With a body length of up to 53 millimeters, the Heldbuck is not only the largest beetle in the Bavarian forests. But it is also the rarest. For the past 70 years, Cerambyx cerdo, the scientific name of the species, was only found in Luisenhain in Bamberg, a park at the southern end of Regnitz Island in the city. So it’s no wonder that the once not so rare beetle has long been threatened with extinction.
Cerambyx cerdo, which lives in sunny, light oak forests, has now been detected again for the first time at a second location in Bavaria. 50 kilometers as the crow flies west of Bamberg in an oak forest near Kolitzheim in the Schweinfurt district. At the State Institute for Forestry and Forestry in Munich-Freising, where experts like Anna Kanold look after biodiversity in the Bavarian forests, they classify the discovery as a sensation.
Cerambyx cerdo, also known as the great gemsbok or great oakbuck, is brown-black. Only the tips of its wing coverts are a little lighter and turn reddish brown. What is striking are the long antennae, which in males can be twice as long as the body. “The females lay up to a hundred eggs in the furrowed bark of old, often damaged oak trees,” says Kanold. The larvae hatch after just 14 days. They have a development period of three to five years and eat their way through the entire trunk. That’s why the Heldbuck was long considered a pest among foresters and forest farmers.
The beetles themselves are active from May to August in warm evening and night hours. They also whiz around in the air. But they rarely spread beyond one habitat. The hero buck always uses the same breeding tree for many generations over decades and only looks for a new one in its immediate vicinity when the old one dies.
The current evidence is a chance find and thanks to a retired forester. While walking in the forest near Kolitzheim, Reiner Seufert discovered noticeably large drill holes in an old oak tree. When he inspected them more closely, he uncovered a freshly dead, pupated beetle larvae from one of them. A DNA analysis carried out by the LWF confirmed the forester’s suspicions. It was actually a larva of the extremely rare Heldbuck. They are extremely pleased with the LWF. “The find shows once again how valuable our local oak forests are for biodiversity,” says LWF boss Peter Pröbstle. The Heldbuck is considered a so-called umbrella species for many other beetle and insect species, but also bats, woodpeckers and other animals that mainly occur in oak forests.
For this reason, the Heldbock is strictly protected not only in Germany, but throughout Europe. The EU member states have not only committed themselves to regularly recording and at least maintaining the few stocks. But also to ensure that the species spreads more frequently again. That’s why attempts have been made in the past to resettle the Heldbock in oak forests outside of Bamberg – so far always in vain.