• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.185-190
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• 2013

The superworm, as known the larva of Zophobas morio, has been officially imported from 2011 and bred commercially in Korea. But it is named as the corrected scientific name, Zophobas atratus by junior synonym throughout traditional taxonomy in this study and newly designated Korean name as 'a-me-ri-ca-wang-geo-jeo-ri' in terms of resource management. Z. atratus was compared with wild native tenebrionids, Promethis valgipes and a commercial reared Tenebrio molitor on the basis of DNA barcode analysis. As the results, the average genetic divergence was 21.4% between Z. atratus and P. valgipes, and 20.9% between Z. atratus and T. molitor. These large divergences imply these tenebrionids species can be easily identified by DNA barcodes. The results of genetic divergences within species also suggest that Korean populations of Z. atratus, having the same haplotype, might be introduced from the same area of foreign country. On the other hand, a population of T. molitor was separated into two distinct intra-specific groups with DNA barcoding gaps ranged from 1.17- 2.19%. We suppose that domestic breeding entities of T. molitor might be introduced and mixed from two different local groups. Through this study, we expect that classification for two tenebrionid introduced from foreign countries can be used for the management of insect resources in Korea.

• International Journal of Industrial Entomology and Biomaterials
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• v.30 no.2
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• pp.45-49
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• 2015

The giant mealworm beetle, Zophobas atratus (Coleoptera: Tenebrionidae), is reared for commercial purposes as a live feed for animals. In 2011, it was officially introduced in Korea, and since then it has been considered commercially important. This beetle is a good animal feed resource because of its high protein content with balanced nutrients. However, its life stage characteristics have not been clearly described, especially of the larval stage that can be used as commercial products. To this end, in our study, we determined the number of Z. atratus larval instars, and described their characteristics at each stage, providing basic information about this beetle. Z. atratus larvae required eight to nine d of incubation period before hatching. The first instar period comprised three to four d. There were relatively large variations in each instar period, except for the first instar. Before the adults emerged, most of the individuals passed through15 to 18 instars. The highest pupation rate, 25.71%, was observed in both 16th and 17th instars. Body length gradually increased with each successive instar and it reached its maximum at the 18th instar. The color of larvae was white at the first instar, and gradually turned brown after the second instar.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.2
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• pp.73-81
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• 2018

The giant mealworm beetle, Zophobas atratus (Coleoptera: Tenebrionidae), is a tropical beetle. As this beetle can be used as an ingredient in animal feed, the effects of brewer's spent grain (BSG) on the development and nutritional value of Z. atratus were investigated. As results, there were no significant differences on the larval survival rate, body weight, and duration at different content of BSG, mixed with conventional feed, wheat bran (WB). Based on these results, BSG can be mixed with wheat bran as a Z. atratus food ingredient without any problems. The nutritional value was compared between 100% wheat bran control and 50% BSG experimental groups. The moisture, crude protein, carbohydrates, and amino acids were 1.1-1.4 times higher in the 50% BSG group. In the BSG group, the linoleic acid content was 1.6 times higher than that in the control group. In the wheat bran group, the oleic acid content was 38.4%, which was 1.3 times higher than that in the BSG group. As minerals, the control and BSG groups showed high potassium and phosphorus contents. In terms of hazardous materials, four heavy metals (lead, mercury, arsenic, and cadmium) and two microorganisms (Escherichia coli and Salmonella spp.) were not detected. There were no significant differences in developmental characteristics between the wheat bran and BSG mixed groups, and the nutritional values were better in the BSG mixed group. Therefore, BSG can be used as alternative food source for rearing Z. atratus.

• Journal of Life Science
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• v.29 no.12
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• pp.1378-1385
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• 2019

The nutritional composition and optimal eating stage of the super mealworm, Zophobas atratus (Coleoptera : Tenebrionidae), were investigated to explore its use as a food ingredient. It was determined that 10^th instar larvae were most suitable for eating in terms of nutritional value as well as economic aspects. To improve the quality of powder production, the nutritional value of 10^th instar larvae before and after degreasing was analyzed. After drying the larvae powder, crude protein was the most abundant nutrient both before (52.3%) and after (60.6%) degreasing while crude fat measured 36.3% and 21.7% before and after degreasing, respectively. In terms of essential amino acids, leucine levels were highest and 1.3 times greater after degreasing (4.5%) than before (3.5%). Oleic acid, the highest unsaturated fatty acid in larvae, was 31.7% after degreasing which was 1.1 times higher than before (33.2%). Among various major minerals, potassium was most abundant and 1.4 times higher after degreasing (1267.0 mg/100 g) than before (879.3 mg/100 g). Harmful substances were 1.3 to 2.0 times lower in the degreased larvae, although mercury or pathogenic bacteria were not detected in either group. We therefore conclude that degreased Z. atratus larvae are more suitable for eating than before degreasing.

