Very few Munich residents will have come face to face with a densely punctured roller neck block. On top of that, many would not realize that this is a native species of beetle. “We are noticing that knowledge about nature and the animals that populate it is decreasing, although the information options are constantly increasing,” says Rudolf Nützel, managing director of the Munich district group of the Bund Naturschutz (BN).
The BN and the municipal department for climate and environmental protection therefore present a selection of unusual beetles or beetles that are particularly interesting in terms of their way of life in the free brochure “Beetles in Munich”. It is the ninth project in this series and is intended to invite children, young people and adults to get to know their environment better.
“It’s an invitation to experience nature. If you look closely, you can discover a lot,” says Nützel. An unimagined variety of beetles lives right on the doorstep, in gardens and parks, but above all in near-natural biotopes. According to Nützel, there have been around 1,800 different species of beetles in the Munich city area over the past 200 years. However, the population has declined: since the turn of the millennium, only two thirds of the number, i.e. around 1200 species, have been recorded. In general, a few conspicuous beetle species are known.
Climate change is killing some species and reviving others
The brochure is intended to encourage people to work with strangers – or who has ever heard of the iris weevil, the musk beetle or the four-spotted bark worm? “You notice the climate change,” says Nützel. “Some species are going extinct, while other beetle species that have never been there are establishing themselves.” In addition to the external characteristics and special features of the beetles, the brochure also tells you where the beetle species can be found.
In Munich there are a wide variety of habitats for the most species-rich group of insects: the acorn borer lives in forests such as the Truderinger Forest. The map weevil inhabits dry biotopes such as the Fröttmaninger Heide. In wet areas like the Moosschwaige you can find the iris weevil and on the dry gravel banks of the Isar you can observe the gravel bank sandpipers. “Beetles are a very important part of biological diversity in Munich. In our increasingly intensively used agricultural landscape, diverse urban biotopes are important oases not only for groups of insects such as beetles, but also for the city’s population,” says Nützel.
The majority of beetle species are important links in the food chain and ecological cycles. In addition, experiencing nature as a counterpoint to the hectic hustle and bustle in the big city to slow down is becoming increasingly important, says Nützel. If you look closely, you might recognize one or the other representative of the beetle species on your next walk.
stag beetle
The larvae of the stag beetle eat through roots for seven years.
(Photo: Ingrid Altmann)
It’s not easy to overlook the stag beetle – if you do see it. The largest Beetle in Germany has become rare. The male is unmistakable because of his antler-like upper jaw. “A huge insect,” says Nützel. The last time a specimen was sighted in the Allacher Lohe was in the 1990s. After finding the remains of dead stag beetles, the BN has now buried oak trunks there – in the hope that females will lay eggs on the dead wood there again. “If you could observe real stag beetles in Munich again, that would be a sensation,” says Nützel.
iris weevil
The iris weevil can be found in wetlands.
(Photo: Markus Bräu)
The iris weevil is a moisture-loving beetle. It is mainly found in places where irises grow – this is where the female lays her eggs in the young fruits of the plant. According to Nützel, these are particularly nutritious. “The beetle looks like an alien with its trunk,” says Nützel. The beetles use this distinctive proboscis to bore into the plants in order to feed on them. In addition to Munich wetlands such as the Schwarzholzl and the Moosschwaige, the iris weevil can also be observed in gardens with ponds – provided that irises grow there.
musk buck
In the past, the musky-smelling secretion of the musk buck was used to perfume pipe tobacco.
(Photo: Markus Bräu)
The name of this species of beetle is due to a strong, musky-smelling secretion that the animals can secrete. In the past it was used to perfume pipe tobacco. “If you catch it in a magnifying glass, then it smells,” says Nützel. “Whether the scent is pleasant is always relative.” The musk buck is not only difficult to confuse because of its size of up to four centimeters. In the sun it shimmers in many colors: blue-violet, greenish or even bronze. In Munich it was seen in the Eggartensiedlung – the larvae mainly develop in willows.
Black sting beetle
The thorns of the black sting beetle are unique.
(Photo: Markus Bräu)
At three to four millimeters, the black spiny beetle is a relatively small species of beetle. “It’s about taking a close look,” says Nützel. Seen up close, the beetle is an eye-catcher because of its bizarre spines. The black spiny beetle lives in dry, lean grassland in sunny, warm locations. In Munich, for example, it can be seen in the Nymphenburger Park or in the Riemer Forest. “Like all beetles, they don’t want to be eaten,” says Nützel. The spikes on its body are said to make it difficult for birds to swallow the bugs.
hazel leaf roller
The larva of the hazel leaf roller develops in a self-made leaf coil.
(Photo: Markus Bräu)
The hazel leaf roller has a special way of caring for its brood. “It’s something unique,” says Nützel. The female lays the eggs in a leaf wrapping that she made herself, which serves as a cradle. “The beetle artistically cuts a leaf and then rolls it up from the tip,” says Nützel. At the end, the wrap is firmly closed by folding in the leaf tips and proboscis stitches. In Munich, the hazel leaf roller is not uncommon. It lives in particular on hazels, for example in the Nymphenburger Park or on the southern banks of the Isar.
ant-sac beetle
If the ant-sac beetle is attacked, it will play dead.
(Photo: Markus Bräu)
The larvae of the ant bag beetle grow up in ant nests. After the female has laid the eggs near an ant nest, the ants carry the supposed nest material into their burrow. “The females build a sack from their own droppings to protect them from the ants,” says Nützel. The larvae eat food leftovers and prey of the ants as well as their brood. After hatching, the beetles flee into the open. If attacked by the ants, they can play dead. The ant-sac beetle lives in Munich in rather dry extensive meadows and nutrient-poor grasslands.
Under www.bn-muenchen.de as well as below stadt.muenchen.de/infos/muenchens-fauna.html the brochure is available for download – the 48-page brochure is also available free of charge in the Department for Climate and Environmental Protection (Bayerstraße 28a) and at the BN (Pettenkoferstraße 10a).