Dear researcher
I have the following question: If there were more bogs in Switzerland again, wouldn’t that lead to there being more tiger mosquitoes? I understand that bogs are good for the environment. But at the moment, we’re also receiving a lot of advice telling us to empty all containers of standing water, such as watering cans or plant pot saucers, so that tiger mosquitoes cannot lay their eggs there.
Many thanks
Paul Vonarp
Dear Mr Vonarp
Thank you for your question. I am an expert on moors, not tiger mosquitoes. Nevertheless, I am happy to answer your question. Because yes, as temperatures rise, so do various diseases. Nor should the heat stress itself be underestimated.
Current research project
On the topic of climate change and health, a research programme has launched a project entitled “Climate Change and Health” has been carried out as part of a research programme, and its findings will be published shortly: amongst other things, an information sheet on the tiger mosquito is due to be published. I think it should be out in the next few months...
Artificial water sources as breeding grounds
Now, to answer your question specifically: Yes, tiger mosquitoes breed in small bodies of stagnant water. But it is actually the case that artificial water sources (watering cans, flowerpots, etc.) are the places where they mainly breed (the authorities therefore do not hold private individuals accountable without taking action themselves; artificial water sources are in fact the most important breeding grounds).
Predators in natural water sources
In moors, it would only be the open water areas, of which there are permanently few in natural raised bogs. In drained moors, on the other hand, there is often standing water in the drainage ditches. However, neither the open water bodies in natural moors nor the ditches in drained moors are the main problem. After all, many other species (dragonfly larvae, amphibians, etc.) live there and feed on the mosquito larvae.
Rising temperatures as a cause
One of the main causes of the spread of the tiger mosquito is rising temperatures. Accordingly, it makes a great deal of sense to rewet the moors in order to reduce the CO₂ emissions they release when drained.
In summary: there is already standing water in drained moors (in the ditches). However, it is in these that the tiger mosquito’s eggs are mainly eaten. The major breeding grounds are in “artificial” water bodies, where they are undisturbed.
Best regards
Lena Gubler