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.

We analyzed comparatively the ground beetle communities of 1993 and 2023, with 30 year interval, in broadleaf and coniferous stands of the Gwangneung forest, a biosphere reserve in South Korea. 2,906 individuals (53 species, 38 genera, and 15 families) were collected from broadleaf stands and 1,782 individuals (36 species, 32 genera, and 14 families) from coniferous stands in 1993. The dominant species was Synuchus cycloderus in both stands. In 2023, 1,682 individuals (110 species, 78 genera, 21 families) were collected from broadleaf stands and 990 individuals (92 species, 67 genera, 22 families) from coniferous stands. In 2023, the dominant species were Eucarabus (Parhomopterus) sternbergi sternbergi in broadleaf stands and Coptolabrus jankowskii jankowskii in coniferous stands. Species richness (R'), species evenness (E'), species diversity (H'), and dominance (DI) were all higher than in broadleaf (R'=15.472, E'=0.336, H'=1.601, and DI=0.371) and coniferous (R'=13.756, E'=0.369, H'=1.324, and DI=0.326) forests in 2023.

경상북도에 위치한 산림유전자원보호구역내 2개 지역(영주지역의 신갈나무, 울진지역의 소나무)과 경기 포 천시에 위치한 생물권보전지역내 2개 지역(포천지역의 신갈나무와 소나무)에서 2016년부터 2017년까지 함정 트랩(Pitfall trap)을 매년 5회씩 5반복하여 각각 비교하였다. 그 결과 산림유전자원보호구역에서는 27과 106속 160종 2,665개체가 확인되었으며, 종풍부도는 20.28, 종균등도는 0.266, 종다양도는 1.355, 우점도는 0.265로 우점 종은 납작먼지벌레속 sp.2 (Synuchus sp.2)이였다. 또한, 생물권보존지역에서는 16과 49속 77종 4,834개체가 확 인되었으며, 종풍부도는 8.958, 종균등도는 0.301, 종다양도는 1.31, 우점도는 0.669로 우점종은 윤납작먼지벌레 (Synuchus nitidus)였다. 산림의 중요 지역 간에 지표성 딱정벌레의 군집을 비교함으로써 환경변화에 따른 산림 보존 프로그램을 수행하는데 유용한 기초 자료로 활용될 것이다.

최근 친환경 노지 감귤원을 중심으로 알락하늘소 피해가 증가하고 있지만 효과적인 예찰 방법이 없는 실정이 다. 본 연구에서는 알락하늘소 성충 예찰을 위하여 카이로몬을 선발하였고, 알락하늘소가 다발생(>100마리)한 과원 3개소에서 유인력을 평가하였다. 시험 결과, 집합페로몬 단독처리 시 알락하늘소 암컷 성충에 대한 유인효 과를 확인할 수 있었지만 소수 개체만 유인이 되었고, 카이로몬(Kairomone) 단독 처리 시 알락하늘소 성충 포획 수가 증가하는 것을 확인할 수 있었다. 집합페로몬과 카이로몬을 동시 처리 시 알락하늘소가 대량으로 유인되는 것을 확인할 수 있었다. 이는 알락하늘소가 종내신호물질(집합페로몬)을 인지할 때 서식지로서 적합한지 판단 의 기준으로 기주식물의 존재여부를 동시에 확인하기 떄문인 것으로 판단된다.

Insect cuticle is an extracellular matrix formed primarily from two different biopolymers, chitin and protein. During each molt cycle, a new cuticle is deposited simultaneously with degradation of the old cuticle by molting fluid cuticle degrading-enzymes, including epidermal chitinases (CHTs). Insect CHTs, belonging to family 18 glycosylhydrolase (GH18), have been classified into at least eleven subgroups based on phylogenetic analyses, and group I (CHT5) and group II (CHT10) epidermal CHTs present in molting fluid. In this study we report the physiological function of MaCHT5 and MaCHT10 in the Japanese pine sawyer, Monochamus alternatus. RNAi for either MaCHT5 or MaCHT10 resulted in larval-pupal and pupal-adult molting defects, in which the insects were unable to shed completely their old cuticle and died entrapped in their exuviae. Furthermore, TEM analysis revealed a failure of degradation of the old cuticle in both MaCHT5- and MaCHT10-deficient pharate adults. In the old pupal cuticle, the chitinous horizontal laminar and vertical pore canal essentially remained intact in the endocuticular layer. These results indicate that both CHTs are required for turnover of the chitinous old cuticle, which is critical for completion of insect molting. We also discuss the possible function of two spliced variants of MaCHT10, MaCHT10a and MaCHT10b.

