Tenebrio molitor(T. molitor) is gaining attention as a sustainable food source with high nutrient content. Understanding their immune system, paricularly the role of Tak1 in the Imd pathway, is essential for mass breeding. This study investigates TmTak1 function in T. molitor. we investigated the immune function of TmTak1, followed by systemic infection using E. coli, S. aureus, and C. albicans. As a result, Silencing TmTak1 significantly affects expression levels of AMPs in the whole body, Fat bodies, and Integuments. These results showed lower expression levels of AMP compared to the control group during E.coli injection.

Tumor necrosis factor receptor-associated factor (TRAF) is known to regulate antimicrobial peptides (AMPs) production in mammals. Here, to understand the immunological function of TmTRAF against microbial challenge, the induction patterns of TmTRAF against microbial infection was investigated by qRT-PCR in the whole-body and tissue of young larvae. In addition, the effects of TmTRAF RNAi on larval mortality and expression of 15 AMP genes in response to microbial infection were investigated. Our studies may help to understand the basic role of AMP production.

In insects, the glutathione S-transferase is initiated in both the detoxification process and the protection of cellular membranes against oxidative damage. In this study, we identified the open reading frame (ORF) sequence of GST-iso1 and 2 from Tenebrio molitor (TmGST-iso1 and 2). To investigate the expression patterrns of TmGST-iso1 and 2 in response to herbicide, 0.06, 0.6, and 6 ㎍/㎕ of butachlor (FarmHannong, Seoul, South Korea) was challenged into T. molitor larvae, resulting that the TmGST-iso1 were highly induced at 3 and 24 h-post injection. Whereas, the highest expression of TmGST-iso2 was detected at 24 h after treatment. This study may contribute to basic information about the detoxifying activities of T. molitor.

Pelle, a serine/threonine kinase, is an intracellular component of the Toll pathway and is involved in antimicrobial peptides (AMPs) production due to pathogenic infection. It is known that the Pelle phosphorylates Cactus and activates the NF-κB signaling pathway in Drosophila, but it is not studied in Tenebrio molitor. In this study we investigated the tissue-specific expression patterns of the Pelle following pathogenic infection at 3, 6, 9, 12, and 24 hours. Additionally, larval mortality and AMP expression against microbial injection were investigated in dsPelle-treated T. molitor larvae. Our results may help to understand the antimicrobial function of TmPelle.

It is well known that the JNK pathway regulates AMP production against pathogenic infection in both vertebrates and invertebrates. Tenebrio molitor hep (Tmhep) is an homolog of MAP kinase kinase in mammals. Here, we investigate the immunological function of Tmhep in responses in microbial infection using RNA interference technology. The results showed that silencing of Tmhep increased the larval mortality against microbial challenge, as well as reduced AMP production compared to the control group (dsEGFP-treated group). Conclusively, Tmhep plays an critical role in antimicrobial defense in T. molitor larvae.

We introduce a method for preserving yellow mealwom (Tenebrio molitor) larvae for an extended period and show that a high percentage of larvae can survive in good health under low-temperature storage conditions combined with specific diapause termination conditions. When storing larvae for 140 days, the storage temperature can be varied based on our goals, giving us control over yellow mealworm production to meet specific demands. To produce adult beetles, storing larvae at 15 ℃ with wheat bran and ending diapause at 30 ℃ resulted in 90% pupation rate, with 60% becoming adults in 21 days. If our aim is larvae production, storing them at 10–12 ℃ with wheat bran and ending diapause at 25–30 ℃ allows the larvae to reach a suitable weight for processing. This approach ensures long-term storage of yellow mealworm larvae and provides a practical way to control their development, allowing efficient mass production tailored to market demands.

갈색거저리 유충의 사료인 밀기울은 대부분 수입에 의존하고 있는데 일부 국가의 식량 수출 중단 조치 등에 따른 국제 곡물가격 상승으로 밀기울 가격은 인상되고, 식용곤충 판매가격이 하락하면서 생산비 절감을 위한 사료 개발이 요구되고 있다. 농업부산물 3종을 50% 이상 급이하게 되면 유충 생육이 저하되었기 때문에 본 연구는 적정한 배합비율을 선정하기 위해 첨가사료 20, 30% 함량으로 밀기울과 혼합하여 사료를 급이하였을 때 갈색거 저리 유충의 생육 특성과 영양성분 변화에 대해 밀기울만 제공한 대조구와 비교하였다. 부산물 A와 B, C를 각각 30% 함유한 처리구에서 갈색거저리 유충 무게는 대조구와 차이가 없음을 확인하였다. 먹이소화율은 부산물B를 20% 함유한 처리구가 80.5%로 대조구에 비해 높았고, 부산물C 30% 처리구에서 72.6%로 가장 낮았다. 갈색거저 리 유충의 생육일수 100일 기준으로 부산물B 30% 처리구에서 용화율이 76.1%로 대조구보다 1.6배 높았으며, 부산물A 20% 처리구는 29.2%로 용화율이 가장 낮았다. 갈색거저리 유충의 조단백질 함량은 부산물 C 30% 처리 구에서 대조구보다 10.3% 증가하여 아미노산 분석을 진행한 결과 sarcosine과 ornithine이 2.5배 이상 증가하였다. 이를 통해 부산물 B나 C를 30% 함유한 사료를 급이하였을 때 사육 원가를 절감하여 유충을 생산할 수 있을 것으로 사료된다.

