Mosquito monitoring at Vienna-Schwechat Airport

In recent decades, alien mosquito species have become more prevalent in Europe. Mosquitoes are passively introduced into new areas, mainly through the global transport of goods. If suitable climatic conditions prevail there, new populations can become established in these areas. These introduced mosquito species pose a potential threat, as they can also carry exotic pathogens.

Of particular concern in this regard is the Asian tiger mosquito(Aedes albopictus). This species is a potential vector for over 20 different pathogens such as Chikungunya virus, Dengue virus, Dirofilaria. The tiger mosquito is also highly adaptable and has increasingly spread throughout Europe: Established populations already exist in Italy, Switzerland and Slovenia. We have also detected the tiger mosquito in Austria: In 2012 in Tyrol and Burgenland, in 2016 and 2017 in Tyrol. It is currently still unclear whether the Asian tiger mosquito has been repeatedly introduced here, or whether stable populations have already established in these areas. In 2020, we detected this species for the first time in Vienna and in 2021 for the first time in Graz.

Method

We have set up 23 mosquito traps at Schwechat Airport (including cargo and passenger areas along the airfield, Cargo Center).

To catch adult mosquitoes, we use two traps that attract the mosquitoes by means of carbon dioxide (CO2) and a scent.

21 so-called ovitraps ("egg-laying traps") represent artificial breeding sites and are designed to encourage females of container-breeding species of the genus Aedes to lay their eggs in these very traps.

Adult mosquitoes and eggs were identified by morphological characteristics and genetic species identification was performed by whole genome sequencing, respectively.

Results

In 2021, we detected eggs of the Asian tiger mosquito(Aedes albopictus) for the first time at Vienna-Schwechat Airport. We detected two egg clutches, with seven weeks between these findings: this period is well above the mean life expectancy of female Asian tiger mosquitoes, which is two to three weeks. Presumably, tiger mosquitoes were able to breed here (for a short time); however, a second entry event cannot be ruled out. The location of the find suggests an introduction via air traffic.

Through this monitoring project, the occurrence of these alien species at the airport was detected at an early stage. As a result, countermeasures can be taken in good time. The data are also used to record spatial and temporal changes in the occurrence of alien mosquito species throughout Austria.

Mosquito monitoring at Vienna International Airport is carried out in cooperation with the University of Veterinary Medicine Vienna.

Mosquito monitoring at Vienna International Airport: Annual report 2021