It has been a special year for the mosquito fighters at Nedre Dalälven. Now that the area has been flooded for the fourth time in the same summer, the stock of pesticides has run out.
– It has been an exceptional year, says combat leader Martina Schäfer.
Already last week, the problems at Nedre Dalälven started due to the rain. The pesticide clumps together in the containers when it rains.
– We lost quite a lot of time on that and at the same time the water started to rise again. Now there are incredibly large floods in the Dalälven, it is a flow that we have almost never seen before, says Martina Schäfer.
Insufficient
Since it is a large geographical area, the pesticide is not enough for one more operation. It is not possible to have any large stocks, because the pesticides only have a certain shelf life, she emphasizes.
It will also not be possible to obtain more funds in time, as the delivery time is three months.
– What we have left is not enough in the long run, says Martina Schäfer.
She is sure that this will result in more mosquitoes, but how bad it will be for those who live in the area is still unclear.
Fourth time
The number of mosquito larvae that hatch after a new flood usually gets a little smaller with each new flood in the same season and now we are in the fourth flood since May.
It is also uncertain to what extent the mosquitoes that hatch in the floodplain wetlands find their way into communities.
TT: How has the mosquito summer been so far at Nedre Dalälven?
– It has varied. In some places it has been very good and in other places you have experienced some mosquitoes.
In Klarälven, however, mosquito control is in full swing in Forshaga municipality. It is a geographically much smaller area, which also has its own stock of pesticides.
FACT Flood mosquitoes
In the flood areas of the Lower Dalälven, it is above all flood mosquitoes of the species Aedes sticticus that are combated.
Flood mosquitoes lay eggs on moist soil. In case of flooding and a temperature of eight to ten degrees, larvae hatch, which develop quickly.
After two weeks or less, the females are ready to fly. When they have mated, they seek blood from residents or visiting people in the area.
During one and the same summer, several generations of flood mosquitoes can develop. They are aggressive biting mosquitoes, which are active even in the sun and in the middle of the day. They can fly in large numbers for up to a mile to find blood.
At the Lower Dalälven there are six more species of flood mosquitoes.
Source: Biological mosquito control (mygg.se)
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