“There is an imminent risk of a mosquito explosion,” said Biologisk Myggkontroll, an organization working to help control the mosquito population around the lower Dalälven River, in a statement.

“We hope that people and pets in these villages will have a tolerable summer. In the past, the situation was insufferable.”

On Monday, a helicopter started spraying more than 2,000 hectares of wetlands in hopes of striking the mosquitoes down before they can launch a counter attack against a defenceless Swedish populace.

The treated area has been expanded this year and marks the largest area sprayed since anti-mosquito efforts began.

Experts hope that the treatment will make the summer more livable for people residing in mosquito-infested areas.

“Estimates show that there is currently a very large number of mosquito larvae along the lower Dalälven River,” explained Biologisk Myggkontroll.

“Right now water levels are high and warm weather is on its way, which would create an extremely favourable situation for the mosquitoes.”

The selected areas will be sprayed with Bti (Bacillus thuringienis israelensis), a biological agent that breaks down mosquito larvae’s digestive tracks and prevents them from hatching.