Investigating the Influence of Varied Light-Emitting Diode (LED) Wavelengths on Phototactic Behavior and Opsin Genes in Vespinae.

The phototactic behavior of insects is commonly used to manage pest populations in practical production. However, this elusive behavior is not yet fully understood. Investigating whether the opsin genes play a crucial role in phototaxis is an intriguing topic. Vespinae (Hymenoptera: Vespidae) are a common group of social wasps that are closely associated with human activities. Efficiently controlling wasp populations while maintaining ecological balance is a pressing global challenge that still has to be resolved. This research aims to explore the phototactic behavior and key opsin genes associated with Vespinae. We found significant differences in the photophilic rates of Vespula germanica and Vespa analis under 14 different light conditions, indicating that their phototactic behavior is rhythmic. The results also showed that the two species exhibited varying photophilic rates under different wavelengths of light, suggesting that light wavelength significantly affects their phototactic behavior. Additionally, the opsin genes of the most aggressive hornet, Vespa basalis, have been sequenced. There are only two opsin genes, one for UV light and the other for blue light, and Vespa basalis lacks long-wavelength visual proteins. However, they exhibit peak phototaxis for long-wavelength light and instead have the lowest phototaxis for UV light. This suggests that the visual protein genes have a complex regulatory mechanism for phototactic behavior in Vespinae. Additionally, visual protein sequences have a high degree of homology among Hymenoptera. Despite the hypotheses put forward by some scholars regarding phototaxis, a clear and complete explanation of insect phototaxis is still lacking to date. Our findings provide a strong theoretical basis for further investigation of visual expression patterns and phototactic mechanisms in Vespinae.

Managing systemic reactions and venom immunotherapy in vespid-venom allergy: observations from a retrospective study of Portuguese patients.

Summary: Background. Vespula spp. and Polistes spp. are relevant species in South Europe, with Vespa velutina nigrithorax (VVN) being considered a public health problem. We aimed to characterize a cohort of Portuguese patients referred for large local reaction (LLR) and/or systemic reaction (SR) to vespids. In patients treated with venom immunotherapy (VIT), induction protocol and frequency of adverse reactions were evaluated. Methods. Retrospective study including patients with LLR and SR to vespids referred to our Immunoallergology Department (2008-2022). Results. A total of 129 patients were evaluated, the majority were male adults (n = 77, 59.7%), from rural areas. From these, 51 patients had SR (Mueller classification: 7.8% grade I, 19.6% grade II, 37.3% grade III, 35.3% grade IV). We found no differences regarding the levels of total serum IgE, basal serum tryptase value, sIgE levels to the eliciting venom or their molecular components, regarding the severity of the SR that motivated the referral to our clinic. In the SR group, previous LLR Hymenoptera sting were reported in 15.7%. Thirty-eight patients (74.5%) initiated VIT: 22 with wasp venom, 14 with paper wasp venom and 2 with Vespa velutina venom. There was one mild systemic reaction, not requiring adrenaline and 4 LLR. Re-stings after VIT occurred in 16 patients, without any systemic or local reactions. Currently, eleven patients remain under VIT. Conclusions. Most vespid-venom allergic patients are male adults from rural areas. Sensitization to wasp venom was present in 52.9%, paper wasp in 33.3% and Vespa velutina in 13.7%. The frequency of adverse reactions during both induction and maintenance phases appears to be low. Despite a reduced sample size, our experience with VVN VIT, suggests its safety.

Body Size of Female Strepsipteran Parasites (Strepsiptera, Xenidae, Xenos) Depends on Several Key Factors in a Vespine Wasp (Hymenoptera, Vespidae, Vespa).

