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

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 Thomas Wood1, Vincent Leclercq2, Christian Schmid-Egger3, Christophe Praz4,5 1 Naturalis Biodiversity Center, Darwinweg 2, 2333 CR, Leiden, Netherlands 2 Observatoire des Abeilles, 10 D Rue Alfred Marpaux 21000 Dijon, France 3 Fischerstraße 1, 10317, Berlin, Germany 4 University of Neuchatel, Neuchâtel, Switzerland 5 Info Fauna - Swiss Zoological Records Center, Neuchâtel, Switzerland https://zoobank.org/8DD12B45-AE34-45B8-A8FB-0C3A13478718 Corresponding author: Thomas Wood ([email protected]) Academic editor: Dominique Zimmermann ♦ Received 8 July 2025 ♦ Accepted 10 October 2025 ♦ Published 4 November 2025 Abstract Thyreus Panzer, 1806, is a moderately sized bee genus containing about 115 species with an Old World distribution matching that of their principal hosts, bees of the genus Amegilla Friese, 1897. The Palaearctic fauna was revised during the mid-20th century but has received relatively little attention since then. New collections, examination of museum specimens, and DNA barcoding have improved our understanding of this genus in the West and Central Palaearctic. The previously unknown sexes of T. parthenope Lieftinck, 1968, T. picaron Lieftinck, 1968, and T. priesneri Lieftinck, 1968, are identified and clarified. New host data are presented for Thyreus hellenicus Lieftinck, 1968, in Greece, where it parasitises Anthophora (Paramegilla) superans Walker, 1871 = Anthophora (Paramegilla) inclyta Walker, 1871 syn. nov. (= Anthophora dubia Eversmann, 1852 sensu auctorum). A lectotype is designated for Thyreus truncatus (Pérez, 1884), and its range and status are discussed. New records are presented to resolve the distributional ranges of confused or poorly studied species, along with new host data. Thyreus praevalens (Kohl, 1905) is newly reported for Europe from Greece. Specimens previously referred to as “T. picaron” in Central Asia do not belong to that species and are newly described as Thyreus jansseni Wood, sp. nov. (Kyrgyzstan and Afghanistan). A further new species in the scutellaris group is described, Thyreus impressus Wood, sp. nov. (Kyrgyzstan). A modified and updated identification key to the 12 European members of the genus is presented, with the aim of stimulating work on this challenging bee genus. Key Words DNA barcoding, host-parasite relationship, identification key, museum collections, new species Introduction The genus Thyreus is the most species-rich member of the obligately parasitic bee tribe Melectini, with about 115 species known across the Old World, representing approximately 55% of the known species richness (Michener 2007; Ascher and Pickering 2025). Melectine bees present numerous taxonomic issues, both in terms of how genera are defined and recognised (e.g. Lieftinck 1972, 1983; Rightmyer and Engel 2003; Michener 2007; Onuferko et al. 2021; Orr et al. 2024) and at the species level. Due to their parasitic nature, predominantly attacking bees of the subfamily Anthophorinae (see Bossert et al. 2019; Orr et al. 2024), melectine species exhibit Dtsch. Entomol. Z. 72 (2) 2025, 259–302|DOI 10.3897/dez.72.164496 Copyright Thomas Wood et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species260 largely conserved and homogeneous morphology, rendering species recognition and delineation challenging. As the largest genus of Melectini, this statement naturally applies to Thyreus. The genus was in a largely chaotic state until the revisionary works of Lieftinck (mainly 1959a, 1962, 1968), who dealt with the Palaearctic, Indo-Malayan, and Australasian faunas. Lieftinck never addressed the Afrotropical fauna, and whilst a revision has been conducted (Eardley 1991), additional work is needed due to the long history of study, ancient type material, and complex nature of the genus. Within the Palaearctic fauna, Lieftinck’s (1968) revision resolved many long-running issues. Older works such as Meyer (1921), published before Lieftinck’s revision, are largely unusable due to the high degree of taxonomic uncertainty, lack of type