The Trachusa interrupta species complex

The Trachusa interrupta species complex belongs to the subgenus Trachusa (Paraanthidium) and comprises eight species: Trachusa interrupta (Fabricius, 1781), T. integra (Eversmann, 1852) stat. resurr., T. anatolica sp. n., T. varia (Olivier, 1789) stat. resurr., T. maghrebensis sp. n., T. heinzi Dubitzky, 2007, T. grandicornis sp. n., and T. taurica sp. n.

Description. The description given here characterises all species of the complex. The colouration of the maculation is yellow (cream, ivory) in seven species and red in one species only ( T. varia).

Female. 10–14 mm. Clypeus yellow or red, with relatively wide, black apical margin; mandible with one large apical and three smaller, obtuse teeth; yellow or red paraocular area reaching top of eye; supraclypeal area yellow/ red; gena with yellow/red maculation of varying size (extending over almost the entire gena in some species); antenna dark; scutum black, often with a yellow or red L-shaped or boomerang-shaped anterolateral stripe; scutellum overhanging metanotum, shallowly emarginate in the middle; scutellum and axillae black or black with up to four yellow/red spots; pronotal lobe with sharp lamella; tegula bi-coloured black/brown and yellow/red; T1–T4 black with yellow or red bands, uninterrupted, interrupted or attenuated medially; tibiae and tarsi golden yellow or orangeyellow, tibiae often with some longish black maculation on inner sides; wings dark brown infuscated; ventral scopa white.

Male. 11–15 mm. Clypeus yellow with crenulated or finely serrate apical margin; mandible narrow, yellow, with three black, subacute teeth; antenna longer than in female; scape yellow beneath; scutum entirely black or black with yellow L-shaped or boomerang-shaped anterolateral stripe; scutellum and axillae with up to four yellow spots; terga with yellow bands, often interrupted on anterior terga; T6 yellow with dark V-shaped anterior maculation and lamellate distal projection medially; T7 lamellate with a deep rounded emargination apically; gonoforceps Y-shaped with one longer, yellow arm protruding beyond metasoma and visible dorsally; S2 with long whitish hair which covers combs when abdomen is curled inward in resting position; two small median subapical patches of black bristles often present on S4; S3 with a deep V-shaped median emargination; median combs of black bristles on rim of S5.

The closest relative is Trachusa (Paraanthidium) dumerlei (Warncke, 1980), which has a similar habitus and colour pattern. The male is distinguished by the shape of the genitalia [gonoforceps bifid with deep emargination in the interrupta complex (Figs 17, 41) vs. shallow emargination between arms in T. dumerlei (figure in Kasparek 2017a: 103)] and the form of the black combs on S6 [combs extend to the lateral apices in the interrupta complex (Fig. 17) but not reaching the apices in T. dumerlei (figure in Kasparek 2017a: 103)]. The female of T. dumerlei has an interrupted yellow band on T5 (never interrupted in the T. interrupta complex), mandibles with yellow colouration (entirely black in the interrupta complex), and a big yellow maculation on the mesepisternum (black with at most a very small yellow spot in the interrupta complex). Detailed descriptions and illustrations are given in Kas- parek (2017a). Trachusa dumerlei is here considered to be sufficiently distinct and is not placed in the interrupta complex.