Aedes albopictus - the Asian tiger mosquito

The Asian tiger mosquito gets its name from its contrasting black and white scales, especially on the legs (see picture). Aedes albopictus has its ancestral home in subtropical-tropical Southeast Asia and, along with Aedes aegypti, the yellow fever mosquito or African tiger mosquito, is the most successful species in terms of its spreading potential. Starting in Southeast Asia, it has established itself in parts of North, Central and South America, Africa and Europe over the last few decades. In Europe it was first detected in Albania in 1979. It was probably imported from China. It did not spread further from there until 1990. Only after its massive introduction to Italy in 1990 through the international used tire trade was it able to settle very quickly throughout Italy and from there spread throughout the Mediterranean region via private and public transport (rail and ferry traffic). The females lay their eggs in car tires, where they can survive for months. When water collects in the tires during rain, the larvae hatch. The mosquito is increasingly being transported across the Alps as a “stowaway” in cars and trucks. It can regularly be found as a flying insect along the highways coming from Italy. Egg clutches could also often be found; today, eggs of the Asian tiger mosquito can be found at almost every second rest area along the A5, so that one can assume that there is a native propagation. The good adaptability of this originally subtropical mosquito species to its new environment, e.g. B. to the climate in temperate latitudes through the adaptation of their life strategies and climate changes, have favored their spread. The spread in southern Germany is particularly dramatic. The first stable population was discovered in Freiburg in 2014. In 2017, there were already 7 municipalities that were infected with Aedes albopictus. In 2021 there were already more than 30 municipalities. The northernmost occurrence is in Berlin.

The tiger mosquito breeds in small and tiny accumulations of water, for example in: rain barrels, buckets, watering cans, flower pots, saucers, water bowls, water-filled umbrella stands, drains, clogged gutters, car tires. The eggs survive drought and even cold winters.

The following are not breeding grounds: Lively garden ponds with fish, newts, etc. Bird and hedgehog baths are also not breeding grounds if the water is changed at least every five days.

The settlement of new areas is increasing rapidly, so extensive control measures are being taken by municipalities to prevent severe nuisance or even transmission of viruses. At the moment, virus transmission is still unlikely, but cannot be completely ruled out.

After the tropical Aedes aegypti (the yellow fever mosquito), the Asian tiger mosquito is the most important vector of arboviruses (arthropod-borne viruses). The more than 22 types of viruses that can be transmitted by Aedes albopictus include chikungunya, dengue, yellow fever and West Nile viruses. Chikungunya fever epidemics are known from Réunion and India, where more than two million people have been infected by Aedes aegypti bites. The first epidemic of this tropical disease occurred in Italy in 2007. After an infected person traveled from India to the Ravenna region, around 250 cases of the disease occurred within a few weeks. The chikungunya virus was detected in Aedes albopictus, making the Asian tiger mosquito the first vector of a tropical disease in Europe. In recent years, there have also been isolated transmissions of the Chikungunya, Dengue and Zika viruses in the Mediterranean region.

Aedes japonicus - the Japanese bush mosquito

The Japanese bush mosquito (Aedes Ochlerotatus japonicus) is native to Japan, Korea, southern China, Taiwan and the east of the Russian Federation. In Europe, it was first found in France in 2000 and in Belgium in 2002 in a used tire warehouse. In 2008, the mosquito was found in northern Switzerland and Baden-Württemberg, and later also in Rhineland-Palatinate, North Rhine-Westphalia and Lower Saxony. The climatic conditions in the countries of origin of Aedes Oc. japonicus in East Asia are similar to the climate in Europe, which favored the establishment of this species in Germany. Today, this species is widespread in Germany. Its most important breeding sites are natural erosion in the rock (which is why it is sometimes referred to as the Asian rockpool mosquito), tree hollows and artificial water collections, e.g. fountains, flower vases or rain barrels. The species must be considered an already established species for Germany, as it has produced at least three generations in its new environment. The introduction of Aedes Oc. japonicus is most likely due to the import of goods such as old tires or in connection with ornamental plants or flower vases from Asia (China).