The yellow mealworm beetle, Tenebrio molitor L. (Coleoptera: Tenebrionidae), has long been used as a key study organism in many fundamental researches, including biochemistry, physiology, and behavior. Lifespan and reproduction are two of the most important components of fitness in all insects, but it remains largely unexplored how these two traits are influenced by macronutrient intake in this beetle. In this study, we used the nutritional geometry framework to analyze the complex and interactive effects of dietary protein and carbohydrate intake on lifespan and reproductive performance in T. molitor beetle. Lifespan and the number of eggs laid throughout the lifetime were quantified from more than 2,000 individual beetles provided with one of 35 chemically defined diets representing a full combination of seven protein-to-carbohydrate ratios (P:C= 0:1, 1:5, 1:2, 1:1, 2:1, 5:1, or 1:0) and five protein plus carbohydrate concentrations (P+C=25.2, 33.6, 42, 50.4, or 58.8 %, dry mass). All measures of lifespan and egg production were expressed highly at high caloric intake, but they differed in the optimal P:C ratio where traits peaked. While lifespan was the longest at a moderately carbohydrate-biased P:C ratio of 1:1.36, the rate of egg production was maximized at a protein-biased P:C ratio of 1.75:1, suggesting a possible nutrient-mediated trade-off between lifespan and daily reproductive efforts in T. molitor beetles. Lifetime egg production was maximized at a P:C ratio of 1.31:1, which was still protein-biased but lower than that maximized egg production rate. Reproductive lifespan was the longest at a P:C ratio of 1:1.06. When given a food choice, T. molitor beetles preferred a P:C ratio of 1:1, which is closest to the ratio that enables T. molitor beetles to stay reproductively active as long as possible.

Tube, an intracellular protein of the Toll-pathway, forms a complex with Pelle and MyD88, and regulates a signal transduction to activate NF-κB in Drosophila. To understand the antimicrobial function of TmTube, the induction patterns of TmTube were investigated at 3, 6, 9, 12, and 24 h-post injection of pathogens into 10th to 12th instar larvae. In addition, we investigated the effects of TmTube RNAi on larval mortality and tissue specific AMP expression in response to microbial challenge. Our results will provide a basic information to elucidate the immunological function of TmTube

식용곤충인 갈색거저리 유충이 식품 대체원료로써 식육에 대한 대체 가능성을 타진하고자 갈색거저리 유충 분말을 대체하지 않은 제품을 대조구로 설정하고 1%, 2%, 3% 비율로 대체한 유화소시지를 처리구로 하여 4±1℃에서 1, 8, 15, 22, 29일간 저장하면서 이화학적 특성과 관능적 특성 변화를 측정하였다. 갈색거저리 유충 분말을 첨가한 처리구의 pH는 대조구보다 증가하였고, 보수성(WHC)은 저장기간에 따라 대조구와 처리구 간 유의적인 차이는 크게 나타나지 않았으나, 대체량이 많을수록 보수성이 더 우수하였다(p<0.05). 휘발성 염기태질소(VBN), 지방산패도(TBARS) 는 대조구보다 감소하였으며, 관능검사의 경우 대조구와 유의적 차이가 나타나지 않았다(p<0.05). 따라서, 처리구가 대조구보다 우수한 품질과 저장성을 가지고 있었으며, 기호적인 측면에서도 뒤처지지 않아서 갈색거저리 유충 분말로 식육을 대체하는 것이 가능하다고 판단되어 식용곤충을 식품 대체원료로 제품화하였을 때, 식용곤충에 대한 거부감을 완화하고 소비자들에게 있어 긍정적인 인식의 변화를 이끌어낼 수 있는 기초자료를 제시할 수 있었다.

The yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae), is an important industrial insect commercially produced around the world as food and feed. Temperature and nutrition are the two most influential environmental factors determining the rearing conditions in insects, but little is known about how these two factors interact to affect the performance of T. molitor larvae. In this study, we investigated the combined effects of temperature and dietary protein:carbohydrate (P:C) ratio on key performance traits in T. moltior larvae. Throughout their larval stage, the insects were reared on one of 36 treatment combinations of six temperatures (19, 22, 25, 28, 31, 34 °C) and six protein:carbohydrate ratios (P:C = 1:5, 1:2, 1:1, 2:1, 5:1, 1:0) and their survivorship, development, growth rate, and pupal mass were monitored. Survivorship was high at low temperatures (< 25°C) and high P:C ratios (>1:1), but decreased with increasing temperature and decreasing P:C ratio. Increase in rearing temperature accelerated larval development but resulted in a reduced pupal mass. Thermal optimum for pupal mass (19.3°C) was thus lower than that for development time (28.1°C). The growth rate was maximized at 27.9°C and P:C 1.65:1 and decreased as both the temperature and the P:C ratio deviated from their optimum. All four key performance traits (survivorship, development time, pupal mass, growth rate) were optimized at temperatures between 25.7 and 27.4°C and P:C ratios between 1.17:1 and 2.94:1. Our data provide insights into how the production and nutritional value of T. molitor larvae can be improved through adjusting their rearing conditions.