Entomological Research最新文献

The recent detection of Chironomid larvae in tap water has raised concerns about the reliability of existing disinfection processes in drinking water treatment. This study investigated the efficacy of chlorine dioxide as a control agent for Chironomid larvae and eggs, compared its performance with sodium hypochlorite, and assessed its behavior within a pilot-scale water treatment system. Laboratory bioassays were conducted using two Chironomid species and a wild community across a range of concentrations and temperatures. Chlorine dioxide exhibited significantly higher larvicidal activity than sodium hypochlorite, achieving complete mortality at lower concentrations and shorter exposure times. Temperature-dependent toxicity tests showed accelerated mortality rates at higher temperatures. Chlorine dioxide also suppressed egg hatching, reducing the hatching rate to 0% at 1.0 mg/L. Comparative analysis of five commercial chlorine dioxide formulations revealed no significant differences in toxicity, indicating consistent performance regardless of product type. In pilot-scale trials, chlorine dioxide injected at 7- to 10-mg/L effectively reduced larvae and was consistently detected at safe residual levels (< 0.8 mg/L) after treatment stages. These findings demonstrate that chlorine dioxide is a practical and scalable alternative for integrated Chironomid control in water treatment systems. The study provides a comprehensive dataset for evaluating concentration, exposure time, and environmental conditions necessary for its effective application.

Myzus persica (Sulzer) is an important agricultural pest that indirectly spreads plant viruses by feeding on plant leaves, causing significant impacts on agricultural production. Neonicotinoid insecticides exert their insecticidal effects by specifically targeting the nicotinic acetylcholine receptors (nAChRs) in the insect nervous system, thereby interfering with neural signal transduction. However, their frequent use has led to severe resistance. The mutations of the nicotinic acetylcholine receptor β1 subunit (nACh β1) in insecticide resistance formation as an important target deserve attention. So, in this study, resistance level determination, gene mutation point detection (R81T and V101I), and nAChR β1 gene expression analysis in different populations were conducted. The results showed that seven field populations collected in four provinces of China exhibited resistance to imidacloprid (resistance factor [RF] range, 3.27–108.00). The V101I mutation frequency is not found in the HNZMD population, whereas varying degrees occur in the other six populations (ranging from 10% to 100%), and this mutation frequency is significantly positively correlated with resistance level to imidacloprid. However, the R81T mutation only appeared in the HNHB and HNZMD populations, with mutation frequencies of 50% and 20%, respectively, and was not detected in the other five populations. The mRNA relative expression levels of nAChR β1 subunit showed no significant differences among the sensitive strain (MP-S), HNLY, JSLYG, CQDZ, and HNZMD. However, the nAChR β1 subunit was reduced by 60.7%, 58.7%, and 49.6% in HNHB, ZJHZ, and HNXX compared with that of MP-S, respectively. This suggests that both point mutation (V101I) and the downregulation of nAChR β1 subunit expression may be involved in the resistance to imidacloprid. These results should be useful for the management of imidacloprid-resistant M. persicae.

In this study, we elucidated the morphological characteristics of the burying beetle Nicrophorus quadraticollis (Portevin, 1903) and its complete mitochondrial genome for the first time. The phylogenetic analysis results indicate that N. quadraticollis is nested within the genus Nicrophorus (tribe Nicrophorini) and support the monophyly of Silphinae as well as its division into two tribes, Silphini and Nicrophorini. The mitochondrial genome of N. quadraticollis is circular with a length of 17,747 bp, comprising 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes, with a nucleotide composition of 40.9% adenine, 36.7% thymine, 9.0% guanine, and 13.4% cytosine. This study provides essential morphological and genomic data for N. quadraticollis, contributing to future taxonomic, phylogenetic, and evolutionary studies of Silphinae.

