In order to improve the usability of mealworm and the nutritional quality of acorn Mook mostly composed of carbohydrates, we prepared acorn Mook using with different levels of mealworm powder, and the physico-chemical and sensory evaluation were investigated. In the content of proximate chemical composition, moisture content did not show any significant difference. But crude protein, crude ash, and crude fat contents were increased with increasing mealworm content. Carbohydrate content was reduced as mealworm content increased. Lightness showed no significant difference among treatments, redness was increased, and yellowness was decreased as the amount of mealworm powder increased. In physiological properties, hardness, gumminess, chewiness, and springiness were significantly increased as the amount of mealworm powder decreased. However, adhesiveness and cohesiveness were not significantly different. Ascorbic acid content, activities of DPPH and ABTS radical scavenging activities were decreased with increasing amount of mealworm in acorn Mook. In sensory evaluation, acorn Mook containing 0.75% of mealworm powder showed highly preference compared with the control.

The insects have been investigated as novel sources for foods and biomaterials in several recent studies. However,its effects on hair growth have not been sufficiently researched. To develop novel and natural materials for preventingalopecia and promoting hair growth, we investigated the antioxidant activity and hair growth promoting effect of Tenebriomolitor larvae extract (TME). As a result, DPPH radical scavenging activity was 81.17%, and nitrite scavenging activitywas 43.69%, which were similar to blueberry extract. And TME promoted the proliferation of human DPCs and NIH3T3cells, concentration dependently. In addition, the TME prevented not only DHT-induced DPCs cytotoxicity but also actionof TBM as a potassium channel blocker in NIH3T3 cells. These results suggest that TME can be used as a functionalmaterial for alopecia therapeutic reagent by preventing hair loss and promoting hair growth.

We recently reported the in vitro and in vivo antiobesity effects of Tenebrio molitor larvae, a traditional food in manycountries, but it remains unknown how the larvae affect appetite regulation in mice with diet-induced obesity. We hypothesizedthat the extract of T. molitor larvae mediates appetite by regulating neuropeptide expression. We investigated T. molitorlarvae extract's (TME's) effects on anorexigenesis and endoplasmic reticulum (ER) stress–induced orexigenic neuropeptideexpression in the hypothalami of obese mice. Central administration of TME suppressed feeding by down-regulating theexpression of the orexigenic neuropeptides neuropeptide Y and agouti-related protein. T. molitor larvae extract significantlyreduced the expression of ER stress response genes. These results suggest that TME and its bioactive components arepotential therapeutics for obesity and ER stress–driven disease states.

Environmental temperature has strong impacts on the rate and efficiency of nutrient use in insects, but little is knownabout how changes in temperature influence their nutrient preference. Here we examined the effect of temperature onthe nutrient preferences of mealworm beetles (Tenebrio molitor L.) by offering them a choice between two nutritionallycomplementary diets (P:C 1:5 vs. 5:1) at four different temperatures (20, 25, 30, or 35 ̊C). Beetles selected protein andcarbohydrate in a 1:1 ratio at 25 and 30 ̊C, but exhibited a significant preference for carbohydrate at 20 and 35 ̊C. Theseresults indicate that nutrient preference can shift plastically to match the altered nutrient requirement of beetles underchanging thermal conditions. The present findings have implications for the impacts of climate warming on diet selectionin insects.

This study aimed to assess fatty acid composition and anti-inflammatory effects, such as nitric oxide(NO) production, expression of TNF-α and interleukin-6(IL-6), of Tenebrio molitor larva using RAW 264.7 cells. The content of total fatty acid in Tenebrio molitor larva was 76.14%, which was composed of oleic acid(42.12%), linoleic acid(32.67%) etc. There was no cytotoxicity at a dose level of 0.1, 1.0, 10, and 100 μg/mL of freeze dried Tenebrio molitor larva ethanol extract(FDTEtOH) on RAW 264.7 cells. FDTEtOH significantly decreased NO production in LPS(lipopolysaccharide)- stimulated RAW 264.7 cells in a dose-dependent manner. Also, FDTEtOH dose-dependently suppressed the expression of TNF- α and IL-6. Thus, these results showed that Tenebrio molitor larva has the potential to be used as an anti-inflammatory food to improve immunity.

Tyrosine-mediated cuticle tanning (pigmentation and sclerotization) is a vital process for insect growth and development. In this metabolism, dopamine and N-β-alanyldopamine (NBAD) are major precursors to black melanin-like and yellowish quinonoid pigments, respectively. NBAD synthase (Ebony) catalyzes the synthesis NBAD by conjugation of dopamine and β-alanine, while NBAD hydrolase (Tan) dose a reverse reaction of NBAD synthesis catalyzed by Ebony. In this work, we cloned cDNAs of ebony and tan from two beetle species, Tribolium castaneum and Tenebrio molitor. Loss of function phenotypes produced by RNAi for these genes indicate that Ebony, but not Tan, is required for cuticle pigmentation in both beetles. This work was supported by NRFs (NRF-2015R1A2A2A01006614).

