Entomological Research最新文献

Strawberry (Fragaria ananassa Duch) is a fresh agricultural product and a major export commodity of South Korea. Bemisia tabaci (Hemiptera: Aleyrodidae) is an economically important pest in agriculture. We investigated the effects of electron beam and X-ray irradiation on the disinfestation of B. tabaci in packaging boxes of fresh strawberries intended for export. Hatching of B. tabaci eggs was completely prevented by both electron beam irradiation at 150 Gy and X-ray irradiation at 70 Gy. Nymphal development into adults was entirely inhibited by 150 Gy of either electron beam or X-ray irradiation. When B. tabaci adults were irradiated with 100 Gy (both electron beam and X-ray), some adults laid eggs, but none of the eggs hatched. To assess the efficacy of electron beam and X-ray irradiation for quarantine treatment, B. tabaci individuals were placed at the top, middle, and bottom layers of strawberry packing boxes and exposed to various doses (150, 200, and 300 Gy) of radiation. These results suggest that a minimum dose of 150 Gy of either electron beam or X-ray irradiation is effective for controlling B. tabaci in strawberries destined for export.

Drosophila melanogaster (Meigen) (Diptera: Drosophilidae) is a globally distributed pest that causes significant losses in fruit production, and novel approaches for management need to be explored. In this study, the host selection of D. melanogaster on four fruits was analyzed, revealing that Actinidia chinensis exhibited the strongest attractive effect. Subsequently, electrophysiological activities of volatiles from A. chinensis were identified by gas chromatography-electroantennographic detection (GC-EAD). The results demonstrated that methoxyphenyloxime, 1,1,2,3,3-pentamethylcyclobutane, and m-cymene induced significant electrophysiological responses in D. melanogaster. Among these volatiles, m-cymene was shown to be attractive to this pest at concentrations of 0.2%–0.7%. However, at a concentration of 1.0%, it exhibited a significant repellent effect. Based on data from the DoOR 2.0, Or19a and Or71a were selected for computational prediction to elucidate the molecular mechanisms underlying m-cymene recognition, and Orco was included in the analysis by AlphaFold 3, Protein X, and Chai-1. The results suggested that both Or19a and Or71a form heterotetrameric complexes with Orco at a 1:3 stoichiometric ratio and that these complexes display robust binding affinities for m-cymene. The binding energy of the Or71a-Orco-ligand and Or19a-Orco-ligand complexes was (−24.50 ± 1.00) kcal/mol and (−23.13 ± 0.38) kcal/mol, respectively. Further characterization of the OR-Orco binding interfaces revealed that the positively charged regions of the two ORs were closely associated with the negatively charged regions of Orco and vice versa. This study aims to establish theoretical foundations for improved monitoring and control strategies of D. melanogaster and to provide mechanistic insights into host recognition at the molecular level.

The first documented occurrence of the invasive red swamp crayfish (Procambarus clarkii), a freshwater macroinvertebrate, in South Korea was in the 1990s. Since then, it has rapidly expanded, especially in the southwestern regions, raising serious ecological and management concerns. In 2019, it was officially designated an invasive alien species, prompting removal efforts by local governments. However, the lack of a species-specific management framework has limited effectiveness by delaying timely, coordinated responses. To address this, the National Institute of Ecology developed and published a manual based on scientific removal strategies. The manual offers detailed guidance on species identification, reporting, removal, carcass disposal, and project termination. This study presents the manual's contents and compares it with international invasive crayfish management strategies. Given the high risk of further spread in South Korea, implementing this standardized protocol is expected to improve the effectiveness and consistency of future control efforts.

The cherry tree borer, Synanthedon bicingulata (Staudinger), is considered a major boring pest on tree species belonging to the genus Prunus (Family Rosaceae). Among Prunus species, Prunus × yedoensis, the host species of S. bicingulata, is one of the most abundant roadside trees in the Republic of Korea. However, the lack of information on the infestation characteristics of S. bicingulata on P. × yedoensis hinders effective management of the roadside trees compared to those in orchards. This study aimed to investigate the infestation characteristics of S. bicingulata in relation to cracks, a common abiotic injury in roadside trees. During 2023, field investigations were conducted in three locations in the Republic of Korea, and a total of 211 infested P. × yedoensis trees were investigated. For the investigation, we counted the number of larval infestations of S. bicingulata in all P. × yedoensis planted as roadside trees. The infestation rate increased with the increasing diameter at breast height. Higher infestation rates by S. bicingulata were found in lower parts and on the south-facing tree trunk, where cracks were more concentrated. Also, significantly higher densities of S. bicingulata larval infestations occurred inside cracks than those outside. In consequence, targeting and managing cracks in tree trunks, particularly in the lower parts and on the south-facing side, is a key tactic to reduce larval infestation of S. bicingulata.