revision, taxa described from material that is now lost, and generally muddled concepts; this can be seen when examining historical specimens identified by Meyer, these often being completely misidentified (TJW, pers. obs.). De Beaumont (1940) made a major contribution by working on the West European fauna and clarifying the incorrect application of the name Thyreus scutellaris (Fabricius, 1781), and these improvements were cemented by Lieftinck’s more comprehensive work. Since then, the genus has received relatively little taxonomic attention in the Palaearctic (Marikovskaya 1992; Schwarz 1993), with comparatively more attention paid to the Afrotropical fauna (Eardley 1991; Straka and Engel 2012; Alqarni et al. 2014; Engel 2014). However, recent work has demonstrated genuine range expansions (SchmidEgger et al. 2022) and taxonomic complexity (Wood 2023) in the fauna of Europe and the Mediterranean basin. There has also been an opportunity to study the West and Central Palaearctic fauna using DNA barcodes, which provided both clarity and introduced new complexity. The purpose of the present work is to present these new data on the genus Thyreus in the West and Central Palaearctic and to produce an improved identification key to the European fauna in order to stimulate new work on this complex group. Methodology Genetics Collected West and Central Palaearctic Thyreus specimens were barcoded using different techniques. For most specimens (sequence prefix WPATW), a single midleg was removed from pinned specimens and sent to the Canadian Centre for DNA Barcoding (CCDB) in Guelph, Canada, for DNA extraction and sequencing; specimens were sequenced following standardised high-throughput protocols (Ivanova et al. 2006). BeeCox1F1/BeeCox1R2 primers (Bleidorn and Henze 2021) were used to target the COI-5 region. Sequences with the prefix BCHYM were generated following the methodology of Schmidt et al. (2015). Sequences with the prefix HYMAA were generated at the University of Neuchâtel, Switzerland, following the methodology outlined in Praz et al. (2019), using the forward primers LepF or UAE3 with the reverse primer LepF (see Praz et al. 2019). Phylogenetic trees were supplemented with additional published sequences (e.g. Schmidt et al. 2015; Wood 2023; Wood et al. 2024) that were downloaded from GenBank (https://www.ncbi.nlm.nih.gov/genbank/) and the Barcode of Life Data System. Also used were newly generated sequences from the Biodiversity Genomics Europe project, based on specimens from the Naturalis Biodiversity Center that were selected and curated by TJW. Sequences are available at: https://portal.boldsystems.org/result?query=BGENL[recordsetcode]. Taxa were selected from within the West and Central Palaearctic framework of this study (defined below), without including any of the many additional available extralimital sequences of Thyreus. Sequences were aligned using MAFFT (Katoh and Standley 2013). Aligned sequences were analysed in Seaview (Gouy et al. 2010) using a maximum-likelihood analysis, which was run with 1,000 bootstraps. Intraand interspecific distances were calculated using MEGA-X (Kumar et al. 2018). Morphological and taxonomic concepts Morphological terminology follows Michener (2007), except for the marginal “zones” of the terga, which are referred to as marginal “areas”; antennomeres, which are numbered 1–12 (female) and 1–13 (male) and abbreviated as “A”; and the use of the word “rhinaria” to refer to the impressed pits on the posterior face of the antennal segments (see Lieftinck 1968). Metasomal terga are abbreviated as “T”, and metasomal sterna as “S”. For one diagnosis, the relative breadth of the scutellum is presented. This was measured as the distance between the apical points of the axillae (the breadth, i.e. the maximum width of the scutellum) divided by the distance between the base of the scutellum (straight junction with the scutum) and the posterior scutellar points (the length, i.e. the maximum length of the scutellum). Measurements were obtained from photographs, not using a calibrated microscope, and hence are presented as a ratio. Unless