Abstract
Within the pollinator family Syrphidae, Eumerus Meigen, 1822 is a diverse genus with over 70 species recorded in the Afrotropical Region. A new species is described here from Namibia and South Africa. Adults are small to medium size flies, with spur-like expansions in the metatarsomeres 2 and 3. DNA sequences of the Cytochrome c oxidase subunit I (COI) gene were obtained from Namibian specimens. This is only the second Eumerus species documented from Namibia, where it was recorded from The National Botanic Garden, Windhoek. The new species is compared with similar species such as Eumerus vestitus Bezzi, 1912, for which a lectotype is designated. In addition, a new and preliminary morphological concept of the Eumerus obliquus group is proposed and a key to its African species is provided.
References
Barkemeyer, W. (2002) Zur Syrphidenfauna der Kapverdischen Inseln (Diptera: Syrphidae). Mitteilungen des Internationalen Entomologischen Vereins e.v. Frankfurt am Main, 27, 9–28.
Bezzi, M. (1912) Ditteri raccolti da Leonardo Fea durante il suo viaggio nell’ Africa occidentale. Parte 1ª: Syrphidae. Annali del Museo civico di storia naturale di Genova, 45, 400–453.
Brunetti E. (1913) New and interesting Diptera from the eastern Himalayas. Records of the Indian Museum, 9, 255–277.
Brunetti, E. (1915) Notes on Oriental Syrphidae: with descriptions of new species. Part II. Records of the Indian Museum, 11, 201−256.
Curran, C.H. (1938) Records and descriptions of African Syrphidae.—I (Diptera). American Museum Novitates, 1009, 1−15.
Fabricius, J.C. (1805) Systema antliatorum secundum ordines, genera, species adiectis synonymis, locis, observationibus, descriptionibus. Reichard, Brunsvigae, 373 pp.
https://doi.org/10.5962/bhl.title.15806
Garcete-Barrett, B.R., Morales, M.N., Hauser, M., Smit, J.T., González, L., Ramírez De López, M.B., Arias, O., Adorno, M., Sormanti, G. & Mereles, A. (2020) New geographical records and key to the species of Eumerus Meigen, 1823 (Diptera, Syrphidae) introduced into the Americas and Hawaii. Revista Brazileira de Entomologia, 64 (1), 1–6.
https://doi.org/10.1590/1806-9665-rbent-2019-0016
International Commission on Zoological Nomenclature (1999) International Code of Zoological Nomenclature. 4th Edition. The International Trust for Zoological Nomenclature, London, 306 pp.
Kassebeer, C.F. (2000) Die Schwebfliegen (Diptera, Syrphidae) von La Réunion, mit Anmerkungen zur Fauna der Madagassis. Dipteron, 3 (1), 43–66.
Larson, B.M.H., Kevan, P.G. & Inouye, D.W. (2001) Flies and flowers: taxonomic diversity of anthophiles and pollinators. Canadian Entomologist, 133, 439–465.
https://doi.org/10.4039/Ent133439-4
Loew, H. (1857) Nachricht über syrische Dipteren. Verhandlungen des zoologisch-botanischen Vereins in Wien, 7, 79−86.
Lyneborg, L., Pape, T. & Thompson, F.C. (2015) New Afrotropical eumerine flower fly synonyms (Diptera: Syrphidae). Entomologist’s Monthly Magazine, 151, 117–124.
Marcos-García, M.A., Ricarte, A. & Estela, N. (2013) An updated hoverfly checklist (Diptera: Syrphidae) of the Mascarene Island of Réunion, France. Journal of the Entomological Research Society, 15, 59–68.
Meigen, J.W. (1822) Systematische Beschreibung der bekannten europäischen zweiflügeligen Insekten. Dritter Theil. Schulz-Wundermann, Hamm, x + 416 pp.
National Botanical Research Institute (2020) The National Botanic Garden. Available from: http://www.nbri.org.na/sections/botanic-garden (accessed 15 April 2020)
Ricarte, A., Marcos-García, M.A. & Rotheray, G.E. (2008) The early stages and life histories of three Eumerus and two Merodon species (Diptera: syrphidae) from the Mediterranean region. Entomologica Fennica, 19, 129–141.
https://doi.org/10.33338/ef.84424
Ricarte, A., Nedeljković, Z., Rotheray, G.E., Lyszkowski, R.M., Hancock, E.G., Watt, K., Hewitt, S.M., Horsfield, D. & Wilkinson, G. (2012) Syrphidae (Diptera) from the Greek island of Lesvos, with description of two new species. Zootaxa, 3175 (1), 1–23.
https://doi.org/10.11646/zootaxa.3175.1.1
Ricarte, A., Souba-Dols, G.J., Hauser, M. & Marcos-García, M.A. (2017) A review of the early stages and host plants of the genera Eumerus and Merodon (Diptera: Syrphidae), with new data on four species. PLoS ONE, 12 (12), e0189852.
https://doi.org/10.1371/journal.pone.0189852
Rotheray, G.E. & Gilbert, F.S. (2011) The Natural History of Hoverflies. Forrest Text, Cardigan, 334 pp.
Simon, C., Frati, F., Beckenbach, A., Crespi, B., Liu, H. & Flook, P. (1994) Evolution, weighting and phylogenetic utility of mitochondrial gene-sequences and a compilation of conserved polymerase chain-reaction primers. Annals of the Entomological Society of America, 87, 651–701.
https://doi.org/10.1093/aesa/87.6.651
Smit, J.T., van Harten, A. & Ketelaar, R. (2017) Order Diptera, family Syrphidae. The hoverflies of the Arabian Peninsula. In: van Harten, A. (Ed.), Arthropod fauna of the UAE. Vol. 6. Department of the President’s Affairs, Abu Dhabi, pp. 572–612.
Smith, K.G.V. & Vockeroth, J.R. (1980) Family Syrphidae. In: Crosskey, R.W. (Ed.), Catalogue of the Diptera of the Afrotropical Region. British Museum, London, pp. 488–510.
Speight, M.C.D. (2020) Species accounts of European Syrphidae, 2020. Syrph the Net, the database of European Syrphidae (Diptera). Syrph the Net publications, Dublin, 104, 1–314.
Souba-Dols, G.J., Ricarte A., Hauser, M., Speight, M. & Marcos-García, M.A. (2020) What do Eumerus larvae feed on? New immature stages of three species (Diptera: Syrphidae) breeding in different plants. Organisms Diversity & Evolution, 20, 267–284.
https://doi.org/10.1007/s13127-020-00437-0
Thompson, F.C. (1999) A key to the genera of the flower flies of the Neotropical Region including the descriptions of genera and species and a glossary of taxonomic terms. Contributions on Entomology, International, 3, 319–378.
Walker, F. (1859) Catalogue of the dipterous insects collected at Makessar in Celebes, by Mr. A. R. Wallace, with descriptions of new species. Journal of the proceedings of the Linnean Society, 3–4, 90–172.