Search Results (1,133)

Parasitoid wasps play a fundamental role in the biological control of pests. However, their morphological identification may be limited due to their small size and the high morphological similarity between species. Our objective was to identify specific genomic variants of the target species Palmistichus elaeisis Delvare & LaSalle, 1993, Tetrastichus howardi (Olliff, 1893), Trichospilus diatraeae Cherian & Margabandhu, 1942, and Trichogramma pretiosum Riley, 1879, (Hymenoptera: Chalcidoidea) by whole-genomic sequencing. Parasitoids were collected from their hosts and established in the laboratory after adult emergence. A sample of each parasitoid was sent to the Departamento de Ciências Biológicas at Universidade Federal do Espírito Santo (UFES) and “Oscar Monte” Entomophagous Insect Collection for morphological identification. Subsequently, samples composed of 20 individuals were preserved in absolute ethanol for DNA extraction. The DNA was extracted, quantified and sequenced on the Illumina Novaseq 6000 platform. Bioinformatic tools were used for quality control, detection of specific genomic variants, principal component analysis (PCA), and support vector machine (SVM). Genomic sequencing generated high-quality data for the analyzed parasitoids, allowing the identification of four specific variants for P. elaeisis, two for Te. howardi, four for Ts. diatraeae and five for Tg. pretiosum. These results provide a precise molecular tool for distinguishing parasitoids used in biological control programs. Full article

Outbreaks of emerging and re-emerging diseases in both animals and plants are increasing due to climate change, globalization, land-use change, and agricultural intensification. While most pathogen monitoring programs focus on zoonotic threats, wildlife and other organisms in natural habitats can also serve as reservoirs and sentinels for pathogens of agricultural and ecological concern. Plant communities and the pathogens circulating within them are underrepresented in integrated disease monitoring frameworks. This study demonstrates how biodiversity and zoonosis monitoring programs conducted in protected habitats (tallgrass prairies and woodlands) across Illinois, together with insect specimens preserved in biorepositories, can be leveraged to improve knowledge of the identities and ecological associations of a wide range of potential pathogens. We developed an integrative workflow combining taxonomic identification, molecular screening, and epidemiological inference to detect vector-borne plant pathogens from archived insect material. Focusing on Hemiptera (Auchenorrhyncha), we screened specimens for phytoplasmas (Mollicutes), uncultured bacterial plant pathogens transmitted by sap-feeding insects, and characterized host–pathogen associations. At least three distinct phytoplasma strains were detected: ‘Candidatus Phytoplasma asteris’ (16SrI-B), ‘Candidatus Phytoplasma pruni’-related strains (16SrIII), and ‘Candidatus Phytoplasma sacchari’-related strains (16SrXI-H). The latter represents the first documented occurrence of a 16SrXI-H phytoplasma subgroup in Illinois. Overall, we identified five insect specimens harboring phytoplasmas across four preserved sites, all of which were previously unreported for insect–phytoplasma associations. These findings demonstrate the value of existing biodiversity and zoonosis monitoring infrastructures for proactive surveillance of plant pathogens and extending the One Health paradigm to explicitly include natural ecosystems. Full article

Aedes aegypti is a primary vector for globally significant arboviruses such as dengue virus (DENV). The mosquito’s metavirome, particularly its insect-specific virus (ISV) component, is recognized as a key modulator of arboviral transmission. However, the natural ecology of these interactions in populations remains poorly understood. This study presents the first comparative analysis of the metavirome in wild-caught A. aegypti from Vietnam based on natural DENV infection status. Metaviromic analysis was performed on 69 DENV-positive pools from six central provinces. The results obtained were compared with previously obtained metaviromic data from 7 DENV-negative pools (from the same region). Analysis suggests the presence of a stable ‘core metavirome’ of 11 ISVs present in both groups. Interestingly, six ISVs were detected only in DENV-negative mosquitoes, which may suggest potential antagonistic interactions requiring further investigation. Conversely, five ISVs were found only in DENV-positive pools, including Aedes partiti-like virus 1 and Aedes anphevirus. The latter may suggest possible synergistic relationships that facilitate arboviral replication. Phylogenetic analysis of prevalent ISVs, such as Phasi Charoen-like phasivirus (PCLV) and Chaq-like virus, revealed patterns of both local circulation and genetic diversity. The findings describe distinct ISV profiles associated with DENV infection in a natural setting, providing a data-driven foundation for hypothesizing specific virus–virus interactions. The data underscores the complexity of the mosquito metavirome. Here, we identified several candidate ISVs for future experimental studies aimed at understanding potential functional impact on arboviral vector competence. Full article