A taxonomic study of Korean Psammodiini is present. Seven species [Rakovicius coreanus (Kim), Leiopsammodius japonicus (Harold), Psammodius flavolittoralis Kim, Psammodius hangangensis Kim, Psammodius sungshinarum Kim, Rhyssemus inscitus (Walker), Trichiorhyssemus asperulus (Waterhouse)] belonging to five genera are recognized based on morphological characters. A pictorial key, habitus photographs and illustrations of the diagnostic characters of Korean Psammodiini species are provided to facilitate identification.

Because of recent reports about phosphine resistance problem, development of effective fumigation method to control grain pests became very important. In this study, a chemical treatment, ethyl formate fumigant treatment, and a physical treatment, atmospheric control, were attempted as alternative solutions to this problem. In this study, for CA(Controlled atmosphere) treatment, 99.999% nitrogen was used to create a hypoxic condition with less than 5% oxygen, and for EF, the treatment concentration was 10 mg/L to 80 mg/L. As a result of the study, in CA single treatment, adult insects showed a mortality rate of less than 10% even after 2 weeks of treatment, and pupae and larvae showed a mortality rate 71% and 34%, but eggs showed a mortality rate of 100%. In EF single treatment, adults and larvae showed a 100% mortality rate at 80 mg/L, but eggs showed a 50% mortality rate and pupae were not affected. Considering the results, CA single treatment is not suitable for controlling Tribolium castaneum because of long treatment period, and in the case of EF single treatment, additional researches on longer treatment time is needed.

Beetles are one of the most effective transportation for phoretic chelicerata. They use various methods to attach themselves to their hosts, such as developing ventral sucker plates, grasping with their claws and chelicerae, or hiding beneath the elytra. Recently, we discovered new species of two genera: Antennoseius (Mesostigmata: Blattisociidae) and Gaeolaelaps (Mesostigmata: Laelapidae) which are hiding under the elytra of Carabidae hosts. In this study, digital images of the beetles, and mites, along with brief diagnostic information and line-drawing plates will be provided.

Lytic polysaccharide monooxygenases (LPMOs) catalyze the oxidative cleavage of glycosidic bonds in crystalline polysaccharides including chitin and cellulose. The recent discovery of LPMO family proteins in many insect species suggests that they presumably play a role in chitin degradation in the cuticle/exoskeleton, tracheae and peritrophic matrix during insect development. Insect LPMOs belong to auxiliary activity family 15 (AA15/LPMO15) and have been classified into at least four groups based on phylogenetic analysis. In this study, we identified, characterized and investigated the physiological functions of group I LPMO15 (MaLPMO15-1 and PhLPMO15-1) in two longhorn beetle species, Monochamus alternatus and Psacothea hilaris. In both species, depletion of LPMO15-1 transcripts in last instar larvae by RNAi had no effect on subsequent larval-pupal molting and the resulting pupae developed normally. However, adverse effects on their development were observed during the pupal-adult molting period. The pharate adults were unable to shed their old pupal cuticle and died entrapped in their exuviae probably due to a failure of degradation of the chitin in their old cuticle, which is critical for completion of the insect molting and continuous growth.

Insect eggshell and cuticle/exoskeleton play vital roles in protecting them from natural environmental stresses. However, these chitinous cuticular extracellular matrices must be degraded at least in part during embryo hatching and molting/ecdysis periods to accommodate continuous growth all the way to the adult stage. In this study, we investigated the functional importance of groups I and II chitinases, TcCHT5 and TcCHT10, in the turnover of chitinous cuticle during both embryonic and post-embryonic development in Tribolium castaneum. RNAi and TEM analyses revealed that TcCHT10 is required for digestion of chitin in the serosal cuticle for embryo hatching as well as in the old cuticle during post-embryonic molts including larval-pupal and pupal-adult metamorphosis. TcCHT10 appears to be able to substitute for TcCHT5 in all these vital physiological events except for the pupal-adult molting in which TcCHT5 is indispensable for complete digestion of chitin in the old pupal cuticle.