Parasite growth in hosts depends on their hosts' nutritional status. This study examined whether the body size of the strepsipteran parasite Xenos oxyodontes, which parasitizes the eusocial wasp Vespa analis, is affected by several key factors, including host body size. We collected V. analis using bait traps for three years in Niigata, Japan, and evaluated the number of male and female X. oxyodontes parasites throughout the seasons. A total of 185 female parasites were collected, and their cephalothorax widths were measured. The widths of female parasites did not statistically vary among seasons and were positively correlated with the head widths of female host wasps but negatively correlated with the number of parasites per host wasp. In addition, we examined whether the reproductive conditions of post-hibernation solitary queens affected the cephalothorax width of female parasites. The widths of the female parasites were greater when the queens had less-developed ovaries. These results suggested that nutrient availability by female parasites depends on the host wasp and competition with conspecific individuals.

Peeking into the Stingers: A Comprehensive SWATH-MS Study of the European Hornet Vespa crabro (Linnaeus, 1758) (Hymenoptera: Vespidae) Venom Sac Extracts.

This study aimed to investigate the venom sac extracts (VSEs) of the European hornet (EH) Vespa crabro (Linnaeus, 1758) (Hymenoptera: Vespidae), focusing on the differences between stinging females, gynes (G), and workers (W), at the protein level. Using a quantitative "Sequential Window Acquisition of all Theoretical Fragment Ion Mass Spectra" (SWATH-MS) analysis, we identified and quantified a total of 240 proteins. Notably, within the group, 45.8% (n = 110) showed significant differential expression between VSE-G and VSE-W. In this set, 57.3% (n = 63) were upregulated and 42.7% (n = 47) downregulated in the G. Additionally, the two-hundred quantified proteins from the class Insecta belong to sixteen different species, six of them to the Hymenoptera/Apidae lineage, comprising seven proteins with known potential allergenicity. Thus, phospholipase A1 (Vesp v 1), phospholipase A1 verutoxin 2b (VT-2b), hyaluronidase A (Vesp v 2A), hyaluronidase B (Vesp v 2B), and venom allergen 5 (Vesp v 5) were significantly downregulated in the G, and vitellogenin (Vesp v 6) was upregulated. Overall, 46% of the VSE proteins showed differential expression, with a majority being upregulated in G. Data are available via ProteomeXchange with identifier PXD047955. These findings shed light on the proteomic differences in VSE between EH castes, potentially contributing to our understanding of their behavior and offering insights for allergy research.

Shotgun metagenomics reveals the gut microbial diversity and functions in Vespa mandarinia (Hymenoptera: Vespidae) at multiple life stages.

Wasps play important roles as predators and pollinators in the ecosystem. The Jingpo minority residing in Yunnan Province, China, has a traditional practice of using wine infused with mature wasps as a customary remedy for managing rheumatoid arthritis. The larva of the wasp is also a tasteful folk dish that has created a tremendous market. There is a paucity of survival knowledge, which has greatly restricted their potential applications in food and healthcare. Recent research has highlighted the importance of gut microbiota in insect growth. Nevertheless, there is still a lack of understanding regarding the composition, changes, and functions of the gut microbiota in Vespa mandarinia during development. In this research, the gut microbiota were investigated across three growth stages of Vespa mandarinia using a metagenomic technology. The result revealed that there are significant variations in the proportion of main gut microbes during the metamorphosis of Vespa mandarinia. Tenericutes were found to dominate during the larval stage, while Proteobacteria emerged as the dominant group post-pupation. Through a comprehensive analysis of the gut microbiota metagenome, this study revealed functional differences in the wasp gut microbiota at various growth stages. During the larval stage, the gut microbiota plays a central role in promoting metabolism. Following pupation, the gut microbiota exhibited diversified functions, likely due to the complex environments and diverse food sources encountered after metamorphosis. These functions included amino acid metabolism, compound degradation, and defense mechanisms. This research provides an extensive dataset on the gut microbiota during the metamorphosis of Vespa mandarinia, contributing to a deeper understanding of the influence of gut microbiota on wasp growth. Furthermore, this study uncovers a unique microbial treasure within insect guts, which is important for advancing the application of wasps in the fields of food and medicine.

Molecular Characterization and Phylogenetic Analysis of Flightin Gene in Vespa basalis (Hymenoptera, Vespidae).