The pumpkin fruit fly, Zeugodacus tau (Walker) (Diptera: Tephritidae), is a polyphagous pest of horticultural crops across Asia and Oceania. Understanding its thermal biology is essential for predicting phenology and invasion risk under climate change. We examined stage-specific development at constant temperatures ranging from 11.7°C to 40.9°C. Development accelerated with increasing temperature, reaching an optimum between 25°C and 31°C, but failed to complete at ≥ 35.8°C. Linear regression estimated lower developmental thresholds of 5.0°C, 7.8°C, and 9.1°C for eggs, larvae, and pupae, with corresponding thermal constants of 31.0, 104.0, and 145.9 degree-days. The total immature stage required 285.1 degree-days above 8.3°C. Among five nonlinear models tested, the Lobry–Rosso–Flandrois (LRF) function provided the best overall fit (r² = 0.99) and, when integrated with a Weibull distribution, successfully simulated temperature-dependent adult emergence. Comparative analysis indicated that Z. tau develops more rapidly at cooler temperatures than Bactrocera dorsalis and Zeugodacus cucurbitae, suggesting a potential competitive advantage in temperate regions. Together, the estimated lower developmental thresholds, thermal constants, and nonlinear model parameters provide robust inputs for degree-day and mechanistic phenology models. These models can be used to forecast adult emergence, assess the likelihood of range expansion under climate warming, and support the development of targeted surveillance and management strategies for this invasive pest.

Protecting wooden cultural heritage inherited from our ancestors in its original form and cultural value is essential to pass it on to future generations. However, some wooden cultural heritage sites in Korea are at risk due to termite infestations. The structural damage caused by termites is irreversible and requires immediate attention. In this review, we summarize termite research in Korea and discuss current control measures used to manage termite infestations in wooden cultural heritage, based on a decade-long biological damage management project (2013–2023). We conducted a comprehensive analysis of the final reports and found that wood preservatives and insecticide treatments, as well as termite baiting (with fipronil as the active ingredient), are the most commonly used methods. The average cost of managing biological damage was approximately $36,659.36 per heritage site, with a total expenditure of around $12 million over the 10-year period. Our review not only highlights the current treatment protocols and termiticides in use but also addresses ongoing challenges, as well as the regulatory and policy perspectives that should be considered for future termite management strategies.

Based on systematic nationwide surveys conducted between 2019 and 2023, this study provides a nationwide baseline dataset on wasp communities in South Korea. Field collections were conducted across 130 sites, including repeated annual monitoring at 37 primary locations such as Busan, major ports, and the Demilitarized Zone (DMZ) adjacent areas. Fifteen species across three genera were detected, revealing a typical “few dominant–many rare” structure in which six dominant species accounted for 82% of all individuals. The invasive yellow-legged hornet (Vespa velutina nigrithorax) was among the dominant taxa, implying its increasing integration into the native assemblages. Regional comparisons showed the highest relative abundance of V. velutina nigrithorax in Busan, intermediate levels in other ports, and an extremely low abundance in the DMZ adjacent areas, where the Shannon and Simpson indices were highest. Regression analyses showed that the relationships between V. velutina nigrithorax and native species varied by region and year, with positive and negative associations. This suggests context-dependent dynamics of coexistence and competition. Vespula vulgaris was not detected in this study; however, targeted monitoring for early detection remains necessary given its potential invasion risk. Thus, this study underscores the dominance of V. velutina nigrithorax in Korea and emphasizes the contrasting roles of Busan and other ports as invasion gateways and the DMZ adjacent areas as a strategic frontier for early detection. These results provide crucial guidance for region-specific management and the reinforcement of long-term monitoring systems.

Honeybee colonies provide critical pollination services but continue to experience high losses due to multiple stressors. This study developed a simulation framework integrating agricultural resources, urban habitat loss, pesticide stress, and parasite dynamics to examine colony survival under 20,000 parameter scenarios. The mean final survival fraction was 0.77, but the 5th percentile was reduced to 0.48 and reached a minimum of 0.28, indicating that stability at the average conceals severe risks in the distributional extremes. Survival declined abruptly when pesticide lethality exceeded 0.4 and the urban index surpassed 0.7, reflecting nonlinear responses and thresholds that cannot be detected in single-factor analyses. Random Forest and regression models confirmed that pesticide toxicity and habitat degradation were the primary determinants of survival, while pathogen-related variables such as Varroa reproduction contributed minimally. These results indicate that colony persistence is shaped less by gradual declines than by sharp contractions under interacting pressures, and that management strategies focusing mainly on pathogen control may underestimate the destabilizing role of chemical and habitat stressors. Although the model does not capture heterogeneity in pesticide residues, landscape-level foraging variation, or long-term climatic influences, it provides a framework for resilience-oriented risk assessment that emphasizes distributional extremes and nonlinear stressor interactions with direct implications for pollinator management and agroecosystem stability.

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.