Epeorella borneonia Ulmer, 1939

Sartori, Michel, 2014, On the validity of Epeorella Ulmer, 1939 (Ephemeroptera, Heptageniidae) with general considerations on the Heptageniidae of the Sunda Islands, ZooKeys 445, pp. 97-106 : 98-99

Taxon classification Animalia Ephemeroptera Heptageniidae

Epeorella borneonia Ulmer, 1939

Epeorella borneonia : Ulmer 1939: 579 (male and female imago).

Epeorus borneonia : Wang and McCafferty 2004: 21.

Material examined.

One male imago, one female imago, one female subimago, all bearing the following labels: 1) Type [typewriting on red label], 2) Borneo, Nanga Serawei, 12-18.11.1924 3) Sammelreise Prof. Dr. H. Winckler, ded. 1924-1925 4) Z.M.H. Hamburg 5) G. Ulmer det. 1942 Vers. 13.9.1927. This last label is confusing, and according to Prof. H. Strümpel (in litt.) it is a probable mistake.

The male imago was wrongly mentioned as holotype by Weidner (1962). This terminology cannot be accepted because the “holotype” has not been designated by Ulmer and cannot be ascertained by the presence of a single specimen (see also Recommendation 73F. Avoidance of assumption of holotype, ICZN 1999).

The male imago is accordingly designated as LECTOTYPE of the species Epeorella borneonia by present designation.

The three specimens have been adequately described by Ulmer (1939). Only significant morphological characters are mentioned here.

Male imago.

Anterior margin of the head not protruding anteriorly (Fig. 1); median depression of mesothoracic furcasternum subparallel, not convergent anteriorly (Fig. 3); mesonotum with a transverse suture (Fig. 2); styliger fig strongly convex, penis lobes minute, rounded and closely tight together (Fig. 4), without apparent sclerites or titillators [a complete analysis of the genitalia will be presented later with the help of non-invasive techniques].

Female imago.

Abdominal patterns similar to the male. Extracted eggs from the rehydrated specimen were unfortunately not in a satisfactory state for chorionic structure examination through SEM.

Female subimago.

Similar to the female, except abdominal terga VI–VIII ( IV–V to a lesser extent) present the remains of a longitudinal ridge (Figs 5-6).