The Mayfly Newsletter Volume 23 Issue 1 Article 1 7-15-2020 The Mayfly Newsletter Donna Giberson [email protected] Follow this and additional works at: https://dc.swosu.edu/mayfly Part of the Biology Commons, Entomology Commons, Systems Biology Commons, and the Zoology Commons Recommended Citation Giberson, Donna (2020) "The Mayfly Newsletter," The Mayfly Newsletter: Vol. 23 : Iss. 1 , Article 1. Available at: https://dc.swosu.edu/mayfly/vol23/iss1/1 This Article is brought to you for free and open access by the Newsletters at SWOSU Digital Commons. It has been accepted for inclusion in The Mayfly Newsletter by an authorized editor of SWOSU Digital Commons. An ADA compliant document is available upon request. For more information, please contact [email protected]. The Mayfly Newsletter Vol. 23(1) June 2020 The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera In this issue Tales from the field: Tales from the field 1. Siphlonurus marhsalli in tributaries of the Buffalo River 1. Siphlonurus marshalli in the Dave Funk Buffalo River; Dave Funk...........1 Stroud Water Research Center, Avondale, Pennsylvania, USA 2. Mayfly collecting adventures in the unexplored Angolan wilds; I was able to sneak in a little vacation/collect- Helen Barber-James..................2 ing trip to the Arkansas Ozarks the last two weeks of March, just before things really shut Reports and notices: down on account of the corona virus. While 2021 XVITH International Con- searching for Ameletus in some tiny tributar- ference on Ephemeroptera and ies of the Buffalo River, I found bucketloads XXITH International Symposium of Siphlonurus marshalli Traver 1934. These on Plecoptera...........................6 streams are presumably seasonally intermit- tent, and fishless (due to their isolation from Zootaxa Ephemeroptera Editors’ more permanent water bodies by tall water- annual summary and acknowl- falls). I brought nymphs home to rear and edgements (2019); L. Jacobus, M. include a photo of an adult male here. Also in- Siphlonurus marshalli Traver 1934 Sartori, F. Salles, and P. Suter.....7 cluded, photos of one of the streams in which Funk D. I found them, and a typical waterfall at the IUCN Mayfly Report; Craig lower end of the reach. If these are like other MacAdam................................8 Siphlonurus I have worked with, their eggs will not hatch until late fall or winter. I hope to Report from SWOSU Digital Com- set up some experiments to test whether the mons; Phillip Fitzsimmons..........9 eggs can withstand desiccation in late sum- VI Symposium of Neotropical mer, which I Aquatic Insects.......................10 expect they may have New Book: Stenacron Mayflies..10 to endure in these How to donate to the streams. International Permanent These Committee on Ephemeroptera streams run Conferences...........................11 mostly on 2019 Mayfly Bibliography .........12 bedrock and so presum- Print copies of many issues still ably have no available................................19 hyporheic zone which Submissions to the Mayfly might provide Newsletter .............................19 a wet refuge. D. Funk D. Tributary to Buffalo River near Ponca D. Funk D. Hoskins tributary The Mayfly Newsletter is published (on-line) at https://dc.swosu.edu/mayfly/ (see link on Ephemeroptera Galactica: http://www.ephemeroptera-galactica.com/) contact: Donna J. Giberson, Editor email [email protected] Masthead image: Hexagenia sp. Andy Usher (Indiana University, Purdue University, Indianapolis) The Mayfly Newsletter 2 2. Mayfly collecting adventures in the unexplored Angolan wilds with the National Geographic Okavango Wilderness Project (NGOWP) Helen M. Barber-James Department of Freshwater Invertebrates, Albany Museum, Somerset Street, Makhanda (Grahamstown) 6139, South Africa. Department of Zoology and Entomology, Rhodes University, Makhanda (Grahamstown) 6140, South Africa. National Geographic Okavango Wilderness Project, Wild Bird Trust, South Africa. How does one describe the atmosphere of incredible peace that seeps into one’s soul in the wilds of Angola? Just me and the open bush, with a myriad different wild bog-orchids blooming to tempt me further and further from the camp to see yet another gorgeous bloom. Walking along the banks of the remote rivers, so peaceful now, yet witness to one of the most horrible civil wars in Africa, it’s hard to imagine that this beautiful place was ravaged by 27 years of civil war between 1975 and 2002. Yet the rusting armoured tanks (Figure 1) and trucks along the roadsides, missiles, and the occasional pock-marked ruins of once fine buildings are a stark reminder of darker times. Uncleared landmines are still a danger to anyone walking around in the bush in many parts of the country. The HALO Trust, an international H.M.Barber-James organisation committed to help countries recover Figure 1. An old army tank, once an emblem of fear, now a