Vespa Velutina Research Articles

QuEChERS-Based Method for the Determination of Fipronil in Protein Baits and Vespa velutina Larvae by HPLC-DAD and GC-MS

Protein baits containing fipronil as a biocide have shown their effectivity as a control method for Vespa velutina nigrithorax (Lepeletier, 1836) in apiaries. This biocide is not selective for Vespa velutina, so it is important to use the minimum dose to inactivate a nest. Therefore, the aim of this work was the development of analytical methods for the determination of fipronil in protein baits for quality control purposes and in larvae of Vespa velutina to determine the biocide content after protein bait ingestion and to acquire knowledge on fipronil metabolism in larvae. For this purpose, a Quechers-based HPLC-PDA method was developed and validated for the determination of fipronil in both matrixes. Furthermore, a GC-MS method was developed for the analysis of fipronil and its metabolites in dead Vespa velutina larvae fed with a mash containing 0.01% fipronil. Quechers-based HPLC-DAD allowed for the determination of the fipronil content in baits. Fipronil and the metabolites fipronil sulfone and fipronil sulfide were identified by GC-MS in extracts of larvae fed with a protein mash containing 0.01% fipronil. The transformation of fipronil into fipronil sulfone inside the larvae and the high toxicity of this metabolite open the possibility to produce protein baits with lower biocide concentrations.

Microstructural properties of Asian hornet nest paper-like materials: Preliminary step towards biomimicry materials for civil engineering applications

This paper presents a comprehensive examination of the microstructure and mineralogy of the paper-like material found in Asian hornet nests (referred to as AHN P-LM) and the nearby tree leaves, utilising scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD). The analysis conducted through SEM-EDS demonstrates that AHN P-LM is primarily composed of plant fragments, with slight traces of inorganic substances (such as CaOx). The thread-like morphologies observed in the SEM analysis, which are linked to the secretion of hornets, warrant attention due to their significance in understanding the microstructure of AHN P-LM. The presence of nitrogen (N) in the EDS analysis of AHN P-LM, in contrast to its absence in analysed leaves, strongly implies that the nitrogen originates from hornet saliva. Additionally, SEM-EDS analysis revealed the impact of chemical composition variations on colour differences within AHN P-LM. Furthermore, X-ray diffraction analysis on ash samples from AHN P-LM confirmed the presence of minerals such as quartz, lime, phlogopite, and microcline. These findings about mineral composition align closely with results obtained from SEM-EDS analyses, presenting various aspects related to understanding the structure and compositional makeup of AHN P-LM. Biomimicry principles can be applied to draw inspiration from the AHN P-LM for replication in the civil engineering field, facilitating innovative solutions. Understanding hornet behaviour and nest material composition is essential. Future outlook includes utilising these materials in wood construction, 3D printing for structural components, shelters, infrastructure repair, green building, and architectural innovation.

Differentiation of Vespa velutina nigrithorax Colonies Using Volatile Organic Compound Profiles of Hornets and Nests.

Vespa velutina (Lepeletier, 1836) (Hymenoptera: Vespidae) is a eusocial insect that lives in colonies of hundreds to thousands of individuals, which are divided into castes according to their task: queens, workers, and males. The proper functioning of the colony requires communication between the individuals that make up the colony. Chemical signals (pheromones) are the most common means of communication used by these insects to alarm and differentiate between individuals belonging or not to the colony. In this work, profiles of volatile organic compounds were obtained from the hornets and the external cover of four secondary nests located in the Basque Country. The obtained profiles were treated using chemometric tools. The grouping of hornets and nests according to the different colonies and geographical location was observed. In total, 37 compounds were found in common in hornets and nests. Most of them have been reported in the literature as belonging to different insects and plant species. This would corroborate the transfer of chemical compounds between the nest and the hornets' nest and vice versa. This information could be applied to the development of more efficient control methods for this invasive species, such as attractive traps or baits containing the relevant compounds.

