Richardiidae are among the most strikingly beautiful of all true flies. Roughly 194 valid species in 32 genera are currently recognized, and the overwhelming majority live in the Neotropics, with only a handful stretching north into the Nearctic region. Many species carry wings painted with bold dark patterns, bodies and legs sheathed in metallic blue or greenish coloration, and a characteristic tephritoid ovipositor that makes females instantly recognizable under the microscope. Adults are frequently collected with fruit-baited traps, and larvae are thought to develop in decaying plant material, yet the family remains poorly studied compared with better-known fly groups, and many taxa are still undescribed or known only from vague historical descriptions.

That scarcity of study has long been compounded by a geographical problem. Much of the early taxonomic work on the family was carried out in Europe, by specialists such as Friedrich Hendel, Enderlein and Willi Hennig, with the resulting type specimens deposited in European museums rather than in the countries where the flies were collected. For South American researchers, whose fauna is the richest, access to these name-bearing specimens has been difficult and slow. Only a small fraction of the type material held in the Warsaw museum had ever been photographed and made available to the dipterological community, which is precisely the gap the new catalogue sets out to close.

The Stettin collection, historically associated with the city now known as Szczecin in Poland, was one of the great entomological repositories of the early twentieth century. It is often assumed to have been largely destroyed during the Second World War, but that assumption turns out to be only partly true. A significant portion of the material survived and is now preserved in Warsaw, in good condition, including type specimens belonging to multiple insect groups. The 76 Richardiidae specimens documented in the new study all trace back to this historical source. They were originally assigned to 31 species and subspecies, with two additional specimens identifiable only to the genus Melanoloma.

Every specimen in the catalogue was examined and photographed at the museum using a Leica MZ16 stereomicroscope fitted with a DFC 500 digital camera, with images processed through Leica Application Suite software. The authors paired each photograph with complete label data, transcribing the handwritten and printed labels that record where and when each fly was collected and who identified it. The specimens were also georeferenced, and the resulting dataset has been made openly available, so that researchers anywhere can connect a name on a page to a physical, verifiable insect in a drawer in Warsaw. To support finer anatomical comparisons, additional high-resolution photographs of morphological details have been deposited in Harvard Dataverse and are freely downloadable.

Among the documented material are some remarkable survivors. The holotype male of Cladiscophleps ramulosa, the type species of its genus, carries the original labels reading Santa Catharina, collected by Lüderwaldt, and Enderlein’s own handwritten determination from 1912. The holotype female of Hemixantha fasciiventris, labeled simply Columbia Pehlke, and the holotype female of Megalothoraca ferruginea from Santa Inéz in Ecuador, collected by R. Haensch, are likewise illustrated in lateral view alongside their labels. Holotypes of Megalothoraca flava and Megalothoraca undulosa, both from the same Ecuadorian locality, join them, as do the holotypes of Odontomera canonigra, Poecilomyia longicornis columbiana, Richardia hendeliana and Richardia infestans. Each of these insects is the single physical anchor for its scientific name.

Not every name could rest on a single specimen. For Megalothoraca hendeli, Enderlein based his 1912 description on three individuals without designating a holotype, leaving the species anchored to an ambiguous set of syntypes. The catalogue designates one of those males as the lectotype, formally fixing the identity of the species and clarifying the status of the remaining paralectotypes. The species is currently treated as a synonym of Megalothoraca pterodontida, described by Hendel a year earlier, and the designation gives future revisers an unambiguous reference point when evaluating that synonymy. Similarly complex cases appear elsewhere in the collection, such as the syntype series of Richardia latibrachium, which spans specimens from Costa Rica and Mexico collected by different hands in 1907, and the syntypes of Richardia tephritina and Setellia punctigera, each documented with their co-type labels intact.

Tellingly, the survey found no type specimens attributable to any of the species Enderlein described in 1927, a silence that itself carries information about how the historical holdings were assembled and dispersed. The collection also preserves non-type specimens of species described by other authors, including Automola atomaria, Coilometopia trimaculata, Melanoloma decrepita and Melanoloma varians, and even two specimens of Melanoloma that cannot be assigned to a described species at all, identified only as Melanoloma sp. A full checklist of the Richardiidae species represented in the Warsaw collection accompanies the catalogue, providing a baseline for anyone planning revisions of genera such as Hemixantha, which alone comprises 20 known species and one subspecies, or Setellia, with 21 species and one subspecies.

The catalogue also sketches the life of the man behind the names. Günther Enderlein was born in Leipzig in 1872 and studied there and in Berlin, joining the Entomological Society Fauna of Leipzig as a student. He served as an assistant at the Zoological Museum in Berlin from 1900 to 1906, then worked as curator at the museum in Stettin until 1919, the period in which his Richardiidae work and the Stettin accession of tropical material intersected. Returning to Berlin, he curated the Zoological Museum of the University of Berlin until 1937, received the official title of professor in 1924, and died in Wentorf bei Hamburg at the age of 96. Across roughly 500 scientific papers he ranged far beyond flies, publishing on Hymenoptera, Psocoptera, Coleoptera and Hemiptera as well as numerous dipteran families, leaving type material scattered across collections that his successors are still tracing.

The Warsaw catalogue is not an isolated effort. It follows earlier documentation of Enderlein’s type material in the same institution, including works on the fly family Platystomatidae, on parasitic wasps of the family Ichneumonidae, and on the hymenopteran superfamilies Evanioidea and Stephanoidea, all published in the 1990s. Together these projects are turning a museum once defined by what it was thought to have lost into a proving ground for nomenclatural stability. For Richardiidae, a family whose ongoing revisions depend heavily on Neotropical type material, the newly photographed specimens from Santa Catharina, Ecuador, Colombia, Costa Rica, Mexico and Peru mean that the next generation of taxonomists can compare their specimens against definitive images and verified label data without waiting decades for a library loan. A century after Enderlein pinned his types in Stettin, the names he created finally have a fixed, visible, and publicly accessible foundation.

Subject of Research: Catalogue and documentation of Enderlein's Richardiidae type specimens preserved in the Museum and Institute of Zoology PAS in Warsaw

Article Title: Revisiting Enderlein's Richardiidae ( Diptera ): an illustrated catalogue of type specimens in the Museum and Institute of Zoology, PAS (Warsaw, Poland)

Article References: Schimrosczyk, D., Kamiński, M. J., & Barros, L. M. (2026). Revisiting Enderlein's Richardiidae (Diptera): an illustrated catalogue of type specimens in the Museum and Institute of Zoology, PAS (Warsaw, Poland). Evolutionary Systematics, 10(2), 345-357. https://doi.org/10.3897/evolsyst.10.206592

Image Credits: AI Generated

DOI: 10.3897/evolsyst.10.206592

Keywords: Richardiidae, Diptera, Günther Enderlein, type specimens, Stettin collection, Museum and Institute of Zoology PAS, taxonomy, nomenclature, lectotype designation, Neotropical flies, natural history collections, Entomology