Finally, several months delayed is a post about my recent field work in South Africa and Namibia that took place in September 2017.
My field work took me from Cape Town, South Africa to Windhoek, Namibia – a distance of some 1,500 km (930 miles) if you drive straight, which I didn't. I had planned to visit several habitats in the Western and Northern Cape of South Africa and Karas in Namibia to collect spring-active assassin flies (Asilidae), mydas flies (Mydidae), and other Asiloidea and pollinators such as Nemestrinidae (tangle-veined flies) for a project on the evolutionary relationships of Asiloidea and Nemestrinoidea based on morphological data. Because of a severe drought in this part of southern Africa, my collecting wasn't very successful with a few exceptional collecting localities though. Further north, I was planning to visit the Namib Desert again and in particular the Gobabeb Research & Training Centre (www.gobabebtrc.org). Once I arrived in the true desert, collecting was wonderful as the flies occurring here are not reliant on winter rainfall such as further south.
I would like to thank the government agencies in the Western Cape (CapeNature), Northern Cape (Permit Section), and Namibia (Ministry of Environment and Tourism) for issuing collecting permits. Furthermore, the staff at the Gobabeb Research & Training Centre was very helpful as always and in particular Ritha Kapitango, Leena Kapulwa, Angi Storbeck, and Theo Wassenaar assisted in many ways.
Here are some of the habitats I visited:
1. Rocherpan Nature Reserve (Western Cape, South Africa) where Acnephalomyia dorsalis (Macquart, 1838), Haroldia trivialis (Oldroyd, 1974), Hypenetes sp., Corymyia melas Londt, 1994, and Neolophonotus sp. (Asilidae), Neotabuda lanigera Lyneborg, 1980 (Therevidae, stiletto flies), Corsomyza sp., Megapalpus capensis Hesse, 1938, and Tomomyza sp. (Bombyliidae, bee flies) were collected. Haroldia trivialis (see image below) was collected in abundance perching on the sand of the coastal dune (foreground) as was Corymyia melas, but the other species were collected near the pan (in the distance).
2–3. Gifberg Pass (Western Cape, South Africa) where Neolophonotus sp., Rhipidocephala sp., and Damalis conspicua Curran, 1934 (Asilidae), Neotabuda sp. (Therevidae), and Apatomyza sp. (Bombyliidae) were collected. This fynbos habitat was amazing (even on a cloudy day) and the Rhipidocephala species (see images below) surprised me by perching mostly on little rocks and not on vegetation.
4. A special treat was driving through the /Ai-/Ais Richtersveld Transfrontier Park (Karas, Namibia) along the "mighty" Gariep or Orange River, which is the largest river in western South Africa. In the adjacent sandy habitat, I was able to collect Stichopogon punctum Loew, 1851 (Asilidae) and Orthactia sp. (Therevidae).
5. A rocky hillside at Klein-Aus Vista (Karas, Namibia) where Neolophonotus sp. and Anasillomos chrysopos Londt, 1983 (Asilidae) were collected. This is the northern-most area where the winter rainfall should bring out spring flowers, but the last proper rain fell here in 2014.
6. For the 2nd time I visited this site in the Namib Desert at the eastern-most edge of the Namib sand sea on the C14 north of Solitaire (Khomas, Namibia) where Anypodetus sp., Microphontes gaiophanes Markee & Dikow, 2018, and Stichopogon hermanni Bezzi, 1910 (Asilidae) and Orthactia sp. (Therevidae) were collected. I have never seen Microphontes (see images below) before and the collected specimens represented an undescribed species for which I was able to record some peculiar flight behavior (see publication at 10.3897/AfrInvertebr.59.30684). The Anypodetus species likewise appears to be undescribed.
7. The Gobabeb Research & Training Centre (Erongo, Namibia) is an amazing place to visit in the heart of the Namib Desert. This time, I was unable to collect any assassin flies on the high dunes (as shown here), which are situated west and south of the research station (visible in the distance to the right of the wooded dry Kuiseb riverbed). I was able to collect Xeramoeba sp. (Bombylliidae) on these high dunes though.
8. The edge of the high dunes adjacent to the wooded dry Kuiseb riverbed at Gobabeb proofed very interesting though where Sporadothrix sp. and Prytanomyia kochi (Lindner, 1973) (Asilidae, see images below) as well as Parectyphus namibiensis Hesse, 1972 and an undescribed genus and species of Mydidae (see image below) were collected.
9. Just as in my previous visit to Gobabeb, Orthactia gobabensis Lyneborg, 1988 (Therevidae), Trichardis picta Hermann, 1906 (see image below), and Stichopogon punctum Loew, 1851 (Asilidae) were collected in the dry Kuiseb riverbed.
Here are some of the photographs of flies in nature taken with an Olympus OM-D EM-5 Mark II and a f/2.8 60 mm macro-lens (= 120 mm focal length in 35 mm photography):
10. A female stiletto fly of Caenophthalmus gracilis Lyneborg, 1976 (ID via iNaturalist Shaun Winterton, Therevidae: Therevinae) ovipositing at Cape Columbine Nature Reserve (Western Cape, South Africa). See iNaturalist observation: 63854583.
11. Acnephalomyia dorsalis (Macquart, 1838) (Asilidae) perching on sand at Rocherpan Nature Reserve (Western Cape, South Africa). See iNaturalist observation: 63854661.
12. Female Haroldia trivialis (Oldroyd, 1974) (Asilidae) perching on sand dune at Rocherpan Nature Reserve (Western Cape, South Africa). See iNaturalist observation: 63855130.