Phylogeographic Analysis for Understanding Origin, Speciation, and Biogeographic Expansion of Invasive Asian Hornet, Vespa velutina Lepeletier, 1836 (Hymenoptera, Vespidae)

The Asian hornet, Vespa velutina, is an invasive species that has not only expanded its range in Asia but has also invaded European countries, and it incurs significant costs on local apiculture. This phylogeographic study aims to trace the evolutionary trajectory of V. velutina and its close relatives; it aims to identify features that characterize an invasive species. The last successful invasion of Vespa velutina into France occurred in late May, 2002, and into South Korea in early October, 2002, which were estimated by fitting a logistic equation to the number of observations over time. The instantaneous rate of increase is 1.3667 for V. velutina in France and 0.2812 in South Korea, which are consistent with the interpretation of little competition in France and strong competition from local hornet species in South Korea. The invasive potential of two sister lineages can be compared by their distribution area when proper statistical adjustments are made to account for differences in sample size. V. velutina has a greater invasive potential than its sister lineage. The ancestor of V. velutina split into two lineages, one found in Indonesia/Malaysia and the other colonizing the Asian continent. The second lineage split into a sedentary clade inhabiting Pakistan and India and an invasive lineage colonizing much of Southeast Asia. This latter lineage gave rise to the subspecies V. v. nigrithorax, which invaded France, South Korea, and Japan. My software PGT version 1.5, which generates geophylogenies and computes geographic areas for individual taxa, is useful for understanding biogeography in general and invasive species in particular. I discussed the conceptual formulation of an index of invasiveness for a comparison between sister lineages.

Honey bee viruses in the yellow-legged hornet Vespa velutina (Lepelieter 1836): Prevalence, loads, and detection of replicative DWV and LSV forms

Apiaries in Galicia, northwestern Spain, are currently facing the invasive alien species Vespa velutina, which is well established in the region. The pressure on honey bee colonies is high, resulting in both economic and ecological losses. Honey bee colonies also face the challenge of viruses, which are becoming increasingly diverse. In recent years, honey bee viruses have been spreading across taxonomic groups beyond Apoidea, infecting the Vespoidea superfamily. This cross-species spillover has raised concerns in the scientific community due to the potential risk of viruses spreading in ecosystems. Currently, there is a lack of knowledge on this topic, and further research is needed to address this issue. This study employed qPCR and sequencing to investigate the prevalence, loads, and presence of replicative forms of important honey bee viruses in V. velutina individuals collected from 11 apiaries in Galicia. All V. velutina individuals tested positive for DWV, BQCV, AKI complex (ABPV, KBV, and IAPV), or LSV but not for CBPV. DWV showed the highest prevalence (97.0 %) and loads, with both DWV-A (67.4 %) and DWV-B (32.6 %) being detected. The AKI complex (46.3 %) and LSV (43.3 %) were also common, whereas BQCV (11.9 %) was rarer. LSV is detected for the first time in V. velutina. LSV-2 was the dominant strain (82.1 %), and two less frequent (17.9 %) unknown strains were also detected. All 44 screened V. velutina samples carried the replicative form of DWV, and six of these also carried the replicative form of LSV, raising for the first time the possibility of co-infection in the hornet. The detection of honey bee viruses in V. velutina, and the ability of these viruses to spread to other species, may indicate a potential risk of spillover in the apiaries.

Identification of alarm pheromone components of the southern giant Asian hornet, Vespa soror, a major pest of honey bees.

The rise of biological invasions threatens biodiversity and food security, with the vespid family, including Vespa soror, being of particular concern. Our study focused on the alarm pheromone components of V. soror. By using gas chromatography-mass spectrometry (GC-MS) chemical analyses, electroantennograms, and field bioassays, we identified 5 compounds-2-pentanol, 3-methyl-1-butanol, 2-heptanol, 2-nonanol (2-N), and isopentyl acetate (IPA)-in hornet sting venom that elicited defensive behavior from hornets. IPA and 2-N also serve as alarm pheromone components in multiple honey bee species that are important prey for V. soror. This shared chemical signaling may allow cross-detection by each species on the other's alarm cues. While it should be advantageous for bees to detect V. soror alarm pheromone, the benefits to V. soror of using IPA and 2-N are unclear. V. soror may manipulate bee behavior, potentially distracting defenders, because they mark victim bee colonies by rubbing their abdomens, which contain their sting glands, at bee hive entrances. Our findings pose new evolutionary questions about the role of manipulation in the arms races.

