Epeolus sibiricus Radoszkowski, 1887

Astafurova, Yulia V. & Proshchalykin, Maxim Yu., 2021, Review of the Epeolus tarsalis species group (Hymenoptera: Apidae, Epeolus Latreille, 1802), with description of a new species, Zootaxa 5006 (1), pp. 26-36 : 33-34

Notes on Epeolus sibiricus Radoszkowski

Taxonomical status of E. sibiricus Radoszkowski described in both sexes from Vladivostok (Primorskiy Territory, Russia) remains unresolved. Bischoff (1930), Pittioni (1947), and van Lith (1956) considered this name as valid. However, van Lith (1956) noted that E. sibiricus is presumably not more than a subspecies of E. tarsalis . Quest (2009) listed E. sibiricus as a valid species and recorded it from Primorskiy Territory based on several specimens determined by M. Schwarz (Ansfelden, Austria). Warncke in his notes (unpublished, P. Bogusch, personal communication) suggested the synonymy of E. sibiricus with E. tarsalis . Bogusch and Hadrava (2018) listed E. sibiricus as a synonym of E. tarsalis , but without comments and indicated that types were not examined. In the “Annotated Catalogue of the Hymenoptera of Russia ” ( Levchenko et al. 2017) this name was omitted. The re-examination of syntypes is required to clarify this synonymy and until this action we treat E. sibiricus as a possible synonym of E. tarsalis . The type materials of E. sibiricus were deposited in Museum für Naturkunde, Berlin ( Germany), but they were borrowed by F. Gusenleitner in 1998 and probably are still in Oberösterreichisches Landesmuseum, Biologiezentrum, Linz ( Austria).

According to Pittoni (1947) E. sibiricus differs from E. tarsalis by the red pronotal lobe in males, the entirely red mesepisternum in females and the reduction lateral fasciae on T2 and T3. Among specimens of E. tarsalis examined by us from Siberia and Far East, there are no males with red pronotal lobes and there are no females with red mesepisternum. Also, there are no females with lateral fascia on T2 reduced to two spots as in E. sibiricus . It should be noted that such red coloration of the mesepisternum and reduction of the tergal lateral fascia are typical for female specimens of E. melectiformis collected in the Primorsky Territory ( Figs 9, 11 ), and which are relatively common there. So, the female syntype (s) of E. sibiricus may belong to E. melectiformis . However, the male of E. tarsalis (?= sibiricus ) is well distinguished from E. melectiformis by lacking long setae just before the posterior margin of the last sterna. This important feature was mentioned by Pittoni (1947) in diagnosis of the E. tarsalis species group, so the male syntype (s) of E. sibiricus cannot be E. melectiformis . Quest (2009) recorded several specimens of E. sibiricus in the Lazovsky Nature Reserve (Primorsky Territory), but did not list E. tarsalis and E. melectiformis . In our material, we only have a male from the Lazovsky Nature Reserve belonging to E. tarsalis .

Figures

FIGURES 8–11. Epeolus tarsalis Morawitz, female (8—from Jewish Autonomous Prov.; 10—from Irkutsk Prov.), E. melectiformis Yasumatsu (9, 11—both from Primorsky Terr.), lateral view. Scale bars: 1.0 mm.