From flood ponds

Now the “fall jellies” are swarming out en masse

Floodplains that have not been seen for a long time are now awakening pesky bloodsuckers from clutches in abundance.(Bild: G.I.Bernard/OSF/OKAPIA)

Even in the remotest corners and after up to 10 years of drought, they are waiting for this one chance - which the shallow residual flooding areas of the flood of the century are now offering them: Autumn jellies are currently hatching en masse from egg deposits and are programmed by nature for just one thing: to quickly find a blood donor. 

They are ready to take off at any time, well-tempered water is sufficient even in the fall - and now the time has come: Since so-called flood jellies have already passed the embryonic stage in their egg, they are quick to emerge when they come into contact with moisture: Get out of the larva and take off as soon as possible. Clutches that have left their parent generation in areas once flooded by high water can even survive for up to 10 years in dust-dry conditions. And the pools of water from the recent flood disaster in Lower Austria are now awakening the bloodsuckers to "fly out" again, even in the most remote areas.

A small pond of water can bring countless larvae back to life - even now in the fall.(Bild: Andi Leisser)

March jellyfish guards launched a defensive flight with a helicopter
On the March, where the pesky insects are being closely monitored, a helicopter was recently sent out with the BTI control agent, as Katharina Wessely from the "Biological Gelenium Control March-Thaya-Auen" association reports. Because in the regions that are often only a few centimeters flooded, one day of sunshine is enough to exceed the "hatching threshold" of 8.5 degrees, says Wessely.

Not disease carriers, but more annoying than all the others
Bernhard Seidl also confirms that these "buzzing late bloomers" are particularly annoying: "They are also vehemently on the lookout for blood protein to reproduce during the day," explains the "mosquito doyen". He names the Tullnerfeld plus regions to the east of Vienna and parts of the Mostviertel as very affected areas in addition to the March. If there are any advantages to the situation: These are not incomparably more dangerous tiger mosquitoes, their late clutches do not survive the winter and, quicker than their spring counterparts, are soon swarmed again ...