Palingenia fuliginosa (Georgi, 1802)

Martynov, Alexander V., 2018, New records of some rare mayflies (Insecta, Ephemeroptera) from Ukraine, Ecologica Montenegrina 16, pp. 48-57 : 49-52

Palingenia fuliginosa (Georgi, 1802)

There are three species of the genus Palingenia Albarda, 1888 in the check list of Ukrainian mayflies (Godunko & Kłonowska- Olejnik 2003). Palingenia longicauda (Oliver, 1791) has not been registered in Ukraine since the thirties of the XX century ( Soldan et al. 2009). Registration of P. sublongilobata Tshernova, 1949 in Ukraine needed the confirmation, and Palingenia fuliginosa was only suggested for Ukraine (Godunko & Kłonowska- Olejnik 2003; Prokopov & Godunko 2007).

Generally confirmed distribution of P. fuliginosa falls within Iran, Caucasus and Slovak Republic ( Tshernova 1949; Demoulin 1965; Soldán 1978). Demoulin (1965) recorded P. fuliginosa for Crimea basing on one female imago from Kertch Peninsula. It was supposed that species do not develop in Crimea, and the caught specimen was carried by wind from Krasnodar Krai ( Russian Federation) ( Prokopov & Godunko 2007). The records of this species from the Salgir and Angara Rivers at Crimea by Kiseleva & Yezernitskiy (1985) was subjected to great doubt and consequently the species was removed from check list of mayflies of Crimea ( Prokopov & Godunko 2007). Thereby, up to now there are no facts confirming the development of this species within Ukraine.

We found P. fuliginosa in potamal zone of the Horyn’ and Styr Rivers within Rivne Region ( Figs 3, 4 , 14, 15 ). Larvae of different ages and winged stages were collected ( Figs 1, 2 , 5 ); this confirms the fact of development of the species within Ukraine. Moreover, these records extend the known distribution of the species towards North.

Habitat: In both rivers larvae of P. fuliginosa live under the similar conditions. All larvae were collected from their burrows in different substrates. Most typical substrates were the clay ( Fig. 5 ) and dense deposits of sand, and we also collected some larvae from burrows made in poor bog iron ore with sandstone impurities ( Fig. 6 ). Additionally we recorded that the larvae of last instars can rote the burrows through the wood when it is deposed in the main substrate ( Fig. 7 ).

Current velocity in collecting sites ranged from 0.1 to 0.3 m /s. The inhabited holes of P. fuliginosa were registered at depth from 0.2 to 1.7 m (max depth of the rivers in the sampling places was about 3 m). The additional parameters of waterbodies in collecting places measured during the sampling were: water temperature 23–29°C, water hardness 259–270 ppm, pH 8.6–8.7.

Material: Ukraine, Rivne Region: 11 larvae, vicinity of Zbuzh village, Horyn’ River , 50.990300, 26.320683, h – 154 m a.s.l., Martynov A. V. leg., 7.07.2017 – IN Riv 2 Palful /1–2 ; 20 larvae, 14 subimagoes, ibid, Dauletkulov S. leg., 10– 25.06.2017 – IN Riv 6 Palful /1–6 ; 10 larvae, vicinity of Stara Rafalivka village, Styr River , 51.378866, 25.863339, h – 156 m a.s.l., Martynov A. V. leg., 2.08.2017 – IN Riv 7 Palful .

Threats and recommendations for conservation: Palingenia fuliginosa is a highly stenobiotic species that prefers only the oxygenated unpolluted waterbodies. As the result, species inhabits only a few rare types of microhabitats in some middle-sized rives within Ukraine. We suppose that at the present time there are several main factors influencing the abundance of the species in discovered habitats except of the moderate pollution. The first factor is the significant decrease of the average water level in Horyn’ and Styr Rivers in last few years. Because of this decrease the main part of the suitable microhabitats appeared to be located above the water during most of a year. Many old burrows made by larvae of P. fuliginosa were registered above the water level. Now only a small area with suitable microhabitats was preserved in these rivers. Larvae of the species can not inhabit bottom and neighboring microhabitats because of their siltation.

The second factor is the human factor. It is very popular among the people of Rivne Region to collect the larvae and winged stages (imagoes and subimagoes) of P. fuliginosa for fishing. We consider this as a significant threat. People use special hand device that scrapes the substrate to collect the larvae ( Fig. 8 ). Because of this the large areas of rare suitable habitats of the species were destroyed. Also people collect the newly emerged winged stages (mainly subimagoes) with the light traps. Before the water level decrease in the Horyn’ and Styr Rivers some people collected for the sale up to one hundred (!) kilograms of larvae and up to 5–6 hundreds (!) kilograms of winged stages (mainly subimagoes). Obviously the caught subimagoes could not participate in the reproduction. Because of significant restriction of the species’ distribution in the region, small area and number of suitable microhabitats and big volume of collected mayflies, we consider the human activity as one of the significant threats for the discovered (!) populations of P. fuliginosa .

Thus, we suppose that this species deserves to be included in the Red Data Book of Ukraine. Detailed investigation (also genetic affinity to other populations) of discovered populations of P. fuliginosa continues.

Figures

Figures 1–4. Larva and subimago of Palingenia fuliginosa (Georgi, 1802) and its habitat: 1. – total view of larva, scale bar 10 mm; 2. – total view of subimago, male, scale bar 10 mm; 3. – Horyn’ River, vicinity of Zbuzh village (July 2017); 4. – microhabitats most preferred by P. fuliginosa larvae on Horyn’ River (July 2017).

Figures 14–18. New collection sites of the investigated species within Ukraine: 14. – map showing new sites (red circles – Palingenia fuliginosa (Georgi, 1802); yellow circles – Isonychia ignota (Walker, 1853); green circle – Baetopus tenellus (Albarda, 1878); blue circles – Brachycercus harrisella Curtis, 1834; red quadrates – Siphlonurus aestivalis Eaton, 1903; yellow quadrate – Metreletus balcanicus (Ulmer, 1920)); 15. – Styr River, (vicinity of Stara Rafalivka village, July 2017); 16. – Stvyga River (vicinity of Poznan’ village, July 2017); 17. – bay of Desna River (vicinity of Prydesnyans’ke village, May 2017); 18. – Salva River (territory of Bukove village, May 2017).

Figures 5–8. Palingenia fuliginosa (Georgi, 1802), larval burrows and equipment for collecting the larvae: 5. – larva in the burrow, scale bar 50 mm; 6. – burrows in poor bog iron ore with sandstone impurities, scale bar 50 mm; 7. – burrows crossing the wood, scale bar 50 mm; 8. – equipment used by fishermen and dealers for collecting the larvae, scale bar 50 mm.