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.

Mealworm is the most widely used edible insect in Korean traditional food. In this study, the quality characteristics and antioxidant activity of Garaedduk containing different proportions of powdered mealworm (0%, 3%, 6%, 9%, and 12%) were evaluated in order to enhance the utilization of mealworm. The results revealed that moisture content decreased while pH and starch elution increased, with increasing amount of mealworm. Furthermore, the amount of total amino acids, essential amino acids, and non-essential amino acids increased with increasing amount of mealworm. Regarding chromaticity, the L value decreased while the a and b values increased as the amount of mealworm increased. The addition of 6% mealworm showed slight differences in the pore size and surface smoothness as compared to plain Garaedduk. Texture, hardness, chewiness, and gumminess increased, but cohesiveness decreased with increasing amount of mealworm. The preference test evaluating the appearance, flavor, taste, texture, and overall preference showed that 6% mealworm additive group had the highest preference. In addition, antioxidant activity of the newly developed Garaedduk increased with increasing amount of mealworm. In conclusion, Garaedduk enriched with 6% mealworm showed promising results for developing rice cake with improved nutrition and antioxidant activity and excellent overall preference and quality.

식용곤충인 갈색거저리 유충을 기능성 소재로 활용하기 위하여 갈색거저리 유충 추출물의 산화방지 성분 및 활성을 확인하였다. 동결건조한 갈색거저리 유충 분말의 일반 성분은 수분함량 0.80 ± 0.06%, 조회분 3.29 ± 0.03%, 조단백질 54.07 ± 0.24%, 조지방 36.78 ± 0.66%이었다. 갈색 거저리 유충 분말의 ethanol 농도별(95%, 70%, 50%, 물) 추출물의 총 phenolic compounds 함량은 50% ethanol 추출물에서 459.23 ± 1.05 mg/100 g으로 가장 높았으며, 총 flavonoid compounds 함량은 물 추출물에서 19.86 ± 0.69 mg/100 g으로 가장 높았다. 갈색거저리 유충 분말 추출물의 DPPH radical 소거 활성은 70% ethanol 추출물에서 82.60 ± 0.00%로 가장 높았으며, 물, 50% ethanol, 95% ethanol 추출물 순으로 높았다. ABTS radical 소거 활성은 50% ethanol 및 물 추출물에서 각각 97.57 ± 0.16%와 95.33 ± 0.41%로 높게 나타났으며, 유의적 차이는 없었다. 환원력의 경우 물 추출물에서 유의적으로 가장 높았으며, 50% ethanol, 70% ethanol, 95% ethanol 추출물 순이었다. 본 연구결과 갈색거저리 유충의 산화방지 성분의 함량이 많고 산화방지 활성을 우수함을 확인하였으며, 기능성 소재로서 활용할 가치가 있는 것으로 나타났다.

Mealworm(Tenebrio molitor) was added to the feed to improve the health of dogs. As the amount of mealworm powder added to dog feed increased from 2.5 to 7.5%, the contents of crude protein, crude fat, crude fiber and crude ash increased. In the old dogs, creatinine and BUN related to nephropathy, triglyceride related to hypertension, calcium related to osteoporosis, globulin related to immunity, and ALT related to hepatic function were in the normal range. Particularly, ALT showed a tendency to increase overall, but the numerical increase tended to decrease as the amount of mealworm powder added. In the young dogs, all investigative items such as BUN and creatine were in the normal range and ALT tended to decrease at 2.5～5.0% treatment of mealworm. As a result, it was shown that adding 2.5～5.0% of mealworm powder to feed effectively improved the hepatic function of old and young dogs.

Insect cuticle tanning (pigmentation and sclerotization) is a complex and vital physiological process that begins with tyrosine and is responsible for production of both melanin- and quinoid-type pigments. In addition, these quinones undergo isomerization to quinone methides and cross-linking reactions with cuticular proteins for cuticle sclerotization. In this study, we studied the functions of TmDDC and TmY-y as well as TmNAT1, TmADC and Tmebony from Tenebrio molitor, which are involved in the tyrosine-derived melanin- and quinoid-type pigment productions, respectively. The temporal and spatial expression patterns of the genes were analyzed by real-time PCR. RNA interference was performed to understand the genetic regulation and molecular mechanism underlying the darkening and hardening of beetle cuticle.