Potato purple top is a complex phytoplasma disease that poses a serious threat to potato cultivation worldwide. To verify the presence of different phytoplasma strains in potato disease outbreaks in Iran, six major potato-growing provinces in the central and western regions of the country were surveyed, and a total of 270 potato plants, 230 symptomatic and 40 asymptomatic, was sampled. Nested PCR analysis revealed the phytoplasma presence in 45% of symptomatic and 7% of asymptomatic plants. Molecular analysis was performed, analyzing the sequences of the 16S rRNA gene and the ribosomal protein rp, secY, and tufB genes. Four ‘Candidatus Phytoplasma’ species were identified in the tested potato samples: ‘Ca. P. asteris’ (16SrI-B), ‘Ca. P. tritici’ (16SrI-R), ‘Ca. P. trifolii’ (16SrVI-A), and ‘Ca. P. solani’ (16SrXII-A). The ‘Ca. P. solani’ strains were prevalent, occurring in all the surveyed provinces, whereas the ‘Ca. P. tritici’ strains were restricted to the Chaharmahal and Bakhtiari province. Phylogenetic and multilocus sequence analyses provided a finer resolution, distinguishing among some of the closely related phytoplasma strains. This study represents the first comprehensive molecular survey of potato-infecting phytoplasmas across a wide geographical region of Iran. The findings will aid studies regarding insect vector(s), pathogen biology, host range and disease management strategies. Full article

The management of Culex pipiens (Diptera: Culicidae), key vectors of arboviruses like West Nile virus, necessitates sustainable alternatives to chemical insecticides. This study screened indigenous entomopathogenic fungi (EPF) from forest soils in Achaia, Greece, for their larvicidal efficacy against Cx. pipiens biotype molestus. Fifteen fungal isolates were obtained via insect baiting and identified as Beauveria and Metarhizium species. A comprehensive bioassay at 1 × 10⁸ conidia mL⁻¹ revealed significant variation in pathogenicity after 72 h. Two isolates, Beauveria bassiana (BB) (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae (K3(1)) (Hypocreales: Clavicipitaceae), exhibited the highest virulence among the tested isolates, each causing 60% mortality with a rapid median lethal time (LT₅₀) of ~18.5 h. Survival analysis, Cox modeling, and non-linear kinetic modeling (Gompertz/Richards) classified three distinct virulence clusters: high/rapid, moderate/consistent, and low/delayed. A pathogenicity network analysis and a composite virulence index further validated BB and K3(1) as the most effective candidates. These results demonstrate the high isolate specificity of fungal efficacy and underscore the importance of screening local fungal diversity. The identified high-virulence isolates represent promising, environmentally sound candidates for the development of targeted biopesticides. Future research should focus on formulation for aquatic environments and integration into resistance-resilient integrated vector management programs. Full article

Sesame is an oilseed crop threatened by a phyllody disease associated with the presence of phytoplasmas, which can reduce yields by up to 80%. The molecular identification of these bacteria in crops located in Western Iran was achieved from samples showing symptoms of diverse intensity and types. For biological characterization, the pathogen was also dodder-transmitted to periwinkle plants. After nucleic acid extraction and nested PCR using phytoplasma-specific primer pairs amplifying part of the 16S rRNA gene, it was possible to amplify DNA fragments from both symptomatic sesame samples and dodder-inoculated periwinkle plants. The virtual RFLP pattern from the 16S rRNA gene sequences using iPhyClassifier indicated the presence of phytoplasma strains in 16SrII-D and 16SrIX-C subgroups. The identity percentage values of the obtained amplified sequences corroborated by the phylogenetic analysis identified them as ‘Candidatus Phytoplasma australasiaticum’ and ‘Ca. P. phoenicium’, respectively. The two phytoplasma strains were detected in different sesame samples collected in the same field. The coexistence of two phytoplasmas may influence the observed differences in disease severity and suggests appropriate management strategies, since diverse insect vectors were reported alongside diverse phytoplasmas associated with this disease. Moreover, the widespread disease presence strongly suggests the breeding of resistant varieties. Full article