Prevalence and population genetic analyses of parasites in invasive Vespa velutina and native Hymenoptera

Invasive species pose a threat to the ecological balance of the ecosystems they invade by altering local host-pathogen dynamics. To investigate these relationships and their potential consequences, we examined the prevalence and genetic diversity patterns of Trypanosomatidae, Lipotrophidae, and Nosematidae in a collection of sympatric isolates of the invasive hornet Vespa velutina and local Hymenoptera from two recently colonized areas: Europe and South Korea. Data were gathered through PCR amplification and massive parallel sequencing, and analyses were conducted using population genetics tools. Parasite prevalences showed substantial variation depending on (i) the parasite family (Trypanosomatidae and Nosematidae were the most and less prevalent, respectively), (ii) location (e.g. Galicia displayed the highest pooled values), (iii) the season (highest in spring for Trypanosomatidae and Lipotrophidae), and (iv) the host. V. velutina exhibited significantly lower parasite occurrence than native Hymenoptera across all parasite families (consistent with the enemy release hypothesis), although this difference was less pronounced during the periods of heightened predatory activity, suggestive of trophic transmission. Parasite species displayed significant genetic differentiation between European and South Korean isolates, yet no differentiation was observed across hosts, suggesting that all Hymenoptera are exposed to a common local pathogen population. There was no indication that V. velutina acted as a carrier of foreign parasites to the invaded territories.

Volatile organic compound profile for the search of rejection markers in protein baits used as Vespa velutina control method

The invasive species Vespa velutina nigrithorax (Lepeletier 1836), commonly known as the Asian hornet, constitutes an economic and environmental threat, as it is a predator of fruits and insects, especially Apis mellifera (Linnaeus, 1758) (honey bees).Different methods have been developed for its control. Among of them, biocidal protein baits are included, which have a limited time of use. Oxidation of their components, enzymatic activity and microorganisms lead to the formation of spoilage compounds.The aim of this work was to determine the optimal conditions for storing and preserving the baits without losing efficacy. Furthermore, a search of rejection markers will be carried out based on field studies results in the apiary on the acceptance and rejection of the baits by hornets under different storage conditions.Volatile organic compound profiles of these baits were obtained by solid phase microextraction/gas chromatography/mass spectrometry (SPME-GC–MS). The data were processed using different statistical and chemometric tools.The identification of potential rejection markers belonging to the families of ketones, esters, alcohols and amines was carried out by partial least squares discriminant analysis (PLS-DA). The four markers with the highest VIP scores were 2-butanone, 2-heptanone, 1-butanol, 3-methyl and 1-butanol, 3-methyl, acetate.

Comparing the nest chemical profile of Vespa velutina and Vespa crabro: a potential tool to detect invasive hornet species

Comparing the nest chemical profile of Vespa velutina and Vespa crabro: a potential tool to detect invasive hornet species

Preparative Synthesis of 4-Oxooctanoic and 4-Oxodecanoic Acids - Components of Sex Pheromone of Asian Hornet Vespa velutina

Preparative Synthesis of 4-Oxooctanoic and 4-Oxodecanoic Acids - Components of Sex Pheromone of Asian Hornet Vespa velutina

Ecological integration of Vespa velutina Lepeletier, 1836 in South Korea: a comprehensive study of co-occurrence and interaction patterns with native social wasps.

The spread of Vespa velutina Lepeletier, 1836 (Asian hornet) in South Korea poses a threat to biodiversity and agriculture. Traditional species interaction models often fail to capture the complexity of invasive species dynamics. This study used association rule learning (ARL) and clustering analyses to explore the interactions of V. velutina with native Vespidae species in South Korea, with the aim of uncovering patterns of coexistence and competition. Over 4 years (2020-2023), 304 traps were strategically placed across South Korea to collect data on Vespidae species. Our findings showed that Vespula flaviceps, Vespa crabro, and Vespula koreensis were the most frequently encountered species. V. velutina was also widespread, suggesting its successful integration into local ecosystems. The ARL analysis, using the 'apriori' algorithm, identified significant co-occurrence patterns and potential interactions. The rules generated indicated both competitive and coexistent relationships with varying levels of association strength across different regions. Clustering analyses, including hierarchical and k-means clustering, grouped species based on their occurrence similarities. The distinct clusters formed in the analysis highlighted the unique ecological roles and interactions of V. velutina and other Vespidae species in South Korean ecosystems. This study confirms the successful establishment of V. velutina in diverse South Korean ecosystems and highlights its complex interactions with native species. These findings support the need for nuanced management strategies that consider the intricate ecological relationships of V. velutina. This approach is crucial for the effective management of invasive species and ecosystem conservation. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Twenty years of attempting to control the Vespa velutina invasion: will we win the battle?

