In May, an unusually large area of around 10,000 hectares was combated in seven municipalities; Sala, Avesta, Heby, Gävle, Sandviken, Älvkarleby and Tierp. In connection with this, Jan Lundström, operations manager at Biological Mosquito Control, said that the summer was saved thanks to the efforts. But according to residents and summer cottage owners that SVT talked to, the summer has been a scourge – a mosquito plague.

"It's only now that things have begun to calm down," says Stefan Pettersson, who owns a summer house on Ön at Öster Bännbäck in Sala municipality.

In the clip: "This year has been a disaster" – therefore areas along the lower Dalälven river have been affected by mosquitoes despite major control efforts.

Mosquito fighters' concerns: "Then we have no means left"

Javascript is disabled

Javascript must be turned on to play video

Learn more about browser support

In several places, but not everywhere – here the third mosquito control takes place at the lower Dalälven. Photo: Niklas Hagman