The overuse of chemical insecticides highlights the urgent need for novel vector control strategies. Insect-specific viruses (ISVs), such as the cell-fusing agent virus (CFAV), have shown potential to block arbovirus transmission by inhibiting viral replication in mosquitoes. However, the effects of CFAV beyond its natural host, Aedes aegypti, remain largely unexplored. In this study, we established a CFAV infection model in Aedes albopictus, a major vector for Zika virus (ZIKV), via intrathoracic injection. Stable infection was achieved, with viral loads reaching up to 10⁷ copies per mosquito by day 10 post-injection. Nevertheless, high post-injection mortality (median survival: 3 days) was observed, which we attribute primarily to mechanical injury. No evidence of vertical transmission of CFAV was detected in Ae. albopictus. Co-injection of CFAV and ZIKV did not significantly affect ZIKV replication in this species. In contrast, in Ae. aegypti pre-infected with CFAV followed by oral ZIKV challenge, CFAV significantly reduced ZIKV infection rates in the ovaries at day 4 and viral loads in salivary glands at day 10. These findings demonstrate that while CFAV can productively infect Ae. albopictus, it does not undergo vertical transmission in this species, and has no inhibitory effect on ZIKV under the co-infection conditions tested. This study underscores challenges associated with using single ISVs such as CFAV for arbovirus control and highlights the complex, bidirectional role of multiple ISV co-infections. While exploring multi-ISV combinations may offer a potential strategy to enhance antiviral efficacy, their net effect—whether suppression or enhancement of arboviruses—warrants careful investigation. Full article

Dendroctonus armandi is a major primary pest of Chinese white pine in the Qinling–Bashan forest region. By feeding on the phloem and vectoring symbiotic fungi that cause blue stain in the sapwood, it drives rapid decline and mortality of host trees. As a key wood-boring forest insect, its outbreaks are closely linked to adaptive strategies in energy metabolism. Adipokinetic hormone (AKH) is a highly conserved insect neuropeptide and plays a major role in regulating energy metabolism. This study aimed to determine how the AKH gene regulates energy use in D. armandi under different stress conditions. We cloned the DaAKH gene and its receptor gene, DaAKHR, from D. armandi. DaAKH and DaAKHR showed the highest expression in emerged adults and the lowest levels in pupae. In larvae and in adult males and females, DaAKH transcripts were predominantly expressed in the head, whereas DaAKHR was enriched in the fat body. Under starvation and cold stress, DaAKH and DaAKHR expression were significantly upregulated; under heat stress, expression first increased and then decreased. Across stress treatments, RNAi significantly downregulated DaAKH and DaAKHR expression in D. armandi. Under starvation, RNAi reduced mortality, lowered lipid metabolism, and led to lipid accumulation, thereby mitigating premature energy depletion and starvation-induced death. By contrast, under heat and cold stress, RNAi significantly increased mortality, significantly reduced triglyceride and glycogen consumption, and suppressed metabolism. These results indicate that DaAKH and DaAKHR regulate energy allocation under starvation stress and help maintain adaptive capacity under temperature stress in D. armandi. By tuning energy metabolism, DaAKH and DaAKHR help resist environmental stress and maintain reproduction and population size. This study advances understanding of the physiological responses and molecular mechanisms of D. armandi under stress conditions and provides a new avenue for metabolism-targeted control. Full article

In this study, we propose a compartmental mathematical model that considers two interacting populations (citrus plants and insect vectors) and investigate the transmission dynamics of Huanglongbing in citrus crops. This disease is caused by the bacterium Candidatus Liberibacter asiaticus and is vectored by the psyllid Diaphorina citri. The disease is modeled under the following three main assumptions: there is vital dynamics with constant recruitment rates of citrus plants, the force of infection in both populations is a spatially dependent function varying with geographic location, and there is a spatial displacement of the vectors. In the main results of the paper, we formulate a coupled ordinary and partial differential equation system with initial and zero flux boundary conditions, establish the existence and uniqueness of solutions to the proposed model by applying semigroup theory, and introduce a numerical approximation of the system. Moreover, we develop a stability and persistence analysis. From the analytical point of view, we calculate the basic reproduction number $R_0$ and prove three facts: the disease-free equilibrium is globally asymptotically stable when $R_0<1$; the disease-free equilibrium is globally asymptotically stable when $R_0>1$; and the hybrid system exhibits uniform persistence of infection when $R_0>1$. In addition, we present some numerical examples. Full article

