Rare wild bee discovered in the Munich-Nymphenburg Botanical Garden
June 30, 2022
Many rare and often endangered plant species are propagated and grown in conservation cultures of botanic gardens. This also serves nature conservation: Botanical gardens with their large number of plant species are also an excellent habitat for many native animal species. A very rare native wild bee has now been discovered in the Munich-Nymphenburg Botanic Garden.
For flower-visiting insects such as bees and butterflies, there is always a rich supply of food in the Munich-Nymphenburg Botanic Garden. Wild bees have been recorded since 1997, and 112 different species are currently known, which corresponds to almost half of all wild bee species known in the Munich area. During a follow-up search in June 2022, the rare stem leafcutter bee (Megachile genalis) was discovered for the first time at the Munich-Nymphenburg Botanical Garden. This bee species is threatened with extinction, in recent years it was only very rarely detected in Bavaria. Until now, only six sites were known throughout Bavaria, at many of which this bee had not been seen for 80 years.
In 2020 and 2021, the rare stem leafcutter bee was already found at two sites in Munich in allotment gardens. In the Botanical Garden, it was now discovered rather by chance, but there in larger numbers: no less than four females could be observed collecting pollen.
The rare bee species collects pollen for its offspring exclusively on certain composite flower plants, especially thistles and knapweeds. And there are plenty of these in the Botanic Garden’s display collections. A special feature of this leafcutter bee is also its nest construction: it does not build honeycombs of wax – like honey bees – and also does not nest in nesting aids (“insect hotels”) like many of its wild relatives.
Megachile genalis builds its nests from cut-out pieces of leaves, which it inserts into upright, hollow plant stems (for example of bulbous plants, cardoons or thistles), into which it has previously gnawed a hole at the side. In the Botanical Garden, efforts are being made to preserve the nests of the species, so that the rare bee species can hopefully be observed there in the coming years.
Dr. Andreas Fleischmann
Research associate and curator at the Botanical State Collection Munich
Menzinger Street 67
80638 Munich, Germany
Phone: 089 17861-240
Photo header image: Dr. Andreas Fleischmann