Entomological Research最新文献

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.

Sustainable approaches to managing poultry waste, such as its use as manure, are urgently required to address emerging concerns under increasing demand for poultry products. Incorporating coffee marc and bentonite as part of the waste processing by Tenebrio molitor (TM) larvae presents effective strategies for addressing these challenges. The present study investigated the capacity of 4th and 6th instar TM larvae to biodegrade poultry manure following treatment with coffee marc or coffee marc and bentonite, based on ammonia (NH₃) contents and physicochemical characteristics of poultry manure. The three treatments adopted in the present study included 2 kg of poultry manure (T1), 1 kg of poultry manure + 1 kg of coffee marc (T2), and 1 kg of poultry manure + 0.9 kg of coffee marc + 0.1 kg of bentonite as a basis of 0.2 kg of 4th or 6th instar TM larvae (T3). The 4th and 6th instar TM larvae had no significant effect on biodegradation capacity. Nevertheless, a significant difference in NH₃ flux occurred during the experiments. In the 4th instar TM larvae treatments, significant differences in pH, total nitrogen (TN), and ADF occurred among all treatments; conversely, in the manure treated with coffee marc and bentonite, 6th instar TM larvae had significant effects on pH, dry matter (DM), TN, ADF, and NDF content compared with only poultry manure. In conclusion, 6th instar TM larvae reared on poultry manure with coffee marc and bentonite could decrease the environmental impact during composting.

The flower bugs, Orius maxidentex Ghauri and Orius minutus (Linnaeus), are important natural enemies of agricultural pests such as thrips and aphids. Insect olfactory systems play an important role in chemical communication, aiding them in locating host or prey habitats. To gain a deeper understanding of the role that sensory organs play in the biological behaviors of these flower bugs, the external structures of antennae and antennal sensilla were demonstrated using scanning electron microscopy (SEM). The antennae of the two species are linear in shape and consist of scape, pedicel, and two flagellomeres. The antennae of O. maxidentex were shorter compared to those of O. minutus. Additionally, the total length of the male antennae was longer than that of the female antennae in both species. Four types and four subtypes of antennal sensilla were documented in both species, including sensilla trichodea (ST I and ST II), sensilla chaetica (SCh I and SCh II), sensilla basiconica (SB), and sensilla campaniformia (SCa). Sexual dimorphism was not observed in the type and distribution of antennal sensilla but existed in the abundance of sensilla basiconica. Our findings provide important insights for future studies on defining the olfactory function of flower bug antennae using electrophysiological methods, especially in the heat-resisting species O. maxidentex.

This study evaluated the insecticidal, repellent, and fumigant activities of four plant-derived extracts: Ficus carica (common fig), Eruca sativa (arugula), Portulaca oleracea (common purslane), and Lupinus albus (white lupin) against adult Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Gas chromatography–mass spectrometry (GC–MS) analyses identified key bioactive compounds, including unsaturated fatty acids, phytosterols, and tocopherols, which may contribute to their insecticidal and repellent properties. In the residual paper technique, F. carica extract exhibited the highest mortality (22% at 100 mg/mL), followed by E. sativa (14%) and L. albus (6%), while P. oleracea induced only 2% mortality. Repellency bioassays revealed strong deterrent effects, particularly for F. carica and E. sativa. After 3 h, F. carica exhibited 98% repellency at 2 mg/cm², maintaining 66% at 0.5 mg/cm² and 56% at 0.125 mg/cm², indicating broad-spectrum efficacy. E. sativa followed with 64% repellency at 2 mg/cm², sustaining over 50% repellency across all concentrations. Although repellency declined over time, F. carica retained 70% at 2 mg/cm² after 24 h, while E. sativa maintained 64% repellency. In contrast, L. albus and P. oleracea exhibited weaker repellency. These findings highlight the strong repellent effects of F. carica and E. sativa, suggesting their potential as natural alternatives to synthetic insecticides in stored grain pest management. Under fumigation conditions, F. carica, E. sativa, and P. oleracea exhibited minimal insecticidal activity, and L. albus had no measurable effect. These results indicate that the primary potential of F. carica and E. sativa lies in their strong repellency and moderate contact toxicity, rather than fumigation.