Once one of the largest entomological collections in Germany, the Zoological Museum suffered greatly from the loss of essential parts of its collection in 1943 which was assumed to house in this department up to then about 1.5 million insects, with an estimated 10,000 types. Parts of these historical collections, going back to the time of Hanseatic merchandisers with their interest in natural history collections, were rescued while important parts of the collection, such as of holometabolic insects with many types, were destroyed. Today, CeNak’s entomological collection holds again up to approximately 5 million specimens, either pinned and in alcohol, supplemented by well over 6,700 microscopic samples and 500 artificial insect models, and about 10,000 types, with a focus on Heteroptera, Trichoptera, Coleoptera and Lepidoptera, rendering it one of the largest and most important among German museums.
The international significance of the collection is reflected by frequent guest scientists and loan requests. Collected from all around the world, containing numerous unique specimens, the collection is subdivided into three sections: the scientific-systematic collection, scientific special collections (including insects that damage plants and textiles), and a comprehensive teaching collection. Only a very small fraction of its holdings is catalogued and/or digitalized. A current working focus is set on the digitization and photographing of all type specimens as well as the establishment of a database from tens of thousands scanned catalogue cards. As of 2020, more than 70,000 entries were digitized and that number is continuously growing.
The collection is growing on average by more than 100,000 specimens per year and, thus, continues to document the biodiversity of insects, the largest class of animals on Earth. Edited by H. Strümpel and H. Dastych the Entomological Department published its own journal “Entomologische Mitteilungen aus dem Zoologischen Museum Hamburg” for many years. The journal is continued within the re-launched journal “Evolutionary Systematics” published for the entire Zoological Museum in Hamburg.