Chagas disease, caused by Trypanosoma cruzi, is maintained in nature by complex interactions among wild vertebrates and triatomine insect vectors, yet the role of many introduced hosts remains poorly resolved. Here, we assessed natural T. cruzi infection in wild European rabbits (Oryctolagus cuniculus) from central Chile, where introduced rabbits overlap ecologically with the sylvatic vector Mepraia spinolai. Eight free-ranging rabbits captured in Las Chinchillas National Reserve were evaluated using an integrative diagnostic approach combining xenodiagnosis with laboratory-reared, parasite-free M. spinolai nymphs, real-time polymerase chain reaction targeting T. cruzi satellite DNA in blood and 12–14 organs per animal, and histopathology with immunohistochemistry (anti-cruzipain) to identify tissue parasite forms. Blood molecular detection was positive in seven out of eight rabbits, while xenodiagnosis detected viable parasites in two out of seven evaluated individuals. Organ molecular screening detected T. cruzi DNA in at least one organ in all rabbits, with frequent positivity in the diaphragm, reproductive tissues, spleen, and kidney. Histopathology identified parasite forms in four out of eight animals, and immunohistochemistry confirmed hepatic amastigotes in one case. These findings provide multi-method evidence of natural infection in the sampled individuals, including evidence of parasite viability in some individuals, suggesting potential epidemiological relevance within this ecological context and possible utility for surveillance in Chilean sylvatic transmission settings. Full article

Oxidative stress induced by reactive oxygen species (ROS) is a major contributor to senescence. Although strategies to mitigate ROS are considered crucial for reversing this process, effective interventions remain limited. Extracts from Polygonum cuspidatum (P. cuspidatum) have shown protective effects against senescence by suppressing mitochondrial ROS production; however, the specific bioactive compound responsible for these effects has not yet been identified. This study aimed to identify the active compound in P. cuspidatum responsible for reducing mitochondrial ROS and to elucidate its mechanism of action in rejuvenating senescence. Bioactive components of P. cuspidatum extract were screened for their ability to decrease mitochondrial ROS production. The most potent compound, 2-methoxystypandrone (2-MS), was further examined for its effects on oxidative phosphorylation (OXPHOS) efficiency, mitochondrial ROS generation, and senescence-associated phenotypes in a skin cell-based model. 2-MS was identified as the most effective compound for reducing mitochondrial ROS. Mechanistically, 2-MS enhanced OXPHOS efficiency, thereby minimizing ROS production resulting from inefficient respiration. Reduction in mitochondrial ROS by 2-MS restored senescence-associated phenotypes and rejuvenated senescence by suppressing ROS-driven melanogenesis and inflammatory responses in skin cells. This study identifies 2-MS as a key active ingredient of P. cuspidatum that exerts anti-aging effects through the reduction in mitochondrial ROS generation. These findings highlight 2-MS as a promising therapeutic and cosmetic candidate for rejuvenating senescence. Full article

Insect bites are a common cause of skin irritation and can contribute to disease transmission through vector-borne pathogens. Early identification of the likely biting organism can assist preliminary guidance (e.g., monitoring for warning signs, considering exposure history) and may reduce complications through timely follow-up. This paper studies a compact attention-guided learning framework for multiclass insect-bite image classification under strict storage constraints. A teacher network (BiteAI-T) based on MobileNetV3-Small is trained with spatial attention pooling to emphasize lesion-relevant regions while maintaining an efficient backbone. A lightweight depthwise-separable student (BiteAI-S) is trained using multi-level knowledge distillation that combines softened-logit matching with intermediate supervision through attention-map alignment and pooled-feature matching. Model storage is further reduced through weight-only quantization-aware training using an LSQ-inspired learnable scaling factor; BatchNorm running statistics are frozen during quantization fine-tuning to improve stability. Experiments on an eight-class dataset (ants, bed bugs, chiggers, fleas, mosquitos, no bites, spiders, ticks) show that BiteAI-T reaches 93.75% test accuracy. For deployment, we export (i) a TorchScript Lite teacher artifact (BiteAI-T_Lite, 2.35 MB) and (ii) a weight-only int8 student artifact (BiteAI-S_int8, 0.992 MB). Comparative results are also reported for an SVD-compressed + fine-tuned FP16 variant (92.66% test accuracy, 2.84 MB), illustrating accuracy–size trade-offs across compression strategies. Full article

