This study was conducted to evaluate the time required to sell Protaetia brevitarsis larvae when larvae fed on three kinds of fermented berries sawdust, such as mulberry, raspberry, and blueberry. The first instar larvae were reared in a plastic container(543x363x188mm) with designated feeds, and investigated the cumulative proportion of larvae more than 2.5g at rearing room regulated at 25±1℃ with 50~60% under 16:8(L:D). When we reared larvae for about 45 days with fermented blueberry sawdust, the cumulative proportion of larvae with more than 2.5g was over 70%. It was about 40 days shorter than fermented oak sawdust. For each group, the average survival rates of larvae at the possible time for sale were 72~93%.

Mass breeding of Protaetia brevitarsis seluensis results in the entomopathogenic fungal infection, usually Metarhizium anisoplaie. A mixture of microorganisms (Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae) delayed fungal infection by M. anisopliae, which infected fewer P. b. seluensis when the microorganism mixture was added to sawdust as feed for P. b. seluensis for 30d, their mortality rate was approximately 35% less than that of the control group, which was fed sawdust without the EM. In addition, the growth of M. anisopliae on agar media spread with each bacterium as inhibited by up to 80%.

본 연구는 흰점박이꽃무지의 안정적인 생산과 저장법 확립을 위해 수행되었다. 이를 위해 일정 기간과 온도 조건에서 흰점박이꽃무지 유충의 저장 특성을 조사하였다. 저장 시험에 사용된 유충의 평균무게는 2.1g인 개체를 사용하여 다양한 온도조건(5℃, 10℃, 15℃, 20℃, 및 25℃)에서 일정한 용기에 각각 400마리씩 넣은 후 15주간 저장처리하였다. 조사결과 각 처리구별로 초기 저장 무게에 비해 각각 47.4%, 59.4%, 65.8%, 62.6%, 및 92.8%로 변화하였으며, 생존율은 82.8%, 94.3%, 94.8%, 91.3%, 및 94.6% 이었다. 노숙된 3령 유충(개체평균 무게 2.5g)과 성장 중인 유충(개체평균무게1.8g)을 각각 500개체씩 넣은 후 10℃에서 5개월 저장 후 체중변화와 생존율을 측정한 결과 체중은 각각 86.3%, 75.2%, 생존율은 94.6%, 96.2%이었다. 저온저장시 성장 중인 유충에 비해 노숙된 유충의 체중감소율이 적게 나타났다.

Although the white-spotted flower chafers beetle, Protaetia brevitarsis, receive attention to explore useful active ingredient for the preventive effect of liver-related diseases, little is known about cosmetic effect. Here we report that the larva extract of the white-spotted flower chafers has functional cosmetic effect using the B16F10 melanoma cell and HaCaT keratinocyte cell. The ethanol extract of hot-air dried P. brevitarsis larvae showed the inhibitory activity of tyrosinase (an enzyme that regulates the melanin production) and remarkably inhibit melanin biosynthesis in the B16F10 melanoma cell. Further, the ethanol extract induced the expression of hyaluronic acid synthetase (HAS2/HAS3), which produce hyaluronan related to epidermal structure, and indeed increased hyalurona in HaCaT keratinocyte cell. Consequently, P. brevitarsis could be new functional cosmetic material for whitening and moisturizing effect.

곤충의 면역반응에 대한 연구는 곤충 체내 침입한 미생물들과 직접 반응하는 기작들을 중심으로 연구되었다. 그러나 미생물들이 곤충 체내에 침입 한 후 발생되는 다양한 미생물 분비물질에 의한 곤충 면역반응의 시작여부 등에 대한 연구는 거의 없는 실정이다. 이를 위하여 흰점박이 꽃무지(Protaetia brevitarsis seulensis) 유충의 장내에 존재하는 공생균과 체외 병원균을 동일한 조건에서 배양 하고 다양한 분비물질들이 존재 할 거라 예상되는 배양액만을 분리, 유충에 주사하여 면역반응 여부를 조사하였다. 공생균 배양액을 주입한 유충들은 비교적 건강하고 면역반응도 발생하지 않았으나 병원균 배양액을 주입한 유충의 경우 150시간 후 60% 이상 사망하였고 주사된 자리도 짙은 갈색의 멜라닌화가 관찰 되었다. 이러한 면역반응은 과립혈구세포의 리소좀(Lysosomes) 활성화 여부로 재확인 하였다. 병원균 배양액이 주입된 유충들의 경우 12시간 후 리소좀 이 ~50% 이상 활성화 되었으나 공생균 배양액이 주입된 유충들의 경우 ~5% 미만으로 활성화 되는 것으로 나타났다. 따라서 공생균 배양액내에 는 기주면역반응을 유도하는 물질들이 없거나 량이 매우 적게 존재하는 것을 추측 할 수 있었다.