Insect cuticle/exoskeleton covering the entire external surface of the body is essential for protecting insects from various environmental stresses. Tyrosine metabolism plays a major role in not only the darkening of cuticle but also its hardening. In this work, we have focused on the functional analysis of nine genes involved in tyrosine-mediated cuticle tanning (pigmentation and sclerotization) pathway in Tenebrio molitor, which has a unique adult cuticle coloration, dark/black dorsal thorax and elytron, and reddish ventral thorax and abdomen. The temporal and spatial expression patterns of the genes were analyzed by real-time PCR, and RNA interference (RNAi) was performed to study the functional importance of these genes in cuticle coloration and/or hardening in T. molitor. This work was supported by NRFs (NRF-2015R1A2A2A01006614 and NRF-2015R1A6A3A04060323).

Myeloid differentiation factor 88 (MyD88) is an intracellular adaptor protein involved in Toll pathway. In this study, we monitored the response of 4 key genes of the insect immune system against Beauveria bassiana JEF-007 in Tenebrio molitor using RT-PCR. To better understand the roles of Toll pathway in mealworm immune system, TmGPR and TmMyD88 was knocked down by RNAi silencing. Target gene expressions were decreased at 6 days post-dsRNA injection. Therefore, mealworms were compromised by B. bassiana JEF-007 at 6 days post-dsRNA injection. Silencing of the TmMyD88 and TmGPR resulted in reducing the resistance of the host to fungal infection. However, only dsTmMyD88 showed significant difference with dsEGFP by statistical analysis, which may be due to partial gene knock down of dsGPR. These results indicate that TmMyD88 is required in mealworms for survival against B. bassiana JEF-007.

Recent research has suggested that the dietary protein:carbohydrate (P:C) balance is a critical determinant of fitness in insects. In this study, we examined the effects of dietary P:C balance on life-time reproductive success in the mealworm beetle, Tenebrio molitor. Both males and females lived the longest when fed on P:C 1:1 diet. Throughout their adult lives, females fed on P:C 1:1 diet laid significantly more eggs than those on nutritionally imbalanced diets (P:C 1:5 or 5:1). When given a choice, beetles regulated their intake of protein and carbohydrate to a ratio close to 1:1. Taken together, our results indicate the balanced intake of protein and carbohydrate maximizes life-time reproductive success in this species.

Distillers dried grain (DDG) and makgeolli spent grain (MSG) are agricultural by-product to produce alcoholic beverage. However, they are known to contain enough nutrients. Mealworm is a promising insect resource for an animal feed ingredient as well as alternative human food. With low cost, DDG and MSG were investigated as a feed ingredient for rearing high quality mealworms. DDG and MSG were mixed with wheat bran and compared to control feed (only wheat bran) for its effects on larval survivorship, larval weight, duration for larval development, pupation rate, and pupal weight. Adding DDG on wheat bran showed positive results for larval weight, duration for larval developmental period, and pupation rate. However, adding MSG made longer duration for larval development, but it also improved larval weight, pupal weight with more than 90% pupation rate. We confirmed that adding 30～50% of DDG or MSG to conventional wheat bran have a strong potential to replace the conventional wheat bran insect feed for quality insect production.

Myeloid differentiation factor 88 (MyD88) is an intracellular adaptor protein involved in Toll signaling pathway. In this study, we monitored the response of 4 key genes of the insect immune system against Beauveria bassiana JEF-007 in Tenebrio molitor using RT-PCR. TmGPR, antimicrobial peptide Tenecin 1 and Tenecin 2 were up-regulated after fungal infection. To better understand the roles of Toll signaling pathway in mealworm immune system, TmGRP and TmMyD88 was knocked down by RNAi silencing. Target gene expressions were decreased at 2 days post-dsRNA injection, and dramatically reduced at 6 days post-dsRNA injection. Therefore, mealworms were compromised by B. bassiana JEF-007 at 6 days post-dsRNA injection. Silencing of the TmMyD88 and TmGRP resulted in reducing the resistance of the host to fungal infection. However, only dsTmMyD88 showed significant difference with dsEGFP by statistical analysis, which may be due to partial gene knock down of dsGRP. These results indicate that TmMyD88 is required in mealworms for survival against B. bassiana JEF-007.

Entomopathogenic fungi are facultative microorganisms, dwelling in soil or infecting host insects, and some of the genera have been used as biological control agents worldwide. Collection of fungal isolates should be a platform for the development of highly effective resources, thus in this work we constructed a fungal library using a mealworm (Tenebrio molitor) pathogenicity-based fungal collection method and further characterized some isolates with high virulence. A phylogenetic three was generated, and of the isolates 17 isolates’ biological features were characterized, such as morphology, spectrum of virulence, cultural characteristics, thermo-stability of fungi, production of biologically active materials, such as enzymes. This work reports an attractive entomopathogenic fungal library including the information of effective isolates in pest management.