Flight is a complex physiological process requiring precise coordination of muscular contraction. A key protein in insect flight is flightin, which plays an integral role in the flight muscles. This research sought to evaluate the flight competence of the social wasp V. basalis by characterizing the molecular components involved. Our study focused on Vespa basalis, one of the most dangerous hornet species, utilizing PCR to obtain a partial cDNA sequence of the flightin protein. We then employed phylogenetic and sequence analysis to gain insights into this protein in flight-related adaptations. The cDNA has an 1189-base pair sequence including an open reading frame (453 bp) encoding 150 amino acids. Analyzing the deduced amino acid sequence using an online tool revealed a molecular weight of 18.05 kDa, an isoelectric point of 5.84, four functional site patterns, and no transmembrane topology. We constructed a phylogenetic tree of flightin based on 38 species. Our analysis indicated that V. basalis is most closely related to V. mandarinia; this alignment is consistent with their similar aggressive behavior, but their evolutionary relationship, based on mitochondrial sequences, presents a contrast. These initial findings on the flightin gene in V. basalis lay the groundwork for future functional studies to elucidate its specific role in flight adaptations and explore its potential as a target for pest management strategies.

Phylogeographic Reconstruction to Trace the Source Population of Asian Giant Hornet Caught in Nanaimo in Canada and Blaine in the USA.

The Asian giant hornet, Vespa mandarinia, is an invasive species that could potentially destroy the local honeybee industry in North America. It has been observed to nest in the coastal regions of British Columbia in Canada and Washington State in the USA. What is the source population of the immigrant hornets? The identification of the source population can shed light not only on the route of immigration but also on the similarity between the native habitat and the potential new habitat in the Pacific Northwest. We analyzed mitochondrial COX1 sequences of specimens sampled from multiple populations in China, the Republic of Korea, Japan, and the Russian Far East. V. mandarinia exhibits phylogeographic patterns, forming monophyletic clades for 16 specimens from China, six specimens from the Republic of Korea, and two specimens from Japan. The two mitochondrial COX1 sequences from Nanaimo, British Columbia, are identical to the two sequences from Japan. The COX1 sequence from Blaine, Washington State, clustered with those from the Republic of Korea and is identical to one sequence from the Republic of Korea. Our geophylogeny, which allows visualization of genetic variation over time and space, provides evolutionary insights on the evolution and speciation of three closely related vespine species (V. tropica, V. soror, and V. mandarinia), with the speciation events associated with the expansion of the distribution to the north.

Effects of wasp (Vespa crabro) nest extracts on virus replication of Autographa californica nuclear polyhedrosis virus on Spodoptera frugiperda cell culture.

The antiviral properties of the extracts of Vespa crabro nests collected from the Black Sea, Turkey have been investigated on Spodoptera frugiperda (Sf) cell cultures of Autographa californica multicapsid nuclear polyhedrosis virus (AcMNPV). The effect of nests on cell viability and cytotoxicity analysis and the antiviral assay was studied, and the cytopathic effects of the virus were detected. The nest's viral content was identified. The impact of nest extracts on the protein synthesis of the virus was investigated. Also interaction with pUC18 plasmid DNA was investigated, to analyse the protective effects of the Vespa crabro nest extract againist to hydroxyl radical-mediated DNA damage. 50 µg/ml concentration of ethanol, acetone, and petroleum ether extracts of the nests reduced the cytopathic effects of baculovirus on Sf cells. The extracts delayed infection above 25 µg/ml concentration. When the effects of nest extracts on virus titer were evaluated; the 50 µg/ml concentration of the acetone extract of the nest showed the highest effect (75%) reducing the virus titer. 25 µg/ml concentration of the ethanol extract of the nest showed the lowest effect (33.33%) with a reduction. The presence of polyhedrin protein was observed at 25 µg/ml concentrations of acetone and petroleum ether extracts. When the potential of the nest extracts to repair DNA damage, the nest extracts were found to have a concentration-dependent repair feature in different applications. As a result of bioactive component analysis, (Z) 9-Tricosane and (cis)-2-nonadecene (1.65%) were found to have the highest % areas. In other respects, 1H-Purine-6-amine, 2-dodecanol and hexadecanoic acid compaunds were Additionally, 1H-Purine-6-amine, 2-dodecanol and hexadecanoic acid compounds, which are associated with antiviral activity, also determined in the biocomponent analysis. Supplementary Information: The online version contains supplementary material available at 10.1007/s10616-023-00603-0.

