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.

This study presents a rapid and sequential radiochemical separation method for Pu and Am isotopes in radioactive waste samples from the nuclear power plant with anion exchange resin and TRU resin. After radionuclides were leached from the radioactive waste samples with concentrated HCl and HNO3, the sample was allowed to evaporate to dryness after filtering the leaching solution with 0.45 micron filter. The Pu isotopes were separated in HNO3 medium with anion exchange resin. For leaching solution passed through anion exchange column, the Am isotopes were separated with TRU resin. The purified Pu and Am isotopes were measured by alpha spectrometer, respectively, after micro-precipitation of neodymium. The sequential radiochemical separation of Pu and Am isotopes in radioactive waste samples using anion exchange resin and TRU resin was validated with ICP-MS system.

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.

This study presents a rapid and quantitative radiochemical separation method for Nb isotopes in radioactive waste samples from the nuclear power plant with anion exchange resin after Fe coprecipitation. After radionuclides were leached from the radioactive waste samples with concentrated HCl and HNO3, the Nb isotopes were coprecipitated with Fe after filtering the leaching solution with 0.45 micron HA filter, while the Sr, Tc and Ni isotopes were in the solution. The Nb isotopes were separated in HCl medium with anion exchange resin. The purified Nb isotopes were measured using a low level liquid scintillation counter after installing quenching curve with standard Nb-94 isotopes. The separation method for Nb isotopes investigated in this study was applied to neutron dosimeter samples from the nuclear power plant after validating the Nb activity concentration with gamma spectrometry system.

This study presents a rapid and quantitative sequential separation method for H-3 and C-14 isotopes with distillation apparatus in environmental samples released from nuclear facilities. After adding 200 mg of granulated potassium permanganate and 500 mg of sodium hydroxide in 100 mL of sample solution, the sample solution was heated until approximately 10 mL of distillate, and the distillate fraction was removed. The sample solution was heated again until a minimum 10 mL of additional distillate was collected. 10 mL of distillate was transferred to the LSC vail and the measurement sample for H-3 was made by adding 10 mL of Ultima Gold LLT to the LSC vial. After adding 2.5 g of potassium persulfate, 2 mL of 1M silver nitrate and 15 mL of concentrated nitric acid to the remained sample solution, the sample solution was heated for 90 minutes and C-14 isotopes were adsorbed into 10 mL of Carbo-Sorb solution in glass vial. The measurement sample for C-14 was made by adding 10 mL of Permafluor to the C-14 fraction in glass vial. The purified H-3 and C-14 samples were measured by the liquid scintillation counter after quenching correction. The average recoveries of H-3 and C-14 with CRM were measured to be 96% and 85%, respectively. The sequential separation method for H-3 and C-14 investigated in this study was applied to activated charcoal filter produced from nuclear power plants after validating the reliability by result of proficiency test (KOLAS-KRISS, PT-2021-51).

The Korean rhinoceros beetle, Allomyrina dichotoma (Coleoptera: Scarabaeidae), has been traditionally used for the treatment of liverrelated diseases. Recently A. dichotoma was registered as a food ingredient in Korea. Given the increasing interest in this beetle, studies on the development of safe and nutritious feed sources for its commercial production are needed. In this study, we compared the effects of by-products on the growth of third instar larvae of A. dichotoma. An abundance of food by-products have been found to serve as an alternative energy source in animal feeds with the reduced cost. We fed third instar A. dichotoma larvae feeds consisting of fermented sawdust with nine different combinations of citrus peel, soybean curd cake, soybean oil meal, and brewers’ dried grain, and measured their effects on growth until the larvae pupated. The highest survival rate was in feed supplemented with 10% of brewers’ dried grain (66.7%). Especially, larvae fed on 10% of brewers’ dried grain were 26% heavier than the control (with no supplement). For the group of 10% brewers’ dried grain, the larval period of third instar was shortened by almost 28 days compared to the control group. Of the experimental and control groups, only the group of 10% brewers’ dried grain showed more than 90% of pupation rate. Therefore, brewers’ dried grain may be sufficiently useful as a source of feed for A. dichotoma.

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.

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.

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.

Protein and carbohydrate are the two most important macronutrients that have profound consequences for the fitness of insects. Many insects are capable of balancing the intake of multiple nutrients to minimize the fitness costs associated with ingesting diets that are imbalanced with respect to protein and carbohydrate. It has been hypothesized that insects will redress the imbalance of their nutrient state through increasing the appetite for specific nutrients that are ingested in deficit. We tested this possibility using a mealworm beetle, Tenebrio molitor (Coleoptera: Tenebrionidae). Newly emerged beetles were confined to one of two nutritionally imbalanced foods that contained only protein or carbohydrate (P:C ratio = 0:42 and 42:0, expressed as % dry mass) for 16 days, after which they were given an opportunity to choose between two nutritionally imbalanced diets (0:42 versus 42:0). Over the first few days of the food choice, beetles that had previously experienced protein-limitation preferred protein to carbohydrate while the reverse was true for those that had experienced carbohydrate-shortage. Such contrasting patterns of diet preference observed between the two groups of beetles diminished subsequently as the insects recovered from nutrient imbalance. Our results provide strong support for the long-standing idea that attaining the right balance of nutrients is the main motive for foraging in insects.

본 연구에서는 pH 변화에 따른 카올리나이트-휴믹산, 카올리나이트-아메리슘 및 휴믹산-아메리슘 등의 이성분계 흡착반응을 조사하였다. 카올리나이트의 물리화학적 특성을 조사한 후, 휴믹산농도, 이온강도 및 pH 변화에 따른 카올리나이트에 휴믹산의 흡착실험을 하였다. pH 및 HA 농도가 증가함에 따라 KA에 대한 HA의 흡착율이 감소하였으나, 이온강도가 증가함에 따라 HA의 흡착율이 증가하였다. 또한 pH 변화에 따른 카올리나이트와 아메리슘과 흡착반응 및 아메리슘과 휴믹산과의 흡착반응도 연구하였다. 산성 및 중성영역에서는 Am이 HA에 쉽게 흡착되었으나, 염기성 영역에서는 정전기적 반발력으로 HA에 대한 Am 흡착이 감소되었다. 본 연구 결과는 수환경에서 휴믹산에 의한 아메리슘 흡착거동 특성을 이해하는데 활용이 가능하다