Near Amsterdam, a small colony of Aedes aegyptii mosquitoes, known as yellow fever mosquitoes, was found near a plant owned by a company that imported used US tires. Scientists agree that this population has little chance of survival, but not only this species of disease-transmitting mosquito is trying to colonize Europe, writes Science magazine.
According to Science, the mosquitoes were found by a team led by Ernst Jann Scholte of the Netherlands Government Vector Monitoring Center. According to scientists, they do not currently pose a direct health threat and are unlikely to survive the winter. Nevertheless, researchers are surprised because these insects were last seen in Europe more than 50 years ago. The species inhabited southern Europe in the XNUMXth and XNUMXth centuries, but probably disappeared after World War II after the indiscriminate use of DDT.
A. aegyptii is native to Africa, but has colonized tropical and subtropical areas around the world. It is a carrier of the Dengue virus, which is infected with fever, severe joint pain and hemorrhagic fever syndrome (Dengue fever).
Although the Dutch climate is not favorable for this species, the likely translocation to the south of Europe could cause it to be recolonized by these mosquitoes, said Science Francis Schaffner, French mosquito control expert at the University of Zurich in Switzerland. His team also found Aedes aegyptii during a routine surveillance program to observe another mosquito, Aedes albopictus, which transmits both Deng and Chikungunya fever. This species of mosquito has been rapidly occupying new territories over the last 20 years, especially in Mediterranean countries, from where it begins to penetrate to the North, e.g. through the transported secondary raw materials for disposal. It is especially often found in shipments of used tires shipped in containers around the world. The species was also found in Dutch greenhouses where bamboos imported from Asia were found, Science reports.
Until now, however, it was not realized that A.aegytpii was also a frequent stowaway in recyclable containers, and when Scholt’s team first caught an intruder in one of their traps, they mistook him for A. albopictus. Only the genetic test allowed for the correct identification. The team believes that the most likely origin for both species is the tire shipment from Miami, USA in May, where both species are common.
They are not – as Science reports – the only species of mosquitoes that can establish themselves in Europe. Already in the summer of 2009, Scholt’s team found a third, also alien, mosquito species – Aedes atropalpus – near the tire importer’s headquarters. This species inhabits the northern USA and south-eastern Canada and could easily install in northern Europe. Fortunately, it is not an important vector of disease.
The Dutch government, which abolished mosquito control programs decades ago, has now hired Schaffner and a second French expert on mosquito biology to help get rid of alien species trying to colonize the United Provinces. The researchers plan to use two agents: deltamethrin to exterminate adults and biological control agents to kill larvae. Schaffner believes that it is possible to nip any invasion of the Netherlands by all three species of mosquitoes in the bud.
But countries that are less stringent in controlling new invasions may be less fortunate, Science Scholte said. Researchers believe that colonization with new species of mosquitoes may occur especially after the heavy floods that have hit Europe for two years. (PAP)