Evaluation of the Cytokine Response Induced by Specific Allergen Immunotherapy in Patients with Vespa velutina Anaphylaxis.

INTRODUCTION: Changes in the cytokine profile from type 2 to type 1 together with the induction of regulatory cells are expected during hymenoptera venom immunotherapy (VIT). The present study was aimed to investigate the changes in type 1, type 2, and regulatory cytokines induced by a Vespula spp. VIT in patients with anaphylaxis to Vespa velutina. METHODS: Twenty consecutive patients with anaphylaxis due to Vespa velutina were treated with Vespula spp. VIT. Serum cytokines (IL-4, IL-5, IL-10, IL-13, and IFN-É£) were measured at baseline, 6, and 12 months after starting VIT. RESULTS: A significant increase in serum IFN-y was detected after 6 and 12 months of VIT. An increase in serum IL-10 and a decrease in IL-5 were observed after 12 months. IL-4 was undetectable all along the study, and an unexpected increase of IL-13 was present at 12 months of treatment. CONCLUSION: Vespula spp. VIT seems to be able to induce a shift to type 1 cytokine production measured through IFN-y levels and IL-10 production after, at least, 6 and 12 months of VIT, respectively.

[Insect venom allergies-What will change in times of global change?] / Insektengiftallergien ­ Was wird sich ändern in Zeiten des globalen Wandels?

BACKGROUND: In Germany, honeybees (Apis mellifera) and various Vespula species (wasps) are primarily relevant for hypersensitivity reactions to stings. Hornets (Vespa crabro), bumblebees, paper wasps (Polistes) and yellowjackets (Dolichovespula) less frequently cause sting reactions. OBJECTIVE: What effects do intensive agricultural utilization and climate change have on the living conditions and occurrence of Hymenoptera and what consequences do they have for the diagnostics and treatment of hypersensitivity reactions to Hymenoptera stings. MATERIAL AND METHODS: A literature search was carried out. RESULTS: Honeybees and wild bees are endangered due to introduced diseases, invasive species and pesticides. The aim of widespread beekeeping activity is to protect honeybees, which is why no reduction in stings is to be expected despite increased bee mortality. In Germany, there is evidence of the spread of thermophilic Polistes species (paper wasps) from south to north and the immigration of Vespa velutina nigrithorax (Asian hornet). It is unlikely that these species will lead to a significant increase in sting reactions. Nests of the red fire ant (Solenopsis invicta), which was originally common in South America, were first detected in Sicily in 2022. Red fire ants are aggressive insects with a high potential for adverse sting reactions. CONCLUSION: Invasive insects must be considered as a trigger in the anamnesis and diagnostics. Diagnostics are only available for the detection of Polistes sensitization. Therapeutic allergens can be obtained from other European countries for venom immunotherapy of a Polistes allergy. Due to cross-reactivity, diagnostic and therapeutic allergens from Vespula spp. are used for the diagnosis and treatment of suspected allergies to the Asian hornet.

The oriental hornet (Vespa orientalis) as a potential vector of honey bee's pathogens and a threat for public health in North-East Italy.

BACKGROUND: Oriental hornets are large predatory hymenoptera that occur in the southern part of Asia and the southeastern Mediterranean. Among many pests of bee colonies, Vespa orientalis was recorded to be one of the most destructive. OBJECTIVES: The aim of this study was to: (1) monitor the presence of pathogens carried by V. orientalis that could potentially threaten honey bees and public health; (2) describe the hornet's predatory behavior on honey bee colonies and (3) collect the medical history of a V. orientalis sting suffered by a 36-year-old woman. METHODS: Observations of V. orientalis predatory behavior and the catches of hornets for parasitological and microbiological examination, using molecular and bacteriological analyses, were carried out in three experimental apiaries, both in spring in order to capture the foundress queens and during the summer to capture the workers. Furthermore, the medical history and photographic documentation of a V. orientalis sting suffered by a 36-year-old woman have been collected. RESULTS: The results obtained highlight that V. orientalis is capable of causing serious damage to beekeeping by killing bees, putting under stress the honey bee colonies and by potentially spreading honey bee pathogens among apiaries. These hornets may also become a public health concern, since they are capable of inflicting multiple, painful stings on humans. CONCLUSIONS: Only the development of an Integrated Management Control Program will be able to contain the negative effects of anomalous population growth and the potentially negative impact on honey bees and public health of V. orientalis.

