The ZSM holds one of the largest collections of Hymenoptera in the world. The Hymenoptera is a diverse groups of insects and includes the bees, wasps, and ants, but also the parasitic wasps that play an important role in nature because keep pest insect populations at a low level.
In the ZSM about two million Hymenoptera specimens are stored in a little more than 10,000 insect drawers. Standard size drawers are 41 x 52 cm wooden boxes with glass lid and a tight key and slot joint. Drawers are arranged in wooden cabinets that allow easy access to all parts of the collection.
About 10,000 drawers are arranged in wooden cabinets.
The collection hall is underground and has no windows, keeping the risk of pest intrusions at a minimum. The floor space of the hall is about 200 m², an area smaller than a tennis court (261 m²). Climatic conditions (20°C, 45% rel. humity) are controlled and monitored using dataloggers, providing optimal conditions for the long-term storage of insect specimens. The insects were collected over a time period of more than two centuries, but even the oldest specimens, collected in the 18th century, are often in perfect condition.