• Journal of Life Science
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• v.30 no.12
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• pp.1109-1117
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• 2020

In order to verify whether Zophobas atratus is an edible insect, the nutrients and harmful substances of Z. atratus larvae reared with an artificial diet (AD) and wheat bran (WB) were compared and analyzed. Based on dry weight, the crude protein content of Z. atratus larvae reared with an AD was 62.4%, 1.4 times higher than that of those reared with WB (45.2%). The crude fat content was 20.5% in the AD group, 2.3 times less than in the WB group (46.3%). The leucine content was 1.4 times higher in the AD group (4.2%) than in the WB group (3.0%). The glutamic acid content of nonessential amino acids was 1.3 times higher in the AD group (7.0%) than in the WB group (5.3%). The oleic acid content was 1.4 times higher in the WB group (37.0%) than in the AD group (26.7%). The potassium content was 1.1 times higher in the AD group (975.9 mg/100 g) than in the WB group (872.9 mg/100 g). According to the results of the toxic substances analysis, the lead and cadmium levels of the WB and AD groups were standard for edible insects. Pathogenic microorganisms, such as E. coli and salmonella, were not detected in either group. According to the results of the present analysis of nutrition and harmful substances, Z. atratus larvae raised on an AD are safe and contain various nutrients. Therefore, such larvae could be useful sources of food and feed.

• Journal of Life Science
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• v.30 no.9
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• pp.804-812
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• 2020

The giant mealworm beetle, Zophobas atratus (Coleoptera: Tenebrionidae) has been used as a protein source for small pets and mammals. Recently, it was temporarily registered in the list of the Food Code. We previously performed an in silico analysis of the Zophobas atratus transcriptome to identify putative antimicrobial peptides and identified several antimicrobial peptide candidates. Among them, we assessed the antimicrobial and anti-inflammatory activities of zophobacin 1 that was selected bio-informatically based on its physicochemical properties against microorganisms and mouse macrophage Raw264.7 cells. Zophobacin 1 showed antimicrobial activities against microorganisms without inducing hemolysis and decreased the nitric oxide production of the lipopolysaccharide-induced Raw264.7 cells. Moreover, ELISA and Western blot analysis revealed that zophobacin 1 reduced expression levels of pro-inflammatory enzymes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). We also investigated expression of pro-inflammatory cytokines (interleukin-6 and interleukin-1β) production through quantitative real time-PCR and ELISA. Zophobacin 1 markedly reduced the expression level of cytokines through the regulation of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB) signaling. We confirmed that zophobacin 1 bound to bacterial cell membranes via a specific interaction with lipopolysaccharides. These data suggest that zophobacin 1 could be promising molecules for development as antimicrobial and anti-inflammatory therapeutic agents.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.357-368
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• 2022

We investigated the developmental characteristics of super mealworm (Coleoptera: Tenebrionidae) at four different temperatures (25℃, 27℃, 30℃, and 33℃). The rearing conditions were 9L/15D, 65% RH, and 1,330 to 1,800 lux with wheat bran. The length of developmental period of 1 to 18 instars at each temperature showed that 30℃ was the shortest at 120.0±5.8 days, compared to that at 27℃ (132.6±10.7 days), 33℃ (136.5±9.2 days), and 25℃ (156.7±7.5 days). The larval developmental period was statistically significantly longer at 25℃, 27℃, and 30℃ compared to the length at 33℃. However, the death rate of larvae at 33℃ was 2.7-3.3 times higher than the rate at other temperatures. Body weight was heaviest at 30℃ followed by 27℃, 33℃, and 25℃. The patterns of head capsule, body capsule, and body length were similar to that of body weight. Regression analyses of developmental period, larval body weight, and length according to temperature revealed 29-30℃ as the most suitable temperature. The prepupa rate was 43.1% in 17 instars, 30.3% in 18 instars, 15.4% in 16 instars, 7.1% in 19 instars, 2.2% in 15 instars, and 1.9% in 20 instars, accounting for 88.8% in 16-18 instars. Prepupal period was longer at lower temperatures. For the average prepupal period of 15-18 instars, prepupa time was 18.8±1.9 days at 27℃, 18.8±2.3 days at 30℃, 23.0±2.4 days at 33℃, and 23.1±2.9 days at 25℃. The average pupal period of females and males was 11.1±2.2 and 11.6±2.4 days, respectively. The data indicate that the most suitable rearing temperature of super mealworm was 30℃.