Hymenoptera Allergy Diagnosis through Their Presence on Human Food.

Venom immunotherapy (VIT) protects up to 98% of treated Hymenoptera allergy patients from reactions with new stings. A correct diagnosis with the identification of the venom causing the allergic reaction is essential to implementing it. The knowledge of the Hymenoptera foraging habits when the sting takes place in a food environment would allow the culprit insect to be known. Images of Hymenoptera occurring in environments where there was human food were recorded in Spain, including the date of the image, the place description and its geolocation. The insects' genus and species were identified by an entomologist. Results: One hundred and fifty-five images depicting 71 insects were analyzed. The identified insects were Vespula (56), Vespa (7), Polistes (4), Cerceris (2), Bombus (1) and Apis (1). Most (97.1%) of the images were obtained in summer and early autumn, outdoors in terraces (64%). Meat was the food associated with 47.9% of the images. In protein-rich foods, Vespula was found in 89%. Conclusions: Vespula was the main Hymenoptera associated with food environments in our country (78.87%), and in most of the cases (71%), the food involved is a source of protein, such as meat or seafood. In that environment, the probability that the insect is a Vespula would be 89%.

Investigating the Architecture and Characteristics of Asian Hornet Nests: A Biomimetics Examination of Structure and Materials.

This study investigates the internal architecture of Asian hornet nests (AHNs) using advanced imaging techniques, such as CT scanning and X-ray radiography, to understand their construction and function. The primary objective and significance of this study centre on drawing inspiration from the creative way Asian hornets construct their nests, with a particular focus on the architecture, design, functionality, and building materials of these nests. The architectural principles governing the construction of these nests, such as the arrangement of hexagonal cells, pedicels for load bearing, and adhesive materials, serve as a source of inspiration for innovative and sustainable design practices. The pedicels in Asian hornet nests play a crucial role in transferring load and ensuring stability. Additionally, AHNs' adhesion to tree branches is essential for preventing collapse, and the pedicels provide necessary structural support. The knowledge gained from studying AHNs' internal architecture could be applied directly to the architecture and civil engineering fields to improve structure stability and durability. The microstructure analysis of the paper-like material that hornets produce to build their nests indicates a complex and heterogeneous structure, composed of various plant fragments and fibres. This unique composition creates intricate grooves and pores, which are essential for regulating temperature and humidity levels within the outer envelope of the nest. The study of Asian hornet nests' internal structure demonstrated that nature's engineering principles inspire the design of durable and resilient structures in the construction industry. Civil engineers can incorporate similar principles into their designs to enhance the structural integrity and performance of buildings, bridges, and other infrastructure.

Structural Similarities, in Relation with the Cross-Reactivity, of Hymenoptera Allergenic Dipeptidyl Peptidases IV-An Overall Comparison Including a New Dipeptidyl Peptidase IV Sequence from Vespa velutina.