Chrysomya megacephala is a synanthropic fly with a high potential to act as a mechanical vector of pathogenic bacteria, surpassing Musca domestica in both bacterial load and diversity. Native to Asia and Africa, it has become a cosmopolitan species, successfully adapting to a wide range of environments, including natural ecosystems. In Colombia, studies on its role as a vector are limited and have largely relied on traditional culturing methods. This study aimed to characterize the pathogenic bacterial microbiota associated with C. megacephala using 16S rRNA gene sequencing in urban, rural, and forest settings of a coastal tourist city. Flies were collected using Van Someren Rydon traps with attractants and sterile materials. Bacterial identification was performed through Oxford Nanopore MinION sequencing (Manufactured by Oxford Nanopore Technologies, Oxford, UK). A total of 49 bacterial species were identified, with urban environments showing the highest taxonomic richness. The forest environment was characterized by a highly dominant community structure, led by Vagococcus carniphilus. Notably, 20 bacterial species of public health relevance were detected, including Clostridium botulinum, Clostridium perfringens, Ignatzschineria ureiclastica, Escherichia coli, and Streptococcus agalactiae. These findings indicate that bacterial community composition varies by environment and underscore the potential role of C. megacephala as a mechanical vector, highlighting the importance of surveillance for its public health implications. Full article

Background/Objectives: Epidemiological studies have proven that coxsackievirus B3 (CVB3) is the major virus that causes acute and chronic myocarditis and pancreatitis. Currently, there are no antiviral therapeutic drugs or vaccines that are available for use as clinical therapeutics or vaccines. Subunit polypeptides-based vaccines, especially when combined with adjuvants, represent safe and effective vaccine platforms because they are considered to be better immunogens. The viral capsid protein VP1 of CVB3 is the most immunogenic viral polypeptide, providing opportunities for its use in designing subunit polypeptide vaccines. In the present study, we designed and produced a CVB3 vaccine candidate based on the recombinant expression of the major immunogenic viral protein VP1 of a wild-type CVB3 strain. Methods: We assessed its induced humoral and cellular immune responses and then evaluated its protective immunity against pathogenic CVB3 strain challenges in a Balb/c mouse model. Neutralizing specific antibodies and cytokine interferon gamma (INF-γ) production were determined in the sera of both prime- and prime-boost-immunized mice with the vaccine candidate. Results: Our results demonstrate that the recombinant rVP1 expressed in a eukaryotic insect cell baculovirus vector system elicited cellular and humoral immune responses, protecting Balb/c mice from lethal challenges. Conclusions: Hence, the vaccine produced based on the recombinant expression of VP1 is a promising and potential candidate against natural CVB3 infections. Full article

(1) Since its introduction to China, pine wilt disease (PWD) has caused severe damage to coniferous forests in affected regions. The disease continues to expand northwestward, posing a significant threat to the ecological security of Xinjiang. (2) This study employed the maximum entropy (MaxEnt, version 3.4.4) model to predict potential areas for PWD transmission and suitable habitats for its vector insect, Monochamus saltuarius (Gebler, 1830). By integrating these results, the potential occurrence areas of PWD in Xinjiang were identified. (3) Human activities were the primary drivers of PWD spread, with factors related to scenic areas and overall human influence playing key roles. Altitude and isothermality were the main limiting factors for the vector insect. Potential PWD occurrence areas were identified, covering approximately 88% of the total coniferous forest area in Xinjiang. (4) High-risk regions include Urumqi City, Ili Kazakh Autonomous Prefecture, and Altay Prefecture. This study clarifies potential transmission routes and analyzes high-risk areas, providing a scientific basis for forestry authorities to implement targeted prevention and control measures. Full article