This study was performed to develop and evaluate cookies prepared with various amounts (0 g, 12.5 g, 25 g and 37.5 g) of mealworm powder to serve as not only sports snacks but also for the general population as a new protein source. In the chromaticity of mealworm cookies, lightness and yellowness decreased whereas redness increased with more mealworm powder. The hardness of the mealworm cookies increased as more mealworm powder was added. In sensory evaluation, higher preference was shown with the measure of color, taste, and overall preference for mealworm cookies prepared with 50% mealworm powder (MP2). For the general composition of MP2, the moisture, carbohydrate, crude protein, crude fat and crude ash were higher compared with the control cookie. For the mineral contents of MP2, the contents of Ca (33.44 mg/100 g), P (225.13 mg/100 g), Mg (82.21 mg/100 g), Na (246.22 mg/100 g), and K (503.49 mg/100 g) were higher compared with the control cookie. The essential amino acids (valine, isoleucine, leucine, methionine, threonine, phenylalanine, and histidine) in MP2 were also higher compared with the control cookie. It was concluded that MP2 can be used as a new protein source for not only the maintenance of muscle but also for the prevention of muscle loss in old people.

Insect is an important player in the ecosystem as a prey for animals. Moreover, they are a valuable candidate food source for rearing animal. Tenebrio molitor (Coeloptera: Tenebrionidae) larvae are known as a good food source with high protein, unsaturated fatty acid, minerals. Therefore, it has strong potential to substitute the conventional meat consumption. To utilize T. molitor as a feed, the standard mass-rearing protocol is required. To make standard mass-rearing protocol, we tested different temperature(17.5, 20, 22.5, 25, 27.5 and 30°C) conditions for egg, larvae, pupae and adult T. molitor to identify the optimal rearing condition. Hatching was occurred within 15~32.5°C range. However, 17.5~27.5°C was required to get more than 70 % hatching rete. When the eggs were treated in 22.5~27.5°C, all eggs were hatched within 10 days. As larval development, shorter developmental period, higher pupation and eclosion rates were observed within 25~27.5°C temperature range. In addition, we compared the number of egg, oviposition duration and time required to start egg-laying. The minimum egg-laying(258.40±10.86) was observed at 17.5°C, but the maximum(749.10±7.45) was at 27.5°C. The maximum oviposition duration (137.00±12.73 day (mean±S.D.)) was achieved at 27.5°C, but the minimum (87.50±3.54 day (mean±S.D.)) was at 30°C. The time required to start egg-laying was less than 10 days at 17.5, 27.5, and 30°C. To consider all the factors, we concluded that the optimal temperature is 27.5 °C.

Entomopathogenic fungi are facultative microorganisms, dwelling in soil or infecting host insects, and some of the genera have been used as biological control agents worldwide. Collection of fungal isolates should be a platform for the development of highly effective resources, thus in this work we constructed a fungal library using a mealworm pathogenecity-based fungal collection method and further characterized some isolates with high virulence. A phylogenetic three was generated, and of the isolates 17 isolates’ biological features were characterized, such as morphology, spectrum of virulence, cultural characteristics, thermo-stability of fungi, production of biologically active materials, such as enzymes. This work reports an attractive entomopathogenic fungal library including the information of effective isolates in pest management.

Protein and carbohydrate are the two most important macronutrients that have profound impacts on fitness and demography in most insects. The purpose of this study is to investigate the effects of dietary protein:carbohydrate (P:C) balance and mating status on feeding behavior, longevity and fecundity in male and female mealworm beetles, Tenebrio molitor (Coleoptera: Tenebrionidae). In the first experiment, we measured the amount of protein and carbohydrate consumed by mated and unmated beetles of both sexes. Newly emerged beetles were allowed to mate for 24 h before they were simultaneously provided with two nutritional imbalanced but complementary synthetic diets (P:C =1:5 vs. 5:1) for 24 successive days. Mated females not only consumed significantly more nutrients but also exhibited a greater preference for protein than did mated males and unmated controls. In the second experiment, we determined longevity and fecundity from a total of 120 male and female beetles that were confined to feed on one of three no-choice foods differing in P:C balance (P:C=1:5,1:1 or5:1) throughout their entire lives. Fecundity was recorded as the total number of eggs laid by individual females until death. Both male and female beetles lived significantly longer and laid more eggs over the lifetime on a balanced diet (1:1) than on the two imbalance diets (1:5 and 5:1), suggesting that the Darwinian fitness was maximized when the diet was equally balanced in protein and carbohydrate. Mated male and female beetles had a shorter longevity compared to their unmated counterparts, indicating that there was a significant survival cost to mating in this insect.