explicitly stated, all specimens were identified by TJW. An identification key is presented for Thyreus species occurring in Europe as defined in Ghisbain and Rosa et al. (2023), to facilitate their identification. Put simply, this includes Europe east to the Ural Mountains, European Russia south to but not including the North Caucasus, Turkey in Europe (east to the Bosporus), all Mediterranean islands including Cyprus, and the Macaronesian islands excluding the Cape Verde islands. Whilst the West and Central Palaearctic are poorly and inconsistently defined in the literature, from the perspective of the genus Thyreus, these two areas together are considered to include North Africa, the Arabian Peninsula, Iran, and Central Asia (all “-stan” countries, including Afghanistan and Pakistan). Photographs were taken using an Olympus E-M1 Mark II with a 60 mm macro lens. Additional close-ups were taken with the addition of a Mitutoyo M Plan Apo Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 261 10X infinity-corrected objective lens in combination with an Olympus M.Zuiko 2× teleconverter lens, a 10 mm Kenko DG extension tube, and a Meike MK-P-AF3B 10 mm extension tube. Photographs were stacked using Helicon Focus B (HeliconSoft, Ukraine), and plates were prepared in GNU Image Manipulation Program (GIMP) 2.10. Post-processing of some images was carried out in Photoshop Elements (Adobe Systems, USA) to improve lighting and highlight specific characters. Results are presented in the following order: (1) genetics, (2) description of new species, (3) problematic taxa identified by genetic study, (4) description of missing sexes, (5) new distributional data and range clarifications, and (6) new identification key for European species. In the summary of distributions, new country records are marked with an asterisk “*”. New data on host relationships are presented for individual species where sufficient information is available to draw convincing conclusions. Abbreviations of specimen repositories CSE Personal collection of Christian SchmidEgger, Berlin, Germany EDC Personal collection of Eric Dufrêne, SaintHippolyte-du-Fort, France KJCB Personal collection of Kobe Janssen, Zonhoven, Belgium LRC Personal collection of Francisco La Roche, San Cristóbal de La Laguna, Tenerife, Spain MNCN Museo Nacional de Ciencias Naturales, Madrid, Spain MNHN Muséum national d’Histoire naturelle, Paris, France MSNG Museo Civico di Storia Naturale “Giacomo Doria”, Genoa, Italy NHMD Natural History Museum of Denmark, Copenhagen, Denmark NHMUK Natural History Museum, London, United Kingdom NMB Naturhistorisches Museum Bern, Bern, Switzerland NHMW Naturhistorisches Museum Wien, Vienna, Austria OÖLM Oberösterreichisches Landesmuseum, Linz, Austria OUMNH Oxford University Museum of Natural History, Oxford, United Kingdom RMNH Naturalis Biodiversity Center, Leiden, the Netherlands TJWC Personal collection of Thomas J. Wood, Leiden, the Netherlands VLC Personal collection of Vincent Leclercq, Dijon, France WHLC Personal collection of Wolf-Harald Liebig, Bad Muskau, Germany ZMHB Museum für Naturkunde, Berlin, Germany ZSI Zoological Survey of India, Kolkata, India Results Genetics Two main clades were observed in the COI barcode tree (Fig. 1). The first had bootstrap support of 97 and contained the most commonly collected and observed West and Central Palaearctic Thyreus species, such as T. histrionicus (Illiger, 1806) and T. ramosus (Lepeletier, 1841). The second group had bootstrap support of 87 and contained T. affinis (Morawitz, 1873), T. elegans (Morawitz, 1877) sensu lato, a newly described species Thyreus impressus Wood, sp. nov., and Thyreus scutellaris; this clade is best referred to as the scutellaris-group (sensu Lieftinck 1968). From the RMNH collection, it was possible to generate a long 1,498 bp sequence from a specimen of T. scutellaris from Ufa in southern European Russia (BGENL2290-24), which was included in Lieftinck’s (1968: 46) revision. Thyreus scutellaris was separated from its nearest neighbour, T. impressus, by an average genetic distance of 8.05% (range 8.05–8.05%). The new