본 연구는 흰점박이꽃무지(Protaetia brevitarsis seulensis (Colbe) (Cetoniidae, Coleoptera) 유충의 혈림프에 존재하는 혈구세포들의 형태 학적 특성분석을 위하여 수행하였다. 흰점박이꽃무지 유충 혈강 내에는 과립혈구세포, 세포질혈구세포, 편도혈구세포, 구상적혈구세포, 전혈구 세포, 지방혈구세포 총 여섯 종류의 혈구세포들이 관찰 되었다. 그 중 과립혈구세포는 핵, 미토콘드리아, 골지체를 포함하여 잘 발달된 세포소기관들이 관찰 되었고 외래물질 침입시 면역학적 식균작용을 수행하는 것으로 밝혀졌다. 특히, 과립혈구세포의 세포질에는 잘 발달된 리소좀(<1 ㎛ 직경)들이 세포막 주변으로 분포되어 존재하고 있음을 알 수 있었다. 식균된 외래물질은 다양한 크기의 리소좀들과 서로 합쳐지면서 외래물질을 제거하는 것으로 판단된다. 그 외 다섯 종의 혈구세포들은 외래물질 침입시 면역학적 활성화와 관계가 없는 것으로 관찰되었다.

The white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae) was recently listed as a temporal food ingredient by the Korean Ministry of Food and Drug Safety. Traditionally, this beetle has been regarded as a medicine for suppressing live cancer and preventing liver-related disease. Based on these facts, this beetle has been focused as a economically important insects in Korea. Therefore, this beetle is commercially reared and distributed in Korea. As the economic importance is growing, we have investigated to enhance insect rearing conditions for better commercial value. In this study, we compared two food supplements, clay and charcoal, on the larval weight gain for second instar larvae of P. brevitarsis. Clay and charcoal are generally known as a good adsorbent for heavy metals and bio-waste. However, clay and charcoal is not a conventional feed supplements, so its effects were not investigated for insect rearing. The second instar P. brevitarsis larvae were fed fermented sawdust with seven different combinations of cla and/or charcoal, and measured body weight for 17 weeks until pupated. Addition of clay at 2.5 % w/w of the fermented sawdust diet had no negative effect on larval weight gain, and thus may improve the quality of P. brevitarsis as a commercial food.

This study aimed to provide information and data for the management of insect breeding farms by identifying the appropriate density when rearing Protaetia brevitarsis larvae. The breeding box of the insects was filled with 2 L of fermented sawdust on a 50 × 35 × 15 cm sheet of plastic, and the density of the treatments was 200, 300 and 400 P. brevitarsis in the first, second, and third larval stages. Each treatment was repeated five times, and the sawdust medium was replaced three times (10 intervals). The experiments were conducted for a total of 30 days from March 1, 2020. Overall, 200 P.brevitarsis in the first, second, and third larval stages reared in the breeding box had a higher average survival rate and lower average mortality rate, thereby contributing to efficient production. In conclusion, this result suggests a way to increase production efficiency through the environmental management of insect breeding farms.

This study investigated the oviposition characteristics of Protaetia brevitarsis seulensis after emergence as adults from the larva collected from three regions in Gangwon-do, Chungcheongnam-do, and Jeju-do. The laying egg method was identified with zone breeding, and the average and cumulative number of eggs laid were measured once a week for seven weeks. The average number of eggs laid peaked until 4 weeks, and subsequently decreased. The source areas with respect to average number and cumulative number of eggs laid were in the order of Jeju > Chungnam > Gangwon. In conclusion, this result suggests a method for continuously improving management and economic feasibility of insect farming by securing genetic diversity, and raising the most productive breeds to select individuals form regions associated with high numbers of laid eggs.

The present study was investigated the oviposition characteristics of Protaetia brevitarsis seulensis with a focus on winter larvae to improve the utilization of insect resources. The average oviposition tendency and average cumulative number of eggs laid during a 7-week period were measured in adults emerging from larvae that had hibernated for 4 months in five farmhouses. The study covered five zones: Gimje, Jangsu, Wanju, Iksan and Yeoju. The average oviposition tendency over a 7-week period showed increased egg laying between 2 to 3 weeks and 5 to 6 weeks. Overall, it was found that the average cumulative number of eggs laid during the 7-week period was initially low and increased proportionally with time. Our results suggest that using adults that have emerged from hibernated larvae is effective in increasing the oviposition rate and utilization of the insect.