(1) Background: Dipeptidyl Peptidases IV (DPPIVs), present in many organisms, are minor components in the venoms of Hymenoptera, where they have been identified as cross-reactive allergenic molecules. Considering that the structure of homologous DPPIVs is well characterized, we aimed to explain which regions have higher similarity among these proteins and present a comparison among them, including a new Vespa velutina DPPIV sequence. Moreover, two cases of sensitization to DPPIVs in wasp- and honeybee-sensitized patients are presented. (2) Methods: Proteomic analyses have been performed on the venom of the Asian hornet Vespa velutina to demonstrate the sequence of its DPPIV (allergen named Vesp v 3, with sequence accession number P0DRB8, and with the proteomic data available via ProteomeXchange with the identifier PXD046030). A comparison performed through their alignments and analysis of the three-dimensional structure showed a region with higher similarity among Hymenoptera DPPIVs. Additionally, ImmunoCAP™ determinations (including specific inhibition experiments), as well as IgE immunoblotting, are performed to demonstrate the allergenicity of Api m 5 and Ves v 3. (3) Results and Conclusions: The data presented demonstrate that the similarities among Hymenoptera DPPIVs are most likely localized at the C-terminal region of these enzymes. In addition, a higher similarity of the Vespa/Vespula DPPIVs is shown. The clinical cases analyzed demonstrated the allergenicity of Api m 5 and Ves v 3 in the sera of the allergic patients, as well as the presence of this minor component in the preparations used in venom immunotherapy.

Describing the Pollen Content in the Gastrointestinal Tract of Vespa velutina Larvae.

Vespa velutina is an invasive species that exhibits flexible social behavior, which may have contributed to its introduction in several European countries. It is important to understand its behavior in order to combat the effects of its introduction in different areas. This implies knowing the resources that it uses during its biological cycle. Hornets require protein resources taken from insects and organic matter as well as carbohydrates as an energy source to fly and also to forage for food and nest-building materials. The gastrointestinal tract of adults and larvae contains a wide variety of pollen types. The identification of this pollen in larvae collected from nests could offer information about the plant species that V. velutina visits as a foraging place. The main objective of this research was to study the pollen content in the gastrointestinal tract of larvae. Patterns of pollen content and pollen diversity were established according to the nest type, altitude, season, and location in the nest comb. The abundance of pollen types such as Eucalyptus, Castanea, Foeniculum vulgare, Hedera helix, Taraxacum officinale, Echium, or Cytisus pollen type stands out in many of the samples.

The threat of honey bee RNA viruses to yellow-legged hornets: Insights from cross-species transmission events.

Viral diseases are a significant challenge in beekeeping, and recent studies have unveiled a potential link between these diseases and the yellow-legged hornets (Vespa velutina), notorious predators of honey bees. However, it remains unclear whether virus diseases are commonly shared between honey bees and hornets or are merely sporadic cross-species transmission events. To address this knowledge gap, we conducted a study utilizing hornet-keeping practices in Yunnan, Southwest China. Our findings demonstrate that deformed wing virus (DWV-A) and Israeli acute paralysis virus (IAPV) can be transmitted from honey bees to yellow-legged hornets. We detected virus replication in various hornet stages, including pupae with IAPV infections, indicating the similarities between infected hornet and honey bee stages. Furthermore, we observed signs and infection intensities of DWV-A and IAPV comparable to those in honey bees. While different polymorphisms were found in the virus isolates from yellow-legged hornets, the sequences remain similar to honey bee counterparts. While our findings suggest that DWV-A and IAPV behave like common diseases, we observed a natural elimination of the viruses in hornet colonies, with minimal alterations in viral sequences. Consequently, these events appear to be cross-species transmission from honey bees, with yellow-legged hornets acting as potential incidental hosts. Further investigations of virus monitoring in hornets promise valuable insights into the disease ecology of bee-infecting viruses.

A Designed Analog of an Antimicrobial Peptide, Crabrolin, Exhibits Enhanced Anti-Proliferative and In Vivo Antimicrobial Activity.