Twenty years of attempting to control the Vespa velutina invasion: will we win the battle?

Pathogen occurrence in different developmental stages of the invasive Vespa velutina nigrithorax (Buysson, 1905).

The yellow-legged hornet (Vespa velutina nigrithorax) is a predatory species native to South-East Asia. The hornet is invasive in Europe, spreading to several countries and becoming a pest for Apis mellifera due to its behaviour of preying in front of apiaries. The aim of this study was (i) to investigate the presence of honey bee pathogens within the developmental stages of V. velutina after neutralizing a nest in Bologna province (Emilia-Romagna, Italy) and (ii) to analyze the mitochondrial DNA to determine if the population derived from the population initially introduced in Europe. The results indicated that deformed wing virus (82.76%) and Nosema ceranae (67.28%) were the most prevalent pathogens. Deformed wing virus, N. ceranae and sacbrood virus were found in all investigated stages, while chronic bee paralysis virus and Kashmir bee virus were exclusively found in foraging adults. All detected viruses were found to be replicative, highlighting active infection in the hosts. The mtDNA analysis demonstrated that the origin derived from the invasive population arrived in France. This study underscores the importance of further research to understand the effect of interspecific transmission, especially concerning the potential role of these pathogens as a biocontrol for the invasive V. velutina nigrithorax. © 2024 Society of Chemical Industry.

Future Range Expansions of Invasive Wasps Suggest Their Increasing Impacts on Global Apiculture.

Until now, no study has examined the future range dynamics of major invasive wasp species to assess their future impacts on global apiculture. Here, we developed 12 species distribution models to calibrate the future range dynamics of 12 major invasive Vespidae wasp species under a unified framework. An increase in their habitat suitability was identified in more than 75% of global land. Substantial range expansions were detected for all 12 species, and they were primarily induced by future climate changes. Notably, Polistes dominula and Vespa crabro had the largest potential ranges under all scenarios, suggesting their greater impact on global apiculture. Polistes chinensis and Vespa velutina nigrithorax had the highest range expansion ratios, so they warrant more urgent attention than the other species. Polistes versicolor and P. chinensis are expected to exhibit the largest centroid shifts, suggesting that substantial shifts in prioritizing regions against their invasions should be made. Europe and the eastern part of the USA were future invasion hotspots for all major invasive wasp species, suggesting that apiculture might face more pronounced threats in these regions than in others. In conclusion, given their substantial range shifts, invasive wasps will likely have increasingly negative impacts on global apiculture in the future.

Niche modelling and landscape genetics of the yellow-legged hornet (Vespa velutina): An integrative approach for evaluating central-marginal population dynamics in Europe.

Genetic diversity is an important biological trait for a successful invasion. During the expansion across a new territory, an invasive species may face unprecedented ecological conditions that will determine its demography and genetic diversity. The first record of the yellow-legged hornet (Vespa velutina) in Europe dates back to 2004 in France, from where it has successfully spread through a large territory in the continent, including Italy, Spain and Portugal. Integrative approaches offer a powerful strategy to detect and understand patterns of genetic variation in central and marginal populations. Here, we have analysed the relationship between genetic diversity parameters inferred from 15 V. velutina nuclear DNA microsatellite loci, and geographical and environmental drivers, such as the distance to the introduction focus, environmental suitability and distance to native and invasive niche centroids. Our results revealed a central-marginal dynamic, where allelic richness decreased towards the edge of the expansion range. The low environmental suitability of the territories invaded by marginal populations could prevent a diverse population from establishing and reducing the genetic diversity in populations at the expansion edge. Moreover, Markov chain Monte Carlo analysis showed both geographical and environmental distances were influencing population genetic differentiation. This study highlights the importance of combining genetic analysis with geographical and environmental drivers to understand genetic trends of invasive species to new environment.

G-space versus E-space: Are hornets (Hymenoptera: Vespidae) at equilibrium with honeybees in Asia?