species T. impressus was strongly separated by 10.63% (range 10.33–10.96%) from T. elegans sensu lato and by 9.74% from T. affinis (range 9.57–9.88%). For T. elegans, four barcodes were generated. Specimens from Morocco, the United Arab Emirates, and Iran showed similar barcodes, separated by an average of 1.12% (range 1.07–1.22%). However, the specimen from south-eastern Kazakhstan (Shonzhy) was strongly separated from these three sequences by an average of 10.75% (range 10.49– 10.96%). The issues associated with T. elegans sensu lato are discussed below. Within the clade of more commonly collected Thyreus species (“Other species of Thyreus Panzer” in Lieftinck 1968), results from T. picaron Lieftinck, 1968 and T. truncatus (Pérez, 1884) require investigation. Thyreus picaron sequences from Spain, Italy, Albania, and Iran formed a monophyletic group with average intraspecific variation of 0.31% (range 0.00–0.76%), receiving bootstrap support of 100. This group differed from the single T. aff. picaron sequence from Kyrgyzstan by an average of 6.58% (range 6.40–6.69%), with the Kyrgyz sequence not falling immediately adjacent to the T. picaron cluster. It is described below as Thyreus jansseni Wood, sp. nov. For T. truncatus, the picture was complex. Three clades were observed (Fig. 1). The first contained specimens from central Spain, which received bootstrap support of 97; this can be referred to as the “Iberian lineage”. The second contained specimens from south-western France (Aude) and south-eastern France (Bouches-du-Rhône), which received bootstrap support of 88; this can be referred to as the “French lineage”. Finally, the third contained specimens from southern France (Gard), Switzerland, Germany, Poland, and Kyrgyzstan and received bootstrap support of 96; this can be referred to as the “Euro-Siberian lineage”. Variation within lineages was low: an average of 0.21% (range 0.15–0.31%) in the Iberian lineage, 0.00% in the French lineage, and 0.35% (range 0.00–0.83%) in the dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species262 Euro-Siberian lineage, resulting in the high observed bootstrap supports. Variation between clades was 3.80% (range 3.50–4.16%) between the Iberian and Euro-Siberian clades, 3.31% (range 3.12–3.48%) between the Iberian and French clades, and 1.79% (range 1.53–2.13%) between the French and Euro-Siberian clades. All other species in the group of commonly collected Thyreus received bootstrap support between 97 and 100 and were well defined genetically. Figure 1. Phylogenetic tree (maximum likelihood) of Thyreus Panzer, 1806 species, based on fragments of the mitochondrial COI gene. Eupavlovskia obscura (Friese, 1895) is used as an outgroup. Numbers adjacent to branches represent bootstrap support (values < 75% are omitted). Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 263 New species descriptions Thyreus jansseni Wood, sp. nov. https://zoobank.org/37102F10-26D5-4F30-AAF3-64FAC7D3EC1A 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 WPATW953-22). 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. 2C), combined with the genital capsule with a large gonostylus which is covered with long hairs (Fig. 3G). Due to the white hairs on T1 which form C-shaped patches (Fig. 3C; basally slightly incurving towards the scutellum), the scutellum with punctures separated by 0.5–1 puncture diameters and with polished shining interspaces (Fig. 2C), with S8 produced into two projections which are apically truncate and which curve laterally, thus appearing to be “golf-club”-shaped (Fig. 3E), 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. 3G), it can be confused only with Thyreus picaron (Figs 2D, 3D, 3F, 3H). 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. 2C; in T. picaron with the scutellum 1.6 times wider than long, and with the median notch deep and strongly indicated, Fig. 2D), 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. 2E; in T. picaron with a weaker division between the shinier anterior and duller posterior faces of the antenna, Fig. 2F), 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. 