Antimicrobial peptides have gradually attracted interest as promising alternatives to conventional agents to control the worldwide health threats posed by antibiotic resistance and cancer. Crabrolin is a tridecapeptide extracted from the venom of the European hornet (Vespa crabro). Its antibacterial and anticancer potentials have been underrated compared to other peptides discovered from natural resources. Herein, a series of analogs were designed based on the template sequence of crabrolin to study its structure-activity relationship and enhance the drug's potential by changing the number, type, and distribution of charged residues. The cationicity-enhanced derivatives were shown to have improved antibacterial and anticancer activities with a lower toxicity. Notably, the double-arginine-modified product, crabrolin-TR, possessed a potent capacity against Pseudomonas aeruginosa (minimum inhibitory concentration (MIC) = 4 µM), which was around thirty times stronger than the parent peptide (MIC = 128 µM). Furthermore, crabrolin-TR showed an in vivo treatment efficacy in a Klebsiella-pneumoniae-infected waxworm model and was non-toxic under its maximum MBC value (MIC = 8 µM), indicating its therapeutic potency and better selectivity. Overall, we rationally designed functional peptides by progressively increasing the number and distribution of charged residues, demonstrating new insights for developing therapeutic molecules from natural resources with enhanced properties, and proposed crabrolin-TR as an appealing antibacterial and anticancer agent candidate for development.

Gut bacterial diversity in Vespa velutina and implications for potential adaptation in South Korea.

BACKGROUND: Invasive species such as the yellow-legged hornet (Vespa velutina), along with four other Vespa species - Vespa analis, Vespa crabro, Vespa ducalis, and Vespa mandarinia - pose significant threats to the environment, economy, and human health. This study focuses on understanding the key factors contributing to the successful invasion of these species, particularly V. velutina, in South Korea. The analysis encompasses the gut bacterial communities and stable isotopes of carbon and nitrogen of the queen hornets, aiming to identify variances in gut microbial composition and food resource utilization. RESULTS: The gut bacterial communities in the five Vespa species were primarily composed of Proteobacteria, with Firmicutes and Bacteroidetes present. Vespa velutina and V. mandarinia had higher Firmicutes abundance at the phylum level, possibly indicating an increased capacity for dietary fiber breakdown and short-chain fatty acid production, providing them with a competitive edge. No significant differences in nitrogen and carbon stable isotope values were found among the five Vespa species, suggesting that they fed on similar food sources. However, V. velutina had a higher number of unique gut bacterial operational taxonomic units (OTUs), implying adaptation through the acquisition of a distinct gut bacterial set. Significant correlations were found between the observed index and the Shannon index, and between δ15 N and the observed index, suggesting that the food source diversity may influence the gut bacterial community diversity. CONCLUSION: Our study offered valuable insights regarding the adaptation of V. velutina to its new environment in South Korea. The potential role of gut microbiota in the success of invasive species was elucidated. This information is crucial for the management of invasive species, targeted control methods, and implementing preventive regulations. Further studies with larger sample sizes and comprehensive sampling are required to gain a complete understanding of the gut microbiota of Vespa species and their adaptation to new environments. © 2023 Society of Chemical Industry.

Detection of honey bee viruses in larvae of Vespa orientalis.

The Oriental hornet (Vespa orientalis) is one of the major predators of honey bees. It has been demonstrated that adults of V. orientalis can harbor honey bee viruses, however the transmission route of infection is still not clear. The aim of this study was to study the possible presence of honey bee viruses in V. orientalis larvae and honey bees collected from the same apiary. Therefore, 29 samples of V. orientalis larvae and 2 pools of honey bee (Apis mellifera). samples were analyzed by multiplex PCR to detect the presence of six honeybee viruses: Acute Bee Paralysis Virus (ABPV), Black Queen Cell Virus (BQCV), Chronic Bee Paralysis Virus (CBPV), Deformed Wing Virus (DWV), Kashmir Bee Virus (KBV) and Sac Brood Virus (SBV). Biomolecular analysis of V. orientalis larvae revealed that DWV was present in 24/29 samples, SBV in 10/29, BQCV in 7/29 samples and ABPV in 5/29 samples, while no sample was found positive for CBPV or KBV. From biomolecular analysis of honey bee samples DWV was the most detected virus, followed by SBV, BQCV, ABPV. No honey bee sample was found positive for CBPV or KBV. Considering the overlapping of positivities between V.orientalis larvae and honey bee samples, and that V.orientalis larvae are fed insect proteins, preferably honey bees, we can suggest the acquisition of viral particles through the ingestion of infected bees. However, future studies are needed to confirm this hypothesis and rule out any other source of infection.