This study delves into the concept of niche conservatism (NC) and its implications for how hornets (Hymenoptera: Vespidae) and honeybees respond to climate change. Our primary objectives are threefold: firstly, to assess whether distinct environmental niche spaces (E-space) exist between 12 hornets and honeybees like Apis cerana and Apis mellifera in Asia; Secondly, to explore the degree to which Asian hornets have attained geographic equilibrium alongside honeybee species. Lastly, is to investigate how the geographic niche overlap (G-space) between hornets and honeybees could potentially change under climate change scenarios. To accomplish these goals, we employed ordination and ecological niche modeling techniques to analyze 91 pairs of hornets and honeybees in both geographic (G-space) and environmental (E-space) contexts. Then, we projected the potential impacts of climate change on the future geographic overlap between hornets and honeybees, specifically under the SSP585 climate scenario for the year 2070. Our results demonstrated that the environmental niches (E-space) of hornets and honeybees can be treated as interchangeable, indicating they have similar environmental preferences despite being unrelated taxa. We found that Vespa velutina currently exhibits a moderate geographic niche overlap (G-space) of 0.63 with both honeybee species. Meanwhile, Vespa mandarinia demonstrates an overlap of 0.46 with Apis cerana and 0.63 with Apis mellifera. The overlap of Vespa velutina with Apis cerana might potentially decrease to 0.51 and 0.56 with Apis mellifera. For Vespa mandarinia, the overlap could reach 0.41 with Apis cerana and 0.6 with Apis mellifera under a climate change scenario. This study indicates that the limited spatial overlap between honeybees and hornets across certain areas in Asia is more likely influenced by geographical barriers rather than solely environmental unsuitability for hornets. In this study, we delve into the concept of niche conservatism (NC) and its implications for how hornets (Hymenoptera: Vespidae) and honeybees respond to climate change.

Identifying Morphs of the Yellow-Legged Hornet (Vespa velutina) and Other Pests of Quarantine Importance with Geometric Morphometrics

We assess the accuracy of geometric morphometrics (GMM) for determining the origin of insects of quarantine importance using the Asian hornet (Vespa velutina Lep.1836) as a case study. This species is highly variable, has an extensive natural distribution, and has been transported to many regions of the world. Forewing landmarks were applied to a large sample of regionally specific color morphs (previously considered “subspecies”) from across the species’ native Asian range. We reconfirm that GMM can statistically distinguish geographic variants independent of the color patterns that have heretofore been used for provenance, but which have been suspected of being unreliable. Almost all morphs in our analyses were statistically different except the centrally located V. v. variana, whose range lies between the continental V. v. auraria Smith, 1852, and V. v. nigrithorax du Buysson, 1905 morphs, and the Malaysian and Indonesian morphs. Even with moderate-sized training samples, discriminant function analysis (DFA) was able to classify geographic morphos with about 90% accuracy (ranging from 60% to 100%). We apply these results to determine the origin of a dead wasp recently intercepted in a mail parcel in Utah. Both DFA and continuous-trait maximum-likelihood clustering suggest that the Utah specimen belongs to the nigrithorax morph, which is native to southern China but now invasive in Europe, Japan, and Korea. These results are also supported by DNA barcode analysis, which groups the Utah individual with nigrithorax populations in South Korea and Japan. The relationship between variation in wing shape and genetic differentiation deserves further study, but molecular data are consistent with the GMM results suggesting that morphometric comparisons may be able to identify and provenance intercepted specimens quickly and inexpensively when molecular sequences and taxonomic specialists are unavailable.

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

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.

Activity of the Reproductive Generation and Nest Temperature Regulation by the Invaded Hornet, Vespa velutina nigrithorax in Autumn Season

Activity of the Reproductive Generation and Nest Temperature Regulation by the Invaded Hornet, Vespa velutina nigrithorax in Autumn Season

VespAI: a deep learning-based system for the detection of invasive hornets

The invasive hornet Vespa velutina nigrithorax is a rapidly proliferating threat to pollinators in Europe and East Asia. To effectively limit its spread, colonies must be detected and destroyed early in the invasion curve, however the current reliance upon visual alerts by the public yields low accuracy. Advances in deep learning offer a potential solution to this, but the application of such technology remains challenging. Here we present VespAI, an automated system for the rapid detection of V. velutina. We leverage a hardware-assisted AI approach, combining a standardised monitoring station with deep YOLOv5s architecture and a ResNet backbone, trained on a bespoke end-to-end pipeline. This enables the system to detect hornets in real-time—achieving a mean precision-recall score of ≥0.99—and send associated image alerts via a compact remote processor. We demonstrate the successful operation of a prototype system in the field, and confirm its suitability for large-scale deployment in future use cases. As such, VespAI has the potential to transform the way that invasive hornets are managed, providing a robust early warning system to prevent ingressions into new regions.