigation of the development and oviposition characteristics of Protaetia brevitarsis with a focus on breeding possibilities. It was observed that the developmental period of P. brevitarsis larvae fed with berry fermented sawdust from mulberry, bokbunja, and blueberry was shortened to 157.3 130.3 days, and 140 days, respectively, compared to 169.3 days for those fed with oak fermented sawdust. The weight and survival rate of the larvae also increased. Under all three types of fermented sawdust feed, the percentage of larvae with weight ≧ 2.5 g during the group was over 60% between 6-8 weeks after hatching; however under oak fermented sawdust feed, it was within 10%, and the percentage only increased after 10 weeks. The average number of eggs laid per female was ≧ 80, with an average oviposition period of approximately 9 weeks; however, there was no significant difference owing to the large deviation per individual. Furthermore, mixed fermented sawdust from the three berries enhanced the growth rate of larvae, and there was no difference in the number of eggs laid compared to those fed with control oak fermented sawdust. Our study demonstrates berry fermentation sawdust is just as effective as oak fermentation sawdust in the breeding of P. brevitarsis.

• Korean Journal of Environmental Biology
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• v.37 no.1
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• pp.60-67
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• 2019

The objective of this study was to verify the stability of nutrient composition by using herbal medicine by-products as an alternative food source and to examine the growth effect on Protaeria brevitarsis seulensis larvae. As a result of comparing the nutritional components of food source, crude protein, crude fat, and crude ash content, except crude fiber content, was high in both non-fermented and fermented medicinal herbal by-products. Especially, crude protein content was highest. Cadmium, lead, mercury, and other heavy metals were not detected and thus stability as alternative food was confirmed. The growth comparison based on the feeding sources showed no significant difference between the fermented oak sawdust fed control group and the herbal medicine by-products fed laboratory group from week 1 to week 3. The weight of a 4 week larva was 0.137 g in the control group and 0.671 g in the laboratory group and so began to reveal differences at a significant level (p<0.05). As a result of comparing weights of Protaetia brevitarsis seulensis larvae according to the level of herbal medicine by-product addition, HMB40 recorded the heaviest weight in week 7. Statistical analysis showed that there was no significant difference in each body weights of HMB40 and HMB80 at week 5 (p<0.05). These results indicate that if the shipping date of an edible insect is a third instar larva, it arrives at the time of shipment at week 5. Thus feeding HMB40 and HMB80 at the 5th week is the most effective.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.183-191
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• 2023

After examining the temperature change in berry sawdust during the fermentation period and the developmental characteristics of Protaetia brevitarsis larvae according to the fermentation period, it was found that the fermentation speed was faster than with oak sawdust and a fermentation period of 50-70 days was the most suitable for larval growth. During the fermentation period, the temperature change in sawdust was quickly fermented as berry sawdust passed a high temperature of more than 60℃ in the early stages of fermentation compared to fermentation speed of oak sawdust, and stabilized within 60 days. In individual breeding, the total growth period of P. brevitarsis larvae by fermentation period was the longest at 104.8 days after fermentation for 30 days, which was a significant difference. There was no difference in the growth period between 50 and 90 days of fermentation. Oak sawdust tended to be the same as berry sawdust, but the larval development period was approximately 30 days. The developmental period by larval stage differed greatly between berries and oak sawdust. The weight of larvae according to the fermentation period of sawdust was the lowest after 90 days of fermentation, with a long fermentation period for both berry and oak sawdust, and there was no difference in the 30-70 days fermentation periods. The survival rate was more than 95% in individual breeding, and there was no difference among the fermentation periods. However, in group breeding, the survival rate was lower than that of individual breeding and was lowest at 90 days of fermentation. In group breeding, the ratio of larvae weighing ≥ 2.5 g, which is the standard for shipment, was 85% after 30-70 days of fermentation of berry sawdust, but was lower at 70% after 90 days of fermentation, which was a significant difference. The survival rate with oak sawdust showed the same trend, which was approximately 10% lower than that with sawdust. In addition, the larvae from the berry sawdust weighed > 2.5 g in 40-60 days, while it took 75-105 days with oak-fermented sawdust.

