In many parts of the country, the winter and spring have been dry and groundwater levels are low. Mosquitoes in the forest have therefore had few, small puddles in which to hatch, according to Anders Lindström.
There are always places where it has been humid enough for mosquitoes to hatch anyway, but in many places the first mosquito swarm will be smaller than average, Lindström says.
Other mosquitoes that hatch later in the summer in permanent water, such as ponds and lakeshores, are not as severely affected by the drought.
Then there may be another surge, but they are usually never as numerous as the first wave, Lindström says.
Active in heat
Essentially, it is the humidity that affects how many mosquitoes hatch, but the weather also determines how much we notice them.
If it is very hot, the mosquitoes that have hatched will be very active and can be noticed more than if it is cooler. If it is dry, they tend to stay in the shade where it is a little more humid.
He advises anyone who wants to reduce the risk of bites to use approved mosquito repellents.
Then it depends on how sensitive you are. If you are bothered by mosquito bites, you may have to wear long sleeves and long pants even if it's hot.
Affects species
This year's forecast is probably welcome news for everyone plagued by mosquitoes, but according to Anders Lindström, fewer mosquitoes are not the only positive thing.
There are no animals that are specialists in eating only mosquitoes, but many eat them anyway. If there are fewer mosquitoes, they will have to eat something else and this could increase pressure on other species.
He also notes that prolonged drought negatively affects many other animals.
During the dry year of 2018, two butterfly species became extinct in Sweden because the larvae's host plants withered and died in the drought.
