The citizen scientists participating in the ‘Invasion of the Eastern Hornet in Andalusia’ project have defined a map with the expansion zones of this invasive species, which has increased by up to 30% between 2023 and 2024, with the provinces of Cádiz, Málaga, and Seville being the most affected. This study confirms the objective of tracking the distribution of this species (‘Vespa orientalis’) and predicting its impact on ecosystems and the local economy.
The results of the initiative, led by the citizen scientists of the Environmental Education Association ‘El Bosque Animado’ (Málaga), demonstrate that the 30% increase experienced by this invasive species between 2023 and 2024 implies a growing risk to native biodiversity, as well as to sensitive economic sectors such as agriculture and apiculture, due to predation on honey bees and even other local wasps. «It also poses a risk to coexistence with humans, and its presence as a pest can affect specific crops such as grapes. However, it cannot be combated with pesticides because this method could affect local biodiversity; the only method to mitigate it is nest removal,» explains Florent Prunier, biologist at ‘El Bosque Animado’ and scientific advisor to the project.
The project started with the scientific objectives of detecting the species, monitoring its colonized areas, updating distribution maps, identifying the species they prey on, facilitating the prediction of their area of influence, and assessing the utility of applications for monitoring invasive species in citizen science.
Citizen participation
To create the map, citizen scientists used the Observation.org platform during the summer and fall of 2024. Through a mobile application, they documented and recorded the presence of the Eastern Hornet, which was initially concentrated in Cádiz and Málaga, but then observed in all Andalusian provinces.
The study is supported by the Citizen Science Office of Andalusia, coordinated by the Descubre Foundation – Ministry of University, Research, and Innovation and Pablo de Olavide University, aiming to promote the use of this methodology among different stakeholders in the region. Specifically, it involves the active involvement of a community to address a local problem with knowledge-based actions.
As explained by project coordinator Florent Prunier, the Eastern Hornet comes from regions in South Asia, the Middle East, and North Africa, and has spread to Europe, adapting to the Mediterranean climate. «The rapid spread of ‘Vespa orientalis’ emphasizes the need to establish early warning systems, control protocols, and citizen awareness campaigns to mitigate its impact on the environment and the Andalusian economy,» he adds.
Members of the Environmental Education Association ‘El Bosque Animado’.
This expert coordinates the project in collaboration with researcher Diego Gil-Tapetado, postdoctoral researcher at the University of Murcia, platform coordinator Observation.org in Spain, Julio Rabdán, and predoctoral researcher at the Doñana Biological Station Jairo Robla.
A varied diet
Regarding its varied diet, the research team specifies that the Eastern Hornet consumes animal remains such as birds, often sparrows and pigeons, small mammals like rats, reptiles like lizards and snakes, freshwater and marine fish, and invertebrates, including large grasshoppers, beetles, aphids (or their honeydew), and even sea urchins, jellyfish, and shrimp.
Its diet is not limited to animals. The Eastern Hornet also feeds on feces and human food remains, tree sap like tamarisk and vineyards, where it feeds on ripe grapes, as well as ivy fruits. It also consumes late-season flowering plant species such as fennel, sage, olivarda, and viper’s bugloss, as well as exotic ornamental plants native to its native area, such as shrubs from the myrtle family or agave.
Exponential growth
The citizen scientists have documented and recorded the presence of the Eastern Hornet through a mobile application, with the option to attach photographs to validate observations. With this resource, which includes geolocation, participants have placed this species on an interactive map that facilitates the visualization and understanding of the data collected.
The expert team started from a data history collected since 2018, whose map reveals that the presence of the hornet was concentrated in the province of Cádiz and has been growing exponentially year after year. To disseminate the study results, the project coordinators have organized a series of outreach events such as ‘Cafés with Science’ and an informative workshop, and have participated in events in the Ronda mountain range, such as the Montejaque ornithological fair and the agro-artistic market of Genalguacil.
Citizen science to study biodiversity
The project is co-financed by the Ministry of University, Research, and Innovation, responsible for research and innovation policies in Andalusia, the Spanish Foundation for Science and Technology, the Ibercivis Foundation – pioneers of the Citizen Science Observatory in Spain, the Andalusian Academies Institute, the Ministry of Educational Development and Professional Training, the Andalusian Society for Science Communication, and ONCE Andalusia.