place of social after conflict by removing landmines and other gathering. post-war hazards, has an Angolan team which advises the NGOWP exploration and research teams which areas are safe and which are no-go areas. They have cleared areas so that many of the rural villages can once more be occupied safely, but the red and white markings painted on the trees are a sinister reminder not to go beyond that point. I was privileged to be part of the scientific team exploring the diversity of flora and fauna in the beautiful, remote Angolan highlands (Figure 2), with my freshwater invertebrate research team present on four expeditions between 2016-2019. Even the journey to reach the sites was an adventure (Figure 3). The unusual source lakes in the headwater valleys, grass and sedge-banked, flanked with stretches of miombo woodland on the higher ground beyond, are unique to this region. The lakes, high up in the plateau of the catchment, despite their name “source lake”, are not actually the source of the rivers. Typically, a deep, crystal-clear spring, fed by the surrounding marshland and peatbogs, gurgles into the head of a lake (Figure 4), with a larger stream forming at the outlet of the lake. These source lakes are not large, most are less than a square kilometre in area, but are very beautiful. However, they are remarkably difficult to access, surrounded by deep, marshy wetland and peat Figure 2. Map of Africa showing Angola in green, with the broader study site area, the so called “water tower’’ region indicated by red-dotted ellipse. The bogs, which have been measured to a depth of Okavango Delta is dependent on water from this region, as is Lake Kariba five meters (National Geographic, 2016). The (Zimbabwe) and Cahora Bassa (Mozambique), both large impoundments on presence of peat is very important as it forms a the Zambezi River (see red-dotted ellipses). seepage system, slowly releasing water the year Volume 23(1) June 2020 The Mayfly Newsletter 3 Figure 3. Travelling to one of our camp sites, showing slip- pery, muddy roads and a typical wooden bridge at river cross- ings, this one at Cuemba River. H.M.Barber-James H.M.Barber-James H.M.Barber-James Figure 4. Spring flowing into the upper end of Cuanavale source Figure 5. View across Cuanavale source lake, showing our camp lake. site in the distance. round, even in the dry season. The stream exiting a lake can soon become quite a big river, in turn feeding into other larger swiftly flowing sand-bed rivers. The underlying geology is composed of ancient Kalahari sands, and the bottoms of the lakes and rivers is sandy, with very few areas of rock. The lakes are often covered with water lilies, Nymphaea nouchali var. caerulea (Figures 5 and 6), which have immense tubers, delicious to eat when cooked properly (Figure 6). These tubers seem to provide habitat for some of the burrowing mayflies in the area (Polymitarcyidae,Povilla sp.), and hours of searching produced a few tiny larvae; seemingly it was the wrong season for the adults as none were collected at the November light traps. One of the challenges of working there is that the lakes and rivers are inhabited by crocodiles, which rather limits the freedom of collecting within the lake and in the deeper pools in the rivers. The river beds are rich in aquatic macrophytes which harbour a variety of interesting mayfly species, although that being said, the area has a rather low diversity of species. A point of great interest, noted in particular at the Cuananvale source lake in November 2019, was the minute size of several of the adult aquatic insects collected, including a tiny dragonfly, a minuscule caenid mayfly, and an even smaller than usual hydroptilid caddis, all of which are species new to science. We speculate that H.M.Barber-James the small size of these organisms may be due to the low nutrients in these Figure 6. Water lily stem being harvested, leached, sandy environments, which possibly also may account for the low looking for Povilla larvae, but later eaten for diversity. The diversity increases considerably in areas with hard substrate. dinner. Assisted by Mr Water, our expert ma- koro poler. Volume 23(1) June 2020 The Mayfly Newsletter 4 There is very little rocky habitat, and the occasional waterfall provides a very different fauna to the sandy bottomed lakes and rivers, as would be expected. The magnificent waterfall at the Luanginga River (Figure 7), for example, produced nymphs of the enormous Elassoneuria grandis (Oligoneuriidae), while in quite backwater pools nearby, larvae of the detritus-loving Machadorythus (Machadorythidae) (Figure 8) lurked in the shallows, their strange stalk-like eyes peering above the fine detrital particles covering the rocks. Machadorythus maculatus was the only species documented from Angola before the start of these NGOWP expeditions, described in 1959 by the Belgian, Georges Demoulin (Demoulin, 1959).