Microbiome research has advanced in recent years due to technological developments and significant cost reductions in analytical methodologies. Research on the microbiota in insects is limited compared with other animal species. This study was performed to compare the bacterial compositions in mealworms (Tenebrio molitor) among different farms in Korea. For this study, mealworm larval samples were collected from three different farms in Korea, and genomic DNA was extracted. The extracted DNA was sequenced using primers from the V3–V4 region of 16S rRNA to identify the bacterial community. The raw data were analyzed using the QIIME2 pipeline to determine the diversity, taxonomy, and differential abundance among groups. We comprehensively characterized insect-associated bacterial families in 23 individuals belonging to six phyla by sequencing 32,827 amplicons of 16S rRNA genes. A total of 637,204 sequence reads from the live and dead larvae of T. molitor from three different farms were obtained. After quality control, denoising, merging, and chimera removal, a total of 637,204 reads were obtained, identifying 32,827 bacterial amplicon sequence variants in the live and dead larvae of T. molitor from three different farms. The insect microbiota was dominated by Firmicutes (52.6%) and Proteobacteria (46.3%).

Understanding how insects coordinate immune responses with metabolic demands is key to elucidating host–pathogen interactions. Here, we performed integrated mRNA and miRNA transcriptomic profiling in Drosophila melanogaster following infection with the entomopathogenic fungal Beauveria bassiana at 12 and 24 h post-infection (hpi). Differential expression and time-series clustering revealed dynamic transcriptional reprogramming, including early immune activation, sustained oxidative stress responses, and delayed metabolic compensation. To investigate post-transcriptional regulation, we constructed high-confidence miRNA–mRNA networks by intersecting differentially expressed miRNAs and mRNAs with dual-target predictions from miRanda and RNAhybrid, retaining only canonical repression pairs (upregulated miRNAs with downregulated targets and vice versa). At 12 hpi, the network comprised 91 interactions involving 18 miRNAs and 72 mRNAs. Key regulators such as dme-miR-34-5p and dme-miR-285-5p targeted genes in immune and metabolic pathways, including Toll/IMD signaling, glutathione metabolism, and lysosome function. By 24 hpi, the network contracted to 23 interactions (12 miRNAs and 22 mRNAs), with regulatory focus shifting toward amino acid metabolism, ER stress response, and redox homeostasis. Distinct sets of upregulated and downregulated miRNAs mediated temporally resolved targeting of biosynthetic and immune-related genes. These results reveal a stage-specific, miRNA-mediated regulatory architecture that balances immune activation with metabolic adaptation. Our work presents a time-resolved dual-omics map of the Drosophila immune response to fungal infection, offering new insights into conserved regulatory mechanisms and host–pathogen interactions.

The monsoonal (seasonal) tropics of northern Australia is a global center of ant diversity but is unrecognized as such because the great majority of its species is undescribed. Here, we document undescribed diversity in the Meranoplus unicolor Forel complex, which is formally recognized as a single species occurring throughout central and northern Australia. We obtained 80 CO1 sequences from specimens collected from throughout the taxon's range, and from these we recognize 42 species, 33 from the monsoonal zone. None of the species appears to be M. unicolor. Most of the species have very limited distributions and many are represented by single collections; given that no specimens are available for most of central and northern Australia, the total number of species in the complex is likely to be in the order of twice as many as we have recognized. Our findings provide further evidence that the ant fauna of monsoonal Australia contains several thousand species, which is many more than current estimates for any other regional fauna.

Reproductive competence in male bumblebees (Bombus terrestris) is contingent upon the precise orchestration of spermatogenesis, governed by the temporal regulation of genes involved in mitochondrial metabolism and flagellar assembly. Although bumblebees serve as ecologically and agriculturally indispensable pollinators, the molecular underpinnings of testicular development in drones remain poorly elucidated. We conducted stage-resolved transcriptomic profiling of B. terrestris drone testes at three critical post-eclosion intervals—Days 1, 5, and 9—to capture gene expression dynamics associated with sperm development. A total of 620 differentially expressed genes (DEGs) were identified and grouped into four discrete temporal expression clusters. Gene Ontology (GO) and KEGG pathway enrichment analyses revealed substantial transcriptional reprogramming associated with mitochondrial bioenergetics, cytoskeletal remodeling, and flagellar motility. This transcriptomic analysis of B. terrestris drone testes identified a precise, stage-specific transcriptional program involving early proliferation and detoxification (Day 1), mitochondrial metabolic priming (Day 5), and robust activation of ATP synthesis and flagellar assembly (Day 9). Despite a slight temporal offset between molecular (Day 9) and physiological maturity (peak mating at Day 7), identified key genes—including inositol 2-dehydrogenase, flagellar attachment zone protein, flagellar hook-length control protein, and axonemal dynein intermediate chain—serve as candidate molecular biomarkers for reproductive fitness. These findings provide foundational genomic resources for advancing pollinator breeding and conservation strategies.