Thyreus jansseni Wood, 2025

Wood, Thomas, Leclercq, Vincent, Schmid-Egger, Christian & Praz, Christophe, 2025, A contribution to the knowledge of the genus Thyreus Panzer in the West and Central Palaearctic (Hymenoptera, Apidae), with two new species, taxonomic updates, host relationships, and a key to European species, Deutsche Entomologische Zeitschrift 72 (2), pp. 259-302 : 259-302

publication ID	https://doi.org/10.3897/dez.72.164496
publication LSID	lsid:zoobank.org:pub:8DD12B45-AE34-45B8-A8FB-0C3A13478718
DOI	https://doi.org/10.5281/zenodo.17525159
persistent identifier	https://treatment.plazi.org/id/043CB51F-BBD4-5A1A-9AD9-B9640D3D47E9
treatment provided by	Deutsche Entomologische Zeitschrift by Pensoft
scientific name	Thyreus jansseni Wood
status	sp. nov.

Treatment

Thyreus jansseni Wood sp. nov.

Type materials.

Holotype: Kyrgyzstan • 1 ♂; Kirpichny ; 42.4047°N, 77.8645°E; 11 Jul. 2019; K. Janssen leg.; RMNH; RMNH.INS.1714348 (BOLD accession number WPATW 953-22) GoogleMaps .

Paratypes: Afghanistan • 2 ♂; Ghazni province, Jaghori district ; 30 Jun. 1997; G. G. M. Schulten leg.; RMNH; ZMA.INS.5144956 – ZMA.INS.5144957 ; Kyrgyzstan • 1 ♂; Narynskaya, Distr. Dzhumgalsky, S Kyzyl-Oy ; 1750–1800 m a. s. l.; 5–6 Jul. 1996; H. Rausch leg.; OÖLM .

Diagnosis.

Thyreus jansseni can be recognised as a typical Thyreus (“ Other species of Thyreus Panzer ”) due to the large flattened scutellum which posteriorly projects over the metanotum and which is uniformly flattened over its entire surface and which is not medially sulcate (Fig. 2 C View Figure 2 ), combined with the genital capsule with a large gonostylus which is covered with long hairs (Fig. 3 G View Figure 3 ). Due to the white hairs on T 1 which form C-shaped patches (Fig. 3 C View Figure 3 ; basally slightly incurving towards the scutellum), the scutellum with punctures separated by 0.5–1 puncture diameters and with polished shining interspaces (Fig. 2 C View Figure 2 ), with S 8 produced into two projections which are apically truncate and which curve laterally, thus appearing to be “ golf-club ” - shaped (Fig. 3 E View Figure 3 ), and the genital capsule with a large apically truncate projection and basal dorsally projecting and acutely pointed section oriented roughly 90 ° relative to the larger lobe (Fig. 3 G View Figure 3 ), it can be confused only with Thyreus picaron (Figs 2 D View Figure 2 , 3 D View Figure 3 , 3 F View Figure 3 , 3 H View Figure 3 ).

Thyreus jansseni can be separated from T. picaron due to the smaller body size of 10 mm ( 12–13 mm in T. picaron ), scutellum 1.5 times wider than long with the median notch barely indicated (Fig. 2 C View Figure 2 ; in T. picaron with the scutellum 1.6 times wider than long, and with the median notch deep and strongly indicated, Fig. 2 D View Figure 2 ), antennal segments viewed dorsally with a strong division between the anterior face which is covered with fine shining scales and the dull posterior face (Fig. 2 E View Figure 2 ; in T. picaron with a weaker division between the shinier anterior and duller posterior faces of the antenna, Fig. 2 F View Figure 2 ), posterior faces of the antennal segments with very weakly impressed paired rhinaria, those situated more ventrally very difficult to see (in T. picaron with the posterior faces of the antennal segments with strongly impressed paired rhinaria, dorsal and ventral rhinaria equally visible), and posterior basitarsus with only a small white hair fringe dorsally (Fig. 3 A View Figure 3 ; in T. picaron with the hind basitarsus entirely covered in fine white hairs, these becoming thicker dorsally, Fig. 3 B View Figure 3 ).

Description.

Female. Unknown, though likely described by Marikovskaya (1992) as T. picaron auctorum (see below).