13. A male Neotabuda lanigera Lyneborg, 1980 stiletto fly (Id via iNaturalist Shaun Winterton, Therevidae) resting on sand at Rocherpan Nature Reserve (Western Cape, South Africa). See iNaturalist observation: 63854969.
14. Male Neolophonotus sp. (Asilidae) feeding on an aphid on a rock at Gifberg Pass (Western Cape, South Africa). See iNaturalist observation: 63855347.
15–16. Rhipidocephala sp. (Asilidae) perching on rock and my collecting net at Gifberg Pass (Western Cape, South Africa). See iNaturalist observation: 63855466.
17. Female Stichopogon punctum (Asilidae) feeding on a hemipteran at Gariep (Orange) River in /Ai-/Ais Richtersveld Transfrontier Park (Karas, Namibia). See iNaturalist observation: 63855586.
18–19. Microphontes gaiophanes Markee & Dikow, 2018 (Asilidae) perching on sand dune (18, male) and dry twigs (19, female) at Namib-Naukluft National Park near Solitaire (Erongo, Namibia). See iNaturalist observations: 63855855 + 63855886.
20–21. Female Sporadothrix sp. (Asilidae) perching on sand dune (20) and ovipositing in sand (21) at Gobabeb in the Namib-Naukluft National Park (Erongo, Namibia). See iNaturalist observation: 63856014.
22. Female Trichardis picta (Asilidae) perching on sand in dry Kuiseb riverbed at Gobabeb in the Namib-Naukluft National Park (Erongo, Namibia).
23. Female Prytanomyia kochi (Asilidae) perching on dung on small sand dune at Gobabeb in the Namib-Naukluft National Park (Erongo, Namibia). See iNaturalist observation: 63856269.
24. Female mydas fly of an undescribed species and genus (Mydidae) resting on dry leave on small sand dune at Gobabeb in the Namib-Naukluft National Park (Erongo, Namibia). This species was one of the target taxa on my list to collect and so I was extremely happy to collect and photograph it in nature.
Some impressions of southern Africa:
25. Whenever I can, I stop by botanical gardens and Kirstenbosch National Botanical Garden (www.sanbi.org/gardens/kirstenbosch) in Cape Town is one of the world's most beautiful gardens.
26. I also visited the National Botanic Garden (www.nbri.org.na/sections/botanic-garden) in Windhoek.
The flower diversity in western South Africa always amazes me and here are just some impressions.
27. Baboon root (genus Babiana, Iridaceae) at Cape Columbine Nature Reserve (Western Cape, South Africa). See iNaturalist observation: 63856269.
28. Capebells (genus Wahlenbergia, Campanulaceae, ID via iNaturalist) at Gifbeg Pass (Western Cape, South Africa). See iNaturalist observation: 63855308.
29. King Kalkoentjie (Gladiolus alatus, Iridaceae, ID via iNaturalist) at Gifbeg Pass (Western Cape, South Africa). See iNaturalist observation: 63855241.
Namibia is a place of huge distances between towns.
30. Getting ready for the drive through /Ai-/Ais Richtersveld Transfrontier Park along Gariep (Orange) River (Karas, Namibia).
31. Near Rosh Pinah (Karas, Namibia).
32. Near Aus (Karas, Namibia).
Other wildlife:
33. Four-striped grass mouse (Rhabdomys pumilio (Sparman, 1784)) at Rocherpan Nature Reserve (Western Cape, South Africa). ID by Molly McDonough.
34. Friendly tortoise at Rocherpan Nature Reserve (Western Cape, South Africa).
35. Chacma baboons (Papio ursinus Kerr, 1792) in /Ai-/Ais Richtersveld Transfrontier Park (Karas, Namibia) watching what I am doing with my collecting net.
36. The ever so beautiful Kokerboom (Aloidendron dichotomum (Masson) Klopper & Gideon F.Sm.) just outside /Ai-/Ais Richtersveld Transfrontier Park (Karas, Namibia).
37. Tree Locust (Anacridium moestum (Serville, 1838), Orthoptera: Acrididae) hiding among dry vegetation at Klein-Aus Vista (Karas, Namibia). See iNaturalist observation: 63855760.
38. Hartmann's Mountain Zebra (Equus zebra hartmannae (Matschie, 1898)) at Namib-Naukluft National Park near Solitaire (Erongo, Namibia).
39. Blister beetle (Meloidae) on dune plant at Namib-Naukluft National Park near Solitaire (Erongo, Namibia).
40. Thread-winged lacewing Nemopterella sp. (Nemopteridae, ID via iNaturalist) at Namib-Naukluft National Park near Solitaire (Erongo, Namibia). This thread-winged lacewing was very pale and I assume it had recently emerged from the pupa and had not fully hardened/colored. See iNaturalist observation: 63855936.
41. Dune lark (Calendulauda erythrochlamys (Strickland, 1853)) on high dunes at Gobabeb, Namibia-Naukluft National Park (Erongo, Namibia) – Namibia's only true endemic bird species. See iNaturalist observation: 63856209.
42. My companions – Olympus and collecting net.
43. Cheese cake (Quarkkuchen) is always good and the German heritage can still be found in Namibia.
Posted by Torsten Dikow.
Updates: 2018-03-08 - Molly McDonough kindly identified the grass mouse photograph.
2018-03-12: Several species identifications were added.
2021-04-13: IDs and links to iNaturalist observations added.
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