Epeorus (Caucasiron) alpestris (Braasch, 1979)

Hrivniak, Ľubos, Sroka, Pavel, Bojkova, Jindriska & Godunko, Roman J., 2020, Identification guide to larvae of Caucasian Epeorus (Caucasiron) (Ephemeroptera, Heptageniidae), ZooKeys 986, pp. 1-53 : 1

Epeorus (Caucasiron) alpestris (Braasch, 1979) Figs 15 , 16 , 17

Iron alpestris Braasch, 1979

Epeorus (Iron) alpestris (Braasch, 1979); in Kluge (1988)

Epeorus (Caucasiron) alpestris (Braasch, 1979); in Kluge (1997b)

Type locality.

Russia, The Karachay-Cherkess Republic, western Greater Caucasus, Teberda (Glacier Alibek - stream, 1800-1900 m a.s.l.).

Distribution.

Georgia, south-western Russia. Species endemic to the Greater Caucasus (Fig. 15 ).

Habitat.

Larvae inhabit small streams and rivers at middle and high altitude in the western and central Greater Caucasus. Altitudinal range of sampling sites 570-2580 m a.s.l (Fig. 15 ). Most frequently found at altitudes above 1200 m a.s.l. Often syntopic with E. (C.) soldani and at higher altitude with E. (C.) sinitshenkovae .

Main morphological diagnostics of larvae.

(i) abdominal terga V-VII with narrow stripe-like medial macula; widened on terga VIII-IX (Fig. 16G, H , arrows); (ii) abdominal sterna II-VI with rounded medial macula (Fig. 16B, I ); (iii) femora without medial hypodermal spot (Fig. 16F ); (iv) tergum X without postero-lateral projections (Fig. 17L ); (v) gill plates III with well-developed projection (Fig. 17G ); (vi) setae on abdominal terga hair-like (Fig. 17E ); (vii) dorsal surface of labrum with sparse hair-like setae (Fig. 17A ); (viii) gill plates VII (in natural position of ventral view) wide (Figs 16J, K , 17H-K ).

Remarks.

Taxonomy. This species was described based on the male imago and larva from western Greater Caucasus ( Braasch 1979). The type series is currently deposited in SMNS. Imagines and larvae were associated based on the coloration of abdomen. Female imago not described.

Figures

Figure 15. Geographical (left) and vertical (right) distribution of Epeorus (Caucasiron) alpestris.

Figure 16. Epeorus (Caucasiron) alpestris, larva: A habitus in dorsal view B habitus in ventral view C habitus in lateral view D head of male in dorsal view E head of female in dorsal view F middle leg in dorsal view G, H abdominal terga (arrows point on widened medial maculae) I abdominal sterna II-VI J, K gills VII (in natural position from ventral view).

Figure 17. Epeorus (Caucasiron) alpestris, larva: A labrum (left half in dorsal view right half in ventral view) B incisors of left mandible C incisors of right mandible D setae on dorsal surface of femora E surface and posterior margin of abdominal tergum VII F gill I G gill III H gill VII (flattened on slide) I-K gill VII (in natural position from ventral view) variability in shape L abdominal segments VIII-X in lateral view M sternum IX of female with observed variability.