Mosquitoes in Sweden

In some areas of Sweden, there are many more mosquitoes than we are used to in Denmark. This is especially true in forest areas, meadows, wetlands and the like.

In Sweden, there are also around 50% more species of biting midges than in Denmark.

In addition, the number of biting mosquito species (other than biting midges) can be greatly increased during certain periods. All of these factors mean that in some places in Sweden, mosquitoes are being actively controlled - both privately and Associations.

If you are going to be in the Swedish countryside, it is therefore recommended that you always bring mosquito repellent, mosquito nets and full-coverage clothing.

Aedes vexans is (along with Aedes sticticus) one of the most aggressive mosquito species in Sweden

Credit: Sean McCann -

Aedes vexans is one of the most aggressive mosquito species in Sweden


Tips for tourists in Sweden

Although there can be a lot of mosquitoes in some areas of Sweden, it depends a lot on the weather and the local area. There are generally more mosquitoes in the northern parts of Sweden than in the south - but with the right weather conditions, there can still be extremely high mosquito numbers in southern Sweden!

If you're spending time in nature - such as canoeing, camping or hiking - you should obviously be more careful than if you're on a city break.

Below are some tips for avoiding mosquitoes and mosquito bites in Sweden:

  • Jungle oil: Jungle Oil is a mosquito repellent that is banned in Denmark because it contains DEET. The long and short of it is that it is very effective at keeping mosquitoes at bay, but unfortunately DEET enters the human bloodstream and is likely to be slightly harmful to health (its specific health effects are therefore debated). Follow the instructions on the packaging and do not use on children!
  • Other mosquito repellentsBecause the mosquito problem is greater in Sweden than in Denmark, there are also far more and more effective mosquito repellents on the Swedish market. It is therefore advantageous to buy your products in Sweden rather than Denmark. This applies to both mosquito repellents and mosquito bite treatments (Salubrin ointment is particularly recommended for mosquito bites).
  • Mosquito netsMosquito nets are one of the best things to buy from home. Prices for mosquito nets vary greatly depending on the time of year and location; for example, if you buy mosquito nets in the middle of summer at a campsite, for example, you'll end up paying far more than you need to.
  • Tent: If you will be sleeping in a tent, avoid pitching your tent in damp areas or stagnant water (such as forest lakes, ponds, ditches, troughs, pools, etc.) Long grass and dense vegetation should also be avoided.
  • WeatherHot humid weather - especially with alternating dry and rainy periods - is ideal for mosquitoes. Therefore, it's a good idea to check the weather forecast before heading out.
  • EveningAlthough some mosquito species are active during the daytime, the vast majority of biting midges are most active in the evening hours - especially around dusk. Therefore, you can limit your outdoor activities during these hours. At night, mosquito activity levels decrease.


Mosquito species in the Swedish fauna

In Sweden, there are far more registered mosquito species than in Denmark:

  • Total mosquito species: There are over 2500 mosquito species in Sweden (there are over 1600 in Denmark)
  • Species of mosquitoes: There are 47 species of biting midge in Sweden (there are 30 - 35 in Denmark)

Note that the figures above only apply to registered mosquito species and that the total number of mosquito species in both Sweden and Denmark is most likely much higher. However, the number of biting midge species is more accurate.



Overall, it is the biting midges that bite humans the most in Sweden. In Denmark, we often divide mosquitoes into 4 groups (see also our article about mosquitoes in Denmark here), mosquitoes in Sweden are typically divided into 10 groups according to their biology - i.e. where they lay their eggs, where they overwinter, who they suck blood from and how many generations they can produce per year.

The two largest groups forest mosquitoes (en: forest mosquito) and flood control mosquitoes (sv: översvämningsmygg).p These two groups contain the majority of the species that sting humans and are therefore also the ones we will discuss below.


Fungus gnat

In Sweden there are 17 species of forest mosquitoes (in Denmark we have 4-5 species) and are the most widespread of all biting midges. They are also the most common and the vast majority of mosquito bites in Sweden are caused by these mosquitoes.

Most adult mosquitoes are present in the summer months, but already in late summer their population begins to decline significantly. Forest mosquitoes have only 1 generation per year and move a maximum of 2 km from their breeding sites.


Flood mosquitoes

Flood mosquitoes lay their eggs on land that is subsequently flooded. The eggs can remain dormant for several years while they await the right conditions to hatch. In practice, the eggs must first be exposed to drought and then flooded with water in order to hatch. The larvae develop after each flooding and during a rainy summer, several generations can hatch.

There are 7 species of floodwater mosquitoes, but in each local area, one or two species typically dominate. The most aggressive species are Aedes sticticus and Aedes vexanswhich can fly far away from their breeding grounds. Unlike many other mosquitoes, they can also attack humans during sunny daylight hours.



Mosquitoes in Sweden can infect humans with the so-called ockelbosyge (it is also called berry-picking disease or pogostasis in Finland). The Swedish designations are ocellosisberry-picking disease and pogostasis. It is especially the house mosquitoes in the families Culex and Culisetawho carry the disease.

The disease is caused by the Sindbis virus, which is spread by mosquitoes, who probably contract it after biting other animals (presumably birds).

The typical patient is a middle-aged person who has been bitten by a mosquito while berry picking in late summer or fall in either Sweden or Finland. There are approximately 100 cases per year and major outbreaks occur every 7 years.

There are no vaccines or medications for ocellosis. The only thing you can do is try to avoid mosquito bites by using mosquito repellents and full-coverage clothing.