Male. Body length: 10 mm (Fig. 2 A View Figure 2 ). Head: Dark, 1.3 times wider than long (Fig. 2 B View Figure 2 ). Clypeus flattened, densely punctate, punctures separated by ≤ 0.5 puncture diameters, surface between punctures shining. Labrum rounded rectangular, almost 2 times longer than wide, apex with elevated subapical transverse carina forming obtusely pointed tooth; labrum basally weakly produced into two tubercles laterally. Gena narrower than width of compound eye; ocelloccipital distance 2 times diameter of lateral ocellus. Hind margin of vertex with narrow obscure slightly raised carina-like rim. Face between antennal insertions with raised longitudinal carina, reducing in height and becoming medial impression on frons anterior to median ocellus. Frons punctate, punctures separated by ≤ 0.5 puncture diameters, becoming sparser in area anterior to median ocellus; vertex behind ocellar triangle densely punctate, areas adjacent to lateral ocelli impunctate, smooth and shining. Face with abundant white pubescence, decumbent on lower half of face below antennal insertions. Gena ventrally with dark hairs, dorsally with scattered white hairs. Antenna dark, A 4–13 with anterior faces lightened by presence of greyish scales; posterior faces of A 4–13 with fine granular microreticulation, surface dull and strongly contrasting scales of anterior faces (Fig. 2 E View Figure 2 ). Posterior faces of A 4–13 with small and superficially impressed paired rhinaria placed close to junction with preceding segment, ventral rhinaria almost undetectable. A 3 0.8 times length of A 4.

Mesosoma: Scutum and scutellum punctate, punctures separated by 0.5–2 puncture diameters but typically by 1 puncture diameter, surface between punctures smooth and shining. Scutellum 1.5 times wider than long, posterior margin wavy, with small median notch, posteriorly with moderate tuft of white hair projecting from ventral surface (Fig. 2 C View Figure 2 ). Axilla flush with outer margin of scutellum, scutellum and axilla with dark hairs which do not obscure surface. Mesepisternum densely punctate medially, punctures confluent with slightly raised ridges, becoming sparser ventrally, here separated by 0.5–2 puncture diameters. Legs dark, with abundant white pubescence on outer face of tibiae, covering entirety of fore and mid-tibiae and basal ½ of hind tibiae. Hind basitarsus predominantly with dark hairs, dorsal surface with small white hair fringe (Fig. 3 A View Figure 3 ). Forewing weakly infuscate.

Metasoma: Terga dark, tergal discs punctate with hair-bearing punctures, punctures presenting short, posteriorly projecting black plumose hairs; punctures separated by 0.5–1 puncture diameters (Fig. 3 C View Figure 3 ). T 1 with L-shaped white hair patch laterally, apically extending further towards centre of tergum than basally, hairs predominantly adpressed, some loose hairs found basolaterally. T 2 with almost rectangular patches of white hairs laterally, with narrow extension towards base of disc laterally. T 3–5 with rectangular patches of white adpressed hairs, not forming complete bands. T 7 with apical margin essentially straight, weakly wavy. S 8 delicate, posterior projections with narrow stem before turning 90 ° degrees to form small laterally projecting discs (Fig. 3 E View Figure 3 ). Genital capsule compact, almost rounded, gonocoxa slightly broadened and truncate apically, in basal part with dorsally projecting acutely pointed lobe rotated 90 ° relative to truncate section (Fig. 3 G View Figure 3 ). Basal and apical parts of gonostylus covered with long brown hairs, hairs simple apically, weakly plumose basally.

Notes.

Marikovskaya (1992) described the female of “ Thyreus picaron ” from the Alai Mountains in Kyrgyzstan, near the village of Дараут-Курган (= Daroot-Korgon), with 12 ♀ and 7 ♂ specimens collected between 15 and 16 July 1986. Based on Marikovskaya’s writing and illustrations, it is highly likely that she was dealing with T. jansseni and hence described the female of this species. Unfortunately, Marikovskaya’s collection appears to have been destroyed (Pierre Rasmont, pers. comm.), which does not allow us to draw conclusions with certainty. Moreover, Marikovskaya did not give the size of the female or male specimens, but she did indicate that the host of her species was Anthophora ( Mystacanthophora) borealis Morawitz, 1865 . This species, and indeed the subgenus of bees, is very rare in Europe and is found in temperate to boreal habitats, which do not overlap at all with the observed distribution of T. picaron in Europe and the Near East, which is Mediterranean in character. Anthophora borealis is typically 10–11 mm in length, which is simply too small to host T. picaron , which has males 12–13 mm in length, and females will of course be slightly larger on average. Thyreus picaron is likely attacking larger Amegilla ( Amegilla) species (see below), which would account for its much larger body size relative to T. jansseni . Anthophora borealis and, possibly other species of Mystacanthophora Brooks, 1988, therefore seem to be the likely host (s) of T. jansseni .

Etymology.

The name is to recognise Kobe Janssen ( Belgium), who very generously shared large numbers of bee specimens (including Melectini ) with the lead author for a long period of time.

Distribution.

Kyrgyzstan and Afghanistan. Likely present in other Central Asian countries, given Lieftinck’s (1968: 92) paratypes of T. picaron from Uzbekistan (Dzhuma) and Kazakhstan (Zharkent, Kazaly) (specimens in St. Petersburg, Oxford, and Prague). Examination of these specimens is necessary to clearly delineate the distributions of these two species. Searches in the OUMNH (TJW, August 2025) could not locate any “ T. picaron ” specimens or registration of such in the type catalogue.