Italy which is by far the most heavily infested country in Europe imported the mosquito from India.

The EEA said on Thursday said that the mosquito is now present in Albania, Bosnia and Herzegovina, Croatia, France, including Corsica, Greece, Monaco, Montenegro, the Netherlands, Italy, including Sicily and Sardinia, Slovenia, Spain and Switzerland, plus — but needing further confirmation — Belgium and Germany.

EEA says that predictions under different climate change scenarios show that the species will likely expand its European range even further in the near future, particularly in the Mediterranean basin, but also as far north as the Baltic states and part of Scandinavia.

Since the flight range of adults is limited to a few hundred metres, any long distance dispersal needs to be mediated by human activity.

The EEA said, "Currently there is solid evidence for its role in the transmission of two diseases: dengue and chikungunya. The small outbreak of chikungunya virus that developed in north-eastern of Italy during the summer of 2007 has clearly shown that the tiger mosquito is an important disease vector and may represent a true public health challenge. The outbreak in Italy was made possible by immigration of a single infected (but asymptomatic) man from India and the enormous population of tiger mosquitoes in the peninsula."

Aside from its role as vector of diseases, the EEA says, the Asian tiger mosquito is also known as an aggressive diurnal biter — unlike most other mosquitoes which are crepuscular or nocturnal — and as such represents a serious nuisance, particularly in the summers when it reaches high densities.

EEA says that in addition to the health impact, the invasion of this mosquito has also had a major economic impact, particularly in relation to treatment costs. Further evidence of the mosquito's potential devastating impacts exists from other outbreaks of chikungunya virus on La Reunion island in 2005-2006, with more than 250000 infections and several deaths.