Invasive mosquito species – new mosquitoes in Europe

Mosquitoes have existed in Europe for thousands of years, but in recent decades several new invasive mosquito species have begun to spread in the region. These species originally lived in other parts of the world but have established themselves in Europe through international trade, transportation, and climate change.

Many of these mosquitoes differ from the species traditionally found in the Nordic region. They may have different behaviors, different habitats, and in some cases even the ability to spread diseases that have not previously occurred in Europe.

In this guide we cover:

• what invasive mosquito species are
• how they spread
• which species are most common in Europe
• what risks they may pose
• how researchers and authorities monitor them

What is an invasive mosquito species?

An invasive species is a species introduced into an area where it did not previously exist naturally and then begins to spread and establish populations.

Regarding mosquitoes, this often means the species:

• is transported to new areas by humans
• can survive the climate in the new area
• finds suitable places to lay eggs
• starts reproducing locally

Many invasive mosquito species belong to the genus Aedes, which also includes several species known to be capable of spreading viruses between humans.

This does not mean all invasive mosquitoes spread diseases, but some species have the biological capacity to do so under the right conditions.

How do invasive mosquito species spread?

The spread of invasive mosquito species almost always occurs through human activity. Mosquitoes can travel long distances via various types of transport and goods.

The most common pathways are:

International trade

Eggs from certain mosquito species can survive for a long time in dry environments. This allows them to be transported in, for example:

• car tires
• containers
• plant transports
• bamboo or ornamental plants

When the eggs then come into contact with water, they can hatch.

Transport and travel

Mosquitoes can also hitch a ride in:

• trucks
• ships
• airplanes
• tourist trips

This allows species to be quickly moved between different countries.

Climate change

A warmer climate enables some species to have better survival chances in Europe.

Temperature, precipitation, and longer summers can create conditions that allow new species to establish further north than previously.

What risks do invasive mosquito species pose?

Most invasive mosquitoes mainly cause increased irritation and more bites.

But some species can also have medical significance as they can act as vectors, meaning carriers of viruses.

The risks depend on several factors:

• whether the virus is present in the area
• how many mosquitoes there are
• how often people get bitten

In Europe, local outbreaks of diseases such as dengue and chikungunya have occasionally been seen in areas where the tiger mosquito has established.

The risk of major disease outbreaks in northern Europe is currently very low.

This is partly due to:

• the climate
• limited establishment of relevant mosquito species
• effective surveillance systems

However, researchers closely monitor developments since climate and global trade can change the situation over time.

Common invasive mosquito species in Europe

Several species have established themselves in Europe over the last decades. The best known are:

• Asian tiger mosquito (Aedes albopictus)
• yellow fever mosquito (Aedes aegypti)
• Japanese bush mosquito (Aedes japonicus)
• Korean bush mosquito (Aedes koreicus)

Another mosquito different from the common forest mosquito is the so-called subway mosquito, often called the London Underground mosquito (Culex pipiens f. molestus). It is not considered an invasive species but is still interesting as it is cold-intolerant and has adapted to living in urban environments.

Sammanfattning

Invasiva myggarter är myggor som spridits till nya delar av världen genom mänsklig aktivitet. Flera sådana arter har under de senaste decennierna etablerat sig i Europa.

Den mest kända är den asiatiska tigermyggan, men även arter som japansk buskmygga och koreansk buskmygga förekommer i regionen.

Även om vissa arter kan sprida virus är risken för större sjukdomsutbrott i norra Europa fortfarande låg. Samtidigt följer forskare utvecklingen noggrant eftersom klimatförändringar och global handel kan påverka spridningen i framtiden.

Genom övervakning, forskning och förebyggande åtgärder går det att bättre förstå och hantera dessa nya myggarter.