Giant ticks, mosquitoes – alarm: climate crisis brings us tropical diseases

Warm winter, hot spring and dry summer: climate change is slowly catching up with us and the consequences are already being felt. Where mosquitoes used to only shake hands on warm summer evenings, mosquitoes now buzz around in the air during the day. A worrying trend can also be observed in the field of ticks: the giant tick is on the rise.

Two giant ticks have already been found in Austria this year
First spotted in Austria in 2018, conditions at home used to be too cold and too dry. Today, the giant ticks carried by migratory birds feel comfortable enough to spend the winter in Austria and go hunting in the spring – according to “Falter”, two giant ticks were already found in 2023 in Vorarlberg and Lower Austria.

Up to six millimeters long
The giant tick, also called Hyalomma marginatum, can grow up to six millimeters in length – significantly larger than the common wood tick or the relict tick. And the hunting instinct of the giant tick also gives you goosebumps: the crawling arachnid chases its “prey” up to 100 meters away at a brisk pace. Anyone bitten by a hyalomma should be careful, as it is considered a carrier of Crimean Congo fever, which can be fatal in an emergency.

Mosquitoes benefit from high temperatures
A total of 50 different species of mosquitoes from seven different genera live in Austria. The mosquitoes are kept apart by appearance, habitat, or host preference. Houseflies in particular are an annoying disturbing factor when falling asleep, but can also be dangerous as carriers of the West Nile virus.

Exotic species, such as the exotic Asian tiger mosquito, are increasingly appearing. It is increasingly displacing our house bloodsuckers and, unlike house flies, is also active during the day and not just mainly at night. The invasive species first came to Austria via freight transport. Mild temperatures encourage these mosquitoes to lay their eggs even in winter, AGES said.

Further spread of the striped mosquito is problematic because, like the giant tick, it also transmits tropical diseases and can transmit Chikungunya, Dengue or Zika when it bites.

Extinction of species promotes exotic invasion
“Biodiversity must not decrease. In combination with an increase in temperature, this promotes the spread of invasive species,” warns environmental doctor Hans-Peter Hutter from MedUni Vienna. The fact that the giant tick has already been spotted twice this year in this country suggests that it is already spreading. But: “Native tick species such as the wood tick are the biggest problem, because they can also transmit exotic diseases and are much more common.”