• Journal of Life Science
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• v.32 no.10
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• pp.784-791
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• 2022

This study observed changes in the body composition of Protaetia brevitarsis sinulensis larvae when reared with feed that included noni and nipa palm. Compared to the control group, the death rate and product yield of the treatment group were improved after the larval fasting process. The brightness of the larval powder of the treatment group increased, but the redness decreased. The crude fat content of the treated group was slightly increased according to the assays of the general components, but the mineral content was significantly increased. The total structural amino acids of the treatment group decreased, but the total free amino acids increased. The structural amino acids generally tended to decrease in the treatment group. However, the free amino acids showed no specific differences. Among the free amino acids, tryptophan, phosphoserine, and methylhistidine were highly increased in the treatment group, whereas threonine, methionine, and asparagine showed the opposite results. Among the polyunsaturated fatty acids, eicosapentaenoic acid (C20:5n3) of omega-3 was increased in the treatment group, but the omega-6 series was decreased. Since minerals, total free amino acids, and omega-3 fatty acids in the treatment group were increased compared to the control group, we suggest that noni and nipa palm can potentially be applied to the production of functionally improved substances as additional sources of feed for Protaetia brevitarsis sinulensis larvae.

• Journal of Environmental Science International
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• v.33 no.2
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• pp.187-191
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• 2024

This study aimed to investigate the effect of treating environmental purification insect larvae to pig manure on crude ash contents and ammonia production. The experiment set up consisted go two groups: 1 kg of each 3^rd instar TM (Tenebrio molitor) and 3^rd instar PBS (Protaetia brevitarsis seulensis) larvae in Experiment 1 or 3^rd and 4^th instar of HI (Hermetia illucens L.) larvae in Experiment 2 were treated with 5 kg of pig manure. In Experiment 1, the crude ash content was higher in TM larvae-treated pig manure at days 0 and 5 (p>0.05), but was similar to that in PBS larvae-treated pig manure over (p>0.05). Ammonia production was observed at day 0 of TM and PBS larvae-treated pig manure (p<0.05), but did not occur thereafter. For Experiment 2, there was significant difference in crude ash content of 3^th and 4^th instar HI larvae-treated pig manure on day 15. Additionally, ammonia production was found in 3^th and 4^th instar HI larvae-treated pig manure at days 0 and 5, but did not continue over time. In conclusion, treating TM, PBS and HI to pig manure changed the crude ash contents and reduced ammonia through the ability to decompose pig manure. Thus, environmental impact can be minimized using environmental purification insect larvae.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1164-1170
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• 2017

Protaetia brevitarsis larvae (PBL) has recently been registered as a temporary food in Korea, and this study evaluated the application potential of PBL proteins as health functional food materials. Protein hydrolysates were prepared from PBL powder by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain), and based on the results from the peptide content and SDS-PAGE analyses, PBL treated with alcalase or flavourzyme showed a high degree of hydrolysis (HD) value, whereas the HD value of those treated with neutrase, bromelain, or papain was minimal. The protein hydrolysates showing a high HD value were separated further into the fractions of >3 kDa and <3 kDa by a centrifugal filter system and then lyophilized, and according to the $RC_{50}$ values of the protein hydrolysates (<3 kDa) obtained from three different antioxidant analyses; the alcalase hydrolysates showed the highest antioxidant activity. Therefore, the alcalase hydrolysates were tested further for their inhibitory effects on the peroxidation of linoleic acid by measuring the thiobarbituric acid values. The results showed that the peroxidation of untreated linoleic acid increased dramatically during 6 days of incubation, but a pretreatment with the hydrolysates ($100{\sim}800{\mu}g/mL$) significantly inhibited the linoleic acid peroxidation in a dose-dependent manner for 6 days. Our current studies are focused on the identification of active peptide sequences from alcalase hydrolysates.