Mosquito plague on the Upper Rhine: Hunters rely on bio-weapons against gnats!

Mosquito plague on the Upper Rhine: Hunters rely on bio-weapons against gnats!

In recent weeks, heavy rainfall in Baden-Württemberg has caused unpleasant surprises. The rainfall has not only transformed the landscape but also created the ideal environment for mosquito larvae to form. As the daily news According to reports, mosquito hunters are working in three federal states to get rid of the plague. There was a massive hatching of the little pests, particularly on the Upper Rhine.

The conditions for the riparian forest mosquitoes could hardly be better. Flood events like the recent ones significantly promote their development. After a dry spring, flooded depressions and floodplains provided ideal breeding grounds. No fewer than 100 to 200 larvae per liter were detected during scooping checks in the affected areas.

The combat strategy

The municipal action group to combat the mosquito plague (KABS) had already taken active measures before Pentecost. The biological active ingredient Bti (Bacillus thuringiensis israelensis) was used, which works effectively against the larvae without unnecessarily polluting the environment. Smaller areas in the Rhine floodplains were treated on foot, while larger areas were sprayed with the ice granules by helicopter.

The focus of the combat operations was in the Rastatt area and the southern Palatinate. The first measures were also implemented north of Karlsruhe on the Wednesday after Pentecost, and similar operations followed in Hesse a day later. The first samples show promising results, and the situation in the affected riparian forests has already improved significantly.

Ecological considerations

But in the shadow of these control measures there is also an important discussion about the ecological effects. According to that Federal Nature Conservation Association Mosquitoes are not only annoying, but also play an important role in the ecosystem. Larvae serve as food for fish, while adult mosquitoes serve as a food source for birds and bats. A comprehensive fight could therefore endanger natural communities.

In addition, the use of Bti is viewed critically. Although Bti specifically targets mosquito larvae, its use could also have negative effects on other insects and amphibians. Using butterflies for control could also reduce the food supply for many animals during the breeding season. The federal government therefore demands that Bti not be used in nature reserves and protected biotopes.

Social responsibility

The Federal Environment Agency (UBA) has received increasing inquiries about larvicides and emphasizes how important it is to educate the population about the effects of mosquito bites and possible disease transmission. While Asian tiger mosquitoes can transmit viruses, fortunately no native cases of the disease have occurred in Germany, but there have been some cases of West Nile virus transmitted by domestic mosquitoes since 2019.

Fighting mosquitoes can be useful if it is carried out correctly and sustainably. The UBA informs that small-scale applications of Bti are not expected to have negative environmental impacts as long as they are used correctly. However, alternative measures, such as reducing breeding sites and encouraging natural predators, are equally important.

Ultimately, a balance must be found between combating annoying mosquitoes and preserving our valuable ecosystems. As the current situation shows, there really is something going on – both for mosquito hunters and for conservationists.