The Hemimetabola Collection maintains much more than a million specimens. Hemimetabola describes insects with incomplete development, as found in bugs, cicadas, termites, cockroaches and grasshoppers. This is a historical category, based on similarities in the development of individuals in which juvenile stages very much resemble the adults. It does not designate genetic relatedness.
Bugs and cicadas (hemiptera) provide the largest proportion of species and individuals - 620,000 and at least 11,000 species. There are holotypes of approximately 2,000 species. The Orthoptera collection comprises approximately 300,000 specimens and 3,000 primary types – which makes it one of the most significant grasshopper collections worldwide and the largest in Germany. There is also a historical collection of plant galls caused by a variety of insect groups.
The collection also includes primarily wingless insects such as jumping bristletails (Archaeognatha) and fishmoths (Zygentoma). Two-pronged bristletails (Diplura), springtails (Collembola) and coneheads (Protura), which, like insects, are Hexapoda, are also part of the collection.
The collection material is mostly stored in insect cases as pinned dry specimens. In addition, there are numerous microscope slides, especially of bird lice (Mallophaga). A considerable proportion of the specimens is stored in alcohol, comprising approximately 13,000 jars – the most comprehensive entomological collection at the Museum.
The collection has a worldwide scope, with a geographical focus on Africa, in the historical as well as recent collections. Furthermore, there are many specimens from South America, the Middle East and Palaearctic region (Northern Africa and the entire Eurasian region) in the collection.