Trachusa balcanica , Kasparek, Max, 2018

Kasparek, Max, 2018, Taxonomic revision proves Trachusapubescens (Morawitz, 1872) sensu lato to be a complex of allopatric and sympatric species in South-Eastern Europe and Western Asia (Hymenoptera, Apoidea, Anth, ZooKeys 764, pp. 111-144: 111

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Trachusa balcanica

sp. n.

Trachusa balcanica  sp. n. Figs 11, 12, 13, 14, 15


Holotype: Male. BULGARIA: Sandanski (Blagoevgrad Province, south-western Bulgaria), June 1972, K. Poláček leg. (cMS). - Paratype (1): BULGARIA: male, same location as holotype, 26.-31.5.1967, Kocourek leg. (cMS).

Further material examined (21): BULGARIA: 1♀, Sandanski, 26.-31.5.1967 (cMS); 1♀, ibid., 1.-8.06.1967 (cMS). GREECE: 1♀ 1♂, 35 km NE Kalambaka, 15.05.2005, J. Halada / M. Kadlecová leg. (cMS); 1♂, Hellas, Kastoria, Aposkepos (850 m), 06.vii.1967, J. Reinig leg. (SMF); 1♂, Koupaki (38°30'N, 22°01'E), northwestern part of Phocis, central Greece, 21.05.1990, H. Malicky leg. (cMS). HUNGARY: 2♂, Hungary, E. Frivaldski leg. (ZMB); 1♂, South Hungary, ex coll. Schmiedeknecht (ZMB); 1♀ 1♂, central Hungary, ex coll. Alfken (ZMB); 1♀ 1♂, Budapest, A. Mocsáry leg. (ZMB). MACEDONIA (Former Yugoslav Republic): 2♂, Prilep, 01.06.1968, K. Warncke leg. (OLL). SERBIA: 1♀, 1♂, Deliblat, 23.07.1886, H. Friese leg. (SMF); 1♀, 3♂, same data (ZMB).

Material not examined: The Hungarian Natural History Museum holds 11 female and 27 male specimens labelled as "Trachusa pubescens" which according to the collection localities can most probably be assigned to T. balcanica  : Deliblat (Serbia), Budapest (Hungary), Grebenac (Serbia), Kecskemét (Hungary), Halas [=Kiskunhalas] (Hungary), Peszér [= Kunpeszér] (Hungary), Kecel (Hungary), and "Hungariae centralis". Some males have no locality label at all.

Differential diagnosis.

The smallest species of the T. pubescens  complex (mostly 13-16 mm versus mostly 16-20 mm). Males are separated from T. pubescens  , the only other European species of the complex, by the conspicuously emarginate apex of the clypeus (almost straight in T. pubescens  s. str.), with 8-11 small tubercles in the emargination (indistinguishable or hardly distinguishable tubercles in T. pubescens  ). Trachusa balcanica  sp. n. shares this feature with the remaining members of the species group.

Both sexes have a yellow stripe on vertex, sometimes attenuated in the middle or reduced to small remnants. This stripe is absent in T. pubescens  s. str. which also occurs on the Balkans. Yellow maculation in the genal area in T. balcanica  sp. n. is usually confined to the upper half (usually one-third); in only two out of 23 males, the genal maculation extends slightly on to the lower half, but never reaches the lower end of the eye as in T. hakkariensis  sp. n. and T. maxima  , or extends over most of the genal area as in T. pubescens  and T. verhoeffi  . In eight females examined, the yellow maculation extends in three cases slightly onto the lower half but is confined to the upper half in the other cases.

T6 of males has a broad, usually rounded median projection; apex rounded or at most truncated but never emarginate as in T. pubescens  (Figs 7, 15). Lateral projections subacute. Punctation of T6 finer and more scattered in comparison with T. pubescens  . Median projection of T7 parallel-sided, apex truncated (Figs 8, 15).

Pubescence on thorax dense and relatively long; pubescence on vertex and dorsal side of mesosoma reddish brown. Pubescence in the other species of the complex is inclined to be dull white to yellow-brown, but this difference can only be seen when series of specimens are compared.


One of the males examined from Greece shows a colouration pattern which is different from all other specimens: The integument is shining black (not dull black), the paraocular area yellow (yellow maculation not reaching top of eye); one very small yellow spot on vertex and narrow yellow remnants of the anterolateral L-shaped band on the scutum; one small yellow lateral spot on each side of T1-T4, and additionally two small yellow median spots on T3 and T4 (no bands). While all yellow colouration is thus much reduced on the body, this specimen shows elongate light brown stripes on fore- and middle tibiae and one dark brown stripe on each hind tibia. While this colour pattern is entirely different from all other specimens examined in the T. pubescens  complex, the size, the form of the clypeus, and the shape of T6 and T7 are in conformity with T. balcanica  sp. n., and it is thought that this specimen belongs to this species.

Derivatio nominis.

The name is derived from the Balkans.


The distribution area of Trachusa balcanica  sp. n. extends from central Hungary (Budapest) in the north over central Serbia to western Bulgaria. In the southwestern part of its range, it extends over Macedonia to northern and central Greece. Countries of occurrence are: Bulgaria, Greece, Hungary, Macedonia (F.Y.R.), and Serbia. Records from Romania (a female from Tulcea, 1895, J. J. Mann leg., cMAV, and a female listed by Calefariu 2017) and Moldova ( Stratan and Andreev 2015) could not be examined, or not to the extent necessary to allow an unambiguous assignment to this species ( T. pubescens  ?).

Flower preference.

Mocsáry (1884) found the species in central Hungary in July 1878 abundantly at Stachys germanica  . Friese (1898) collected it at Genista  in Serbia.


On 01.06.1965 and Prilep, FYR Macedonia, K. Warncke collected three males and a female of T. pubescens  s. l., apparently together. While two males can be unambiguously attributed to T. balcanica  sp. n. (shape of clypeus, in one male also shape of genitalia examined), the third male has the apical margin of the clypeus as in T. pubescens  s. str. and was attributed to that species.