3A; in T. picaron with the hind basitarsus entirely covered in fine white hairs, these becoming thicker dorsally, Fig. 3B). Description. Female. Unknown, though likely described by Marikovskaya (1992) as T. picaron auctorum (see below). Male. Body length: 10 mm (Fig. 2A). Head: Dark, 1.3 times wider than long (Fig. 2B). 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, A4–13 with anterior faces lightened by presence of greyish scales; posterior faces of A4–13 with fine granular microreticulation, surface dull and strongly contrasting scales of anterior faces (Fig. 2E). Posterior faces of A4–13 with small and superficially impressed paired rhinaria placed close to junction with preceding segment, ventral rhinaria almost undetectable. A3 0.8 times length of A4. 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. 2C). 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. 3A). 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. 3C). T1 with L-shaped white hair patch laterally, apically extending further towards centre of tergum than basally, hairs predominantly adpressed, some loose hairs found basolaterally. T2 with almost rectangular patches of white hairs laterally, with narrow extension towards base of disc laterally. T3–5 with rectangular patches of white adpressed hairs, not forming complete bands. T7 with apical margin essentially straight, weakly wavy. S8 delicate, posterior projections with narrow stem before turning 90° degrees to form small laterally projecting discs (Fig. 3E). 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. 3G). Basal and apical parts of gonostylus covered with long brown hairs, hairs simple apically, weakly plumose basally. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species264 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 Figure 2. Thyreus jansseni Wood, sp. nov. male holotype (RMNH). A. Habitus, lateral view; B. Face, frontal view; C. Scutellum, dorsal view; E. Antenna, dorsal view. Thyreus picaron Lieftinck, 1968 male (TJWC); D. Scutellum, dorsal view; F. Antenna, dorsal view. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 265 Figure 3. Thyreus jansseni Wood, sp. nov. male holotype (RMNH). A. Hind basitarsus, lateral view; C. Metasoma, dorsal view; E. S8, dorsal view; G. Genital capsule, dorsal view; Thyreus picaron Lieftinck, 1968 male (TJWC); B. Hind basitarsus, lateral view; D. Metasoma, dorsal view; F. S8, ventrolateral view; H. Genital capsule, dorsal view. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species266 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. Thyreus impressus Wood, sp. nov. https://zoobank.org8E37B113-D55C-4FB7-8874-2A9D628367DE Type materials. Holotype: Kyrgyzstan • 1♂; 45 km W of Naryn; 41.4160°N, 75.3969°E; 20 Jul. 2019; K. Janssen leg.; RMNH; RMNH.INS.1714347 (BOLD accession number WPATW950-22). Paratype: Kyrgyzstan • 1♂; 45 km W of Naryn; 20 Jul. 2019; 41.4160°N, 75.3969°E; K. Janssen leg.; TJWC (BOLD accession number WPATW951-22). Diagnosis. Thyreus impressus can be placed into the scutellaris-group due to the genital capsule, which is simple, with the gonostylus greatly reduced in size and pointed-triangular without an additional dorsal projection (Fig. 5E), and the gonostylus with only a few inconspicuous hairs. It can be separated from all other members of the group except T. scutellaris by the structure of the scutellum, which is medially impressed and sulcate, with the axillae slightly diverging from the outer margins of the scutellum and produced into slight but distinct points (Fig. 4C), and due to the white hair patches at the base and on the marginal area of T1, both widely separated medially and laterally by abundant black hairs, thus forming 4 distinct patches in dorsal view (Fig. 4D). The two species are similar, but T. impressus can be recognised due to the gonostylus which is small and acutely pointed, with the inner margin straight (Fig. 5E; in T. scutellaris with the gonostylus more elongate and apically blunt to rounded, and the inner margin with a distinct subapical kink, Fig. 5F; see also illustration in Lieftinck 1968: 46), in frontal view with A3 only slightly exceeding A4 in length (Fig. 5A; in T. scutellaris with A3 clearly exceeding A4 in length, approaching A4+5, Fig. 5B), and the posterior faces of the antennal segments with strongly produced Figure 4. Thyreus impressus Wood, sp. nov. male holotype (RMNH). A. Habitus, lateral view; B. Face, frontal view; C. Scutellum, dorsal view; D. Metasoma, dorsal view. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 267 individual rhinaria (not paired), clearly visible on the posterior face of A13 (Fig. 5C; in T. scutellaris with the posterior faces of the antennal segments with weakly produced individual rhinaria, that on A13 so small and weak as to not be immediately visible, Fig. 5D). Description. Female. Unknown. Male. Body length: 9.5–10 mm (Fig. 4A). Head: Dark, 1.25 times wider than long (Fig. 4B). Clypeus flattened, densely punctate, punctures confluent, surface dull with exception of narrow shining margin. Labrum rounded rectangular, 1.5 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 1.5 times diameter of lateral ocellus. Hind margin of vertex with narrow obscure slightly raised carina-like rim. Face between antennal insertions with weak raised longitudinal carina, rapidly reducing in height and becoming medial impression on frons anterior to median ocellus. Frons punctate, punctures separated by ≤ 0.5 puncture diameters, punctation becoming slightly weaker on vertex, here separated by up to 1 puncture diameter. Face with abundant white pubescence, decumbent on lower half of face below antennal insertions. Figure 5. Thyreus impressus Wood, sp. nov. male holotype (RMNH). A. A3–5, frontal view; C. A9–13, posterior view; E. Genital capsule, detail of gonostylus, dorsolateral view; Thyreus scutellaris (Fabricius, 1781) male (TJWC); B. A3–5, frontal view; D. A9– 13, posterior view; F. Genital capsule, detail of gonostylus, dorsal view. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species274 The presence of white hair patches on the axillae gives T. parthenope a similar appearance to T. hyalinatus (Vachal, 1903) (Israel, Egypt, Sudan, Chad*, Eritrea, Djibouti, Saudi Arabia, Qatar*, United Arab Emirates*, Oman*, Iran; Lieftinck 1968), but the two species can be separated by the presence of the white hair spots on the scutellum of T. parthenope (absent in T. hyalinatus). The two species can also be separated due to the structure of the mesepisternum in its ventral half (the part not covered with pubescence), which has the punctures dense and very weakly separated in T. parthenope (punctures almost confluent), whereas T. hyalinatus shows clear shining spaces between the punctures, these spaces often wider than the diameter of a puncture. These characters, in combination with the distribution, which is currently restricted to the southern half of the Arabian Peninsula and probably south-eastern Egypt allows recognition, particularly in combination with concurrently active males. Description. Female. Body length: 12 mm (Fig. 11A). Head: Dark, 1.3 times wider than long (Fig. 11B). Clypeus very weakly domed, densely punctate, punctures separated by ≤ 0.5 puncture diameters, interspaces shining. Labrum rounded rectangular, 1.5 times longer than broad, with longitudinal impressed midline terminating subapically, apex with tiny slightly projecting tooth; labrum basally strongly produced into two tubercles laterally, outer half of tubercules polished and shining, impunctate. Gena much narrower than width of compound eye; ocelloccipital distance 2 times diameter of lateral ocellus. Face between antennal insertions with weakly raised longitudinal carina, not strongly extending dorsally. Frons densely punctate, punctures separated by ≤ 0.5 puncture diameters, becoming weaker laterally adjacent to lateral ocelli, here with polished shining impunctate space subequal to diameter of lateral ocellus (Fig. 11C). Head almost entirely white-haired, with brownish hairs restricted to mandibles. Antenna dark, measured along ventral surface A3, more or less equalling A4. Mesosoma: Scutum and scutellum densely punctate, punctures separated by ≤ 0.5 puncture diameters, up to 1 puncture diameter on scutellum, surface between punctures shiny. Scutum with contrasting black and white pubescence, white pubescence along anterior margin, lateral margins, medially with longitudinal line covering anterior ¾ of scutum, anterolaterally with two white spots, posterolaterally with two thick patches along posterior margin (Fig. 11D). Axilla with clear patch of white plumose adpressed hairs. Scutellum postero-laterally with two patches of white plumose adpressed hairs. Scutellum produced into two posteriorly projecting points, between these with shallow emargination, scutellum itself relatively long, maximum width 1.5 times longer than maximum length; emargination between posterior points with thick broad tuft of white hairs emerging from ventral surface (Fig. 11E). Mesepisternum in dorsal ½ covered with dense patch of adpressed white hairs, entirely obscuring surface; in ventral ½ with surface lacking hairs, densely and regularly punctate, punctures almost confluent. Legs dark, outer surface of tibiae and tarsi covered with dense felt-like white hairs, mid and hind tibiae with short dark spines projecting through pubescence. Forewing almost entirely hyaline, with only weak infuscation adjacent to a few veins. Metasoma: Terga dark, tergal discs densely punctate with hair-bearing punctures, punctures presenting Figure 10. Distribution of Thyreus truncatus (Pérez, 1884) (red circles) along with its host Tetralonia dentata (Germar, 1839) (open blue triangles). Distributional data are not comprehensive. 25N 30N 35N 40N 45N 50N 55N 60N 65N 0 20E 40E 60E 80E Longitude Latitude Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 275 short, posteriorly projecting black plumose hairs, punctures separated by 0.5–2 puncture diameters (Fig. 11F). T1 laterally with wide C-shaped patch of white hairs, hairs along apical margin of tergum reaching further towards centre of disc than hairs along basal margin of tergum. T2 with L-shaped patch of white hairs, T3–5 with rectangular white hair patches, hair patches on all terga broadly separated medially, never complete. Pygidial plate weakly converging apically, lateral margins slightly raised, medially with strongly humped longitudinal bump, surface dull. Distribution. Egypt (presumably southern Egypt), Sudan*, Saudi Arabia*, Yemen, United Arab Emirates*, Oman* (Lieftinck 1968). Other material examined. (Thyreus hyalinatus) chad • 1♀; Tchad, Ndjamena; 30 Mar. 1978; G.G.M. Schulten leg.; RMNH • 1♀; Tchad, Ndjamena; 22 Jun. – 6 Jul. 1978; G.G.M. Schulten leg.; RMNH; oMan • 2♀; 20 km W Barka, Wadi Far; 14 Mar. 2022; C. Schmid-Egger leg.; CSE • 6♂, 1♀; Dhaufur, Thumrait 35 km N, KF desert farm; 21 Sep. 2023; C. Schmid-Egger & W-H. Liebig leg.; CSE/ TJWC/WHLC • 1♂; Dhofar, 2 km W Taqah; 29 Aug. 2019; Figure 11. Thyreus parthenope Lieftinck, 1968, female. A. Habitus, lateral view; B. Head, frontal view; C. Vertex, dorsal view; D. Scutum, dorsal view; E. Scutellum, dorsal view; F. Metasoma, dorsal view. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species276 C. Schmid-Egger leg.; CSE • 1♀; Dhofar, 35 km N Thumrait, Najd; 3 Sep. 2019; C. Schmid-Egger leg.; CSE • 1♀; SW of Sur; 3–5 Mar. 2017; M. Snižek leg.; OÖLM; Qatar • 1♂; Al Shahaniyeh [Ash-Shahaniyah]; 9 May 1980; C.G. Roche leg.; D.B. Baker det. 1993; OUMNH • 1♂; Al Shahaniyeh [Ash-Shahaniyah]; 23 May 1980; C.G. Roche leg.; D.B. Baker det. 1993; OUMNH • 5♂; Al Shahaniyeh [Ash-Shahaniyah]; 13 Jun. 1980; C.G. Roche leg.; D.B. Baker det. 1993; OUMNH; United arab eMirates • 1♀; Wadi Bih, dam; 29 Nov. 2009; A. van Harten leg.; CSE. Thyreus picaron Lieftinck, 1968 Thyreus picaron Lieftinck, 1968: 92, ♂ [Croatia, RMNH, examined]. Material examined. albania • 1♂; Topovë; 13 Jul. 2017; K. Janssen leg.; KJCB; bUlgaria • 1♂; Melnik; 4 Jul. 2019; M. Halada leg.; OÖLM; croatia • 1♂; Stobreč (nr. Split); 13 Jun. 1962; C. v. Heijningen leg.; M.A. Lieftinck det.; RMNH; RMNH.INS.1714262 (holotype) • 1♂; Baška, Insel Krk; 16 Aug. 1976; J. Heinrich leg.; OÖLM; cyprUs • 1♂; 20 km NNW Pafos, Lara Beach; 20 Jun. 2013; C. Schmid-Egger leg.; CSE • 1♂; Akrotiri; 26 Apr. 