Director´s view

Miroslav Bobek  |  30. 09. 2015

There is always something to discover. Also in a zoo. When I asked Pavel Krásenský, zoologist and photographer to document the lives of insects in our Zoo, I hoped that he would discover something interesting. But reality exceeded expectations.

Photo: Pavel Krásenský Photo: Pavel Krásenský

Besides many other rare and unique arthropod species Pavel discovered here an absolutely extraordinary critter, who is the largest member of its family. He observed him only for the second time in his life, which, regarding his experience, speaks for itself. On an oak at the upper part of the Zoo he managed to discover the largest of the about five thousands known aphids. Real mega-aphid! It grows to up to eight milimeters, therefore it is often compared to a coffee bean. If common aphid species were the size of a passenger car, this aphid would look like a fire truck next to them. Its proboscis is twice as long as the body, so if we count it in total length, we would reach three centimetres. Thanks to this size it received its common name - Giant Oak Aphid - but the world knows it under its scientific name, Stomaphis quercus.    

I had no idea that such a large and weird aphid exists. And if I had, I would have expected it to live somewhere in tropical area, not in Troja. Unbelievable! Immediately after I learned about its discovery I left for the Zoo. I did not have to search the oak, where the Giant Aphids live; it is right next to one of the enclosures. But it was harder to find the Giant Aphids. Large shiny black ants of Laisus genus, who breed the aphids for their honeydew, are hiding them in deep crevices of oak bark. But the aphids are there! One by one or in groups, grey-brown coloured, the size of a large grain of rice to the already mentioned coffee bean. Mega-aphids - Giant Oak Aphids.

After all, you can also try to find them. But I will not release the exact location; I am still a little worried about them. However, this year you don´t have a lot of time, because before the winter the ants will hide their Giant Aphids somewhere into the roots of the oak - and nobody will be able to see them there.

Photo: Pavel KrásenskýPhoto: Pavel Krásenský