Colonisation patterns of Catalonia (northeast Spain) by the tiger mosquito (Aedes albopictus): trends from 2004 to 2008
Antoni Torrell, Jordi Ruiz, Mariano Rojo: Flora, Fauna and Pet Protection Service, Government of Catalonia, Barcelona, Spain.
Roger Eritja: Mosquito Control Service, Regional Council of El Baix Llobregat, Spain.
Eduard Marquès: Mosquito Control Service of Roses Bay and the Lower Ter, Castelló d’Empúries, Spain.
Presented by: Patricia Valle Trujillo: Public Health Manager – Kenogard Spain.
Aedes albopictus was initially detected in Spain in 2004 (Aranda et al.) in the municipality of St. Cugat del Vallès (Barcelona province). In the last 5 years, the tiger mosquito population has spread, and stable populations of this mosquito being currently to be found in 85 municipalities in Catalonia, potentially affecting over 4 million people.
2005 saw the establishment of a Working Group that comprises the Departments of Health and of the Environment of the Government of Catalonia, Barcelona Provincial Council, the Barcelona Public Health Agency, the Regional Councils of El Baix Llobregat (including the group Mosquito Control Service) and El Vallès Occidental and different municipalities where presence was potential.
To fight the tiger mosquito, this Working Party established the following priorities:
- Communication of the problem, since some preventive control measures on a private level stem from notification.
- Coordination of control work on a municipal scale.
- Monitoring to determine dispersion and the colonisation of new sites by Aedes albopictus.
- Advising population.
In 2005, ovitraps were used to characterise the tiger mosquito population in Catalonia and to accurately determine the municipalities affected and with what intensity.
The 2006 study left no doubt that the tiger mosquito was clearly expanding throughout Catalonia. Not only was it spreading like an oil stain; it was also travelling large distances, which was demonstrated by its presence in municipalities located several kilometres from the initial concentration.
In 2007, monitoring of the species continued to determine its evolution and its rate of expansion, bearing in mind the likelihood that the mosquito would continue to colonise new territories close to those already affected. Nonetheless, the possible appearance of concentrations that were isolated and distant from the risk
area also had to be considered.
The 2008 study has shown that the colonisation of new territories by this mosquito has not stopped, mainly because of: climate, the large number of available breeding sites, and the great mobility of vehicles in Catalonia.
A predictive model is being developed to asses the final scenario for the presence of the species.