For the first time in 74 years a rare Jucht leather beetle has been spotted in the Netherlands. The animal, which lives hidden in hollow trees, was seen in Kerkrade, reports Nature Today Monday. The red leather beetle and its habitat are strictly protected by inclusion in the European Habitats Directive.
According to the Juchtlebeetle Nature Today fourteen historical sites known in the Netherlands. The last sighting was from 1946, in South Limburg. By coincidence, the beetle was found by zookeepers in GaiaZoo in Kerkrade in early August.
The animal was sitting on a path near a huge hollow, pollarded white willow tree. Targeted searches in the ensuing period yielded a few more specimens, all of which were in the same willow tree. There are more potentially suitable trees in the immediate vicinity, but no beetles have been found here so far.
The red leather beetle lives in mud in the hollows of thick deciduous trees. The species is quite picky: the wood dust must occur in a considerable volume, be constantly moist, have a decent temperature and contain the right fungi.
The beetle lives in closed tree trunks
Due to the need for heat, living trees are almost always inhabited that are located in semi-open biotopes such as tree gardens or forest edges. It is not surprising that since old, standing hollow trees are less common, the Jucht leather beetle is also much less common.
The fact that the Jucht leather beetle is rarely seen has not only to do with its rarity: the beetle lives very hidden. The larvae live in the sludge for three to four years, up to a meter deep. Even the adult beetles hardly emerge from their breeding tree and reproduce in the exact same location where they were born.
Only a small portion of a population leaves the tree in which they were born to deposit eggs in another tree. The animals that look for another place rarely move more than a few 100 meters. They are therefore extremely local, hence the generic name eremita, which means hermit (hermit).
It is unclear where the animal suddenly came from
A population can reside in one and the same tree generation after generation and be part of a metapopulation, which is located in similar trees within a radius of several hundred meters. That’s exactly what makes the species particularly vulnerable to habitat loss and fragmentation.
The question is why the Juchtlebeetle suddenly reappears in South Limburg. Experts are not sure about this yet. It can certainly not be ruled out that the species has never left and has survived in low density or extremely locally.