20 years of mosquito control

How mosquito abundance in the village of Österfärnebo has changed:

The diagram shows an example of mosquito abundance in the Nedre Dalälven region before and after the start of floodwater mosquito control in the year 2002. In the village of Österfärnebo, an enormous abundance of mosquitoes was documented in the summer of 2000 with a maximum of 23,000 mosquitoes per trap and night. Compare this to recent years which yield a maximum of 490 mosquitoes per trap and night. Our goal of reducing mosquito abundance below 500 individuals per trap and night has clearly been achieved.

Variation in floodwater mosquito abundance is related to the frequency and magnitude of floods during the spring and summer. The blue area of the diagram shows the flow rate of the River Dalälven at Långhag monitoring station which is located upstream in the Nedre Dalälven region. Floodwater mosquito control with VectoBac G has resulted in a drastically reduced and tolerable quantity of floodwater mosquitoes even during years with large and numerous flood events (2008, 2009, 2010, 2012, 2015, 2018, 2021 and 2023). In such years, production of blood-sucking floodwater mosquitoes would have been massive without our successful VectoBac G treatments. Some years, no floods occurred during spring and summer (2011 and 2013) and in these years no control measures were needed.