Biodiversity Foundation Project: STOP Vespa velutina
- Type Project
- Execution 2021
- Scope Europeo
- Main source of financing Fundación Biodiversidad
- Project website Web proyecto (Fundación Biodiversidad)
From a scientific perspective and based on a study of genetic diversity, the project has worked to evaluate the entry and spread routes of the Asian hornet in the Iberian Peninsula and the Balearic Islands in order to establish specific management measures for the species.
It has been determined that the species' presence in the Balearic Islands is due to two independent introductions: the first in 2015 from Italy and the second in 2021 from the Iberian Peninsula, mainly from Catalonia.
The results also suggest that the most likely scenario for the Asian hornet's invasion in Europe could have arisen from the expansion of the population initially established in France into Spain and Italy.
- Compilation of Vespa velutina individuals collected in the Balearic Islands between 2015 and 2018, yielding a total of 274 adults. Compilation of 61 adult individuals collected from different locations across the Iberian Peninsula (specifically Catalonia, the Basque Country, Asturias, Galicia, and Extremadura) and shipment to the Zoology and Genetics laboratories of the University of the Balearic Islands. Compilation of the 335 samples collected in total and storage for processing and molecular analysis. Extraction and purification of genomic DNA from the three right legs of the 335 individuals.
- Quantification of DNA present in extractions by fluorimetry and analysis of DNA integrity by electrophoresis. Amplification of regions corresponding to the cytochrome oxidase I (cox1), cytochrome b (cytB) and 16S ribosomal subunit genes. Bidirectional sequencing of PCR products relating to the cox1 gene using the Sanger technique. Setup and amplification by multiplex PCR of a total of 22 STR repeat loci with demonstrated resolution capacity in the Asian hornet.
- Analysis of amplified STR fragments on the ABI Prism 3130 DNA genetic analyzer.
- Analysis of the electropherograms obtained and generation of contigs using CodonCode Aligner. Genotyping of the hornets for the 22 loci studied was performed using GeneMapper software. Bioinformatics analysis of the DNA sequences was used to generate phylogenetic trees and haplotype networks.
- Genotypic diversity analysis, comparing the microsatellite data generated throughout the project for the 335 individuals with an existing dataset containing genotypes from 417 individuals collected in invaded regions of Spain and in the native distribution areas of Vespa velutina in Southeast Asia. From these data, various results were obtained regarding estimated population parameters, such as allele frequencies, observed number of alleles, allele richness, genetic structure of Asian hornet populations, etc.
- Implementation of the approximate Bayesian estimation method to estimate the genetic origin of invasions and the number of independent colonization events.
- Detailed analysis of the genetic profiles of Balearic samples from all nests located and queens trapped since 2015 to establish the patterns of gene flow and dispersal of the species during this time period.
- Preparation of a final project report explaining and detailing all the work carried out during the project and proposing management measures for the invasive species.
- Project dissemination and communication: participation in a regional conference and three international conferences where the project results were presented; four meetings with researchers, managers, and interested members of the public, where the results were also presented; publications on social media; preparation of a scientific article; drafting a final report on the project's results; etc.
The Asian hornet (Vespa velutina) is a species included in the Spanish Catalogue of Invasive Alien Species according to Royal Decree 630/2013, for which there is a management, control, and possible eradication strategy. It was first detected in France in 2004 and quickly spread to nearby countries such as Spain. This wasp preys on insects, primarily bees. The University of the Balearic Islands highlights that its introduction causes significant impacts on biodiversity, affecting pollination in natural ecosystems and leading to the decline of wild insects. It also creates economic problems (mainly for beekeeping and crop pollination) and health problems (due to potential stings).
The route of introduction into Europe from Asia is unclear, nor is its arrival in Portugal, Galicia, or the Balearic Islands. According to the organization, to prevent the introduction of this invasive species, it is essential to know how and from where it arrived in each region. This project has conducted a study of its genetic diversity to understand the routes of entry and spread, and to propose specific management measures.
The overall objective of the project was to evaluate the entry and dispersal pathways of the Asian hornet in the Iberian Peninsula and the Balearic Islands in order to establish specific management mechanisms for the species. The specific objectives were as follows: Collect samples of Asian hornets from the Iberian Peninsula and the Balearic Islands. Extract DNA from the samples. Quality control of DNA extractions. PCR amplification of three key regions of the mitochondrial genome. Sequencing of mitochondrial molecular markers. Amplification of 22 microsatellite regions of the nuclear genome (STR). Sequencing of STR fragments. Bioinformatic editing of DNA sequences. Analysis of STR data. Genetic characterization of individuals from the Iberian Peninsula and the Balearic Islands. Uncover the origin of individuals from the Iberian Peninsula and the Balearic Islands and the number of colonization events. Evaluate the gene flow of the species in the Balearic Islands. Prepare a document with the information obtained so that it can be included in the Asian hornet management, control, and possible eradication strategy. Disseminate and communicate the project's results and conclusions.
The STOP Vespa velutina project aimed to assess the entry and spread routes of this species in the Iberian Peninsula and the Balearic Islands, in order to establish specific management mechanisms.
This is an extensive project involving significant laboratory genomic research. At the start of the project, samples were collected from individuals previously collected in the Balearic Islands in previous years and prepared for subsequent analysis. A total of 274 adult Vespa velutina specimens were collected from the invasion of Mallorca, and 61 from the Iberian Peninsula, resulting in a total of 335 samples.
Mitochondrial and nuclear DNA analysis has revealed two independent introductions to the Balearic Islands: the first in 2015 from Italy and the second in 2021 from the Iberian Peninsula, primarily from Catalonia. Furthermore, mitochondrial and nuclear analyses suggest that Vespa velutina populations in both mainland Spain and the Balearic archipelago may have been derived from the southward expansion of the species' population initially established in France.
The results also indicated that the most likely scenario for the Asian hornet's invasion in Europe, both in mainland Spain and the Balearic Islands, could have resulted from the southward expansion of the population initially established in France (towards Spain and Italy), rather than multiple independent introductions from its native range. According to the organization, once it entered Spain through the western Pyrenees, the invasive populations dispersed throughout the northern Iberian Peninsula, reaching the autonomous communities of Catalonia and Galicia, and eventually reaching Portugal. Furthermore, it is concluded that the Mediterranean islands could not be colonized naturally, and that it could only reach the Mediterranean islands through accidental human introduction.
The laboratory work has been complemented by the dissemination of information on the species' problems through various regional and national media outlets, targeting diverse audiences, from the scientific community to society at large. Finally, a final project report has been prepared, explaining and detailing all the work carried out during the project and proposing measures to add to the strategy for managing, controlling, and potentially eradicating the species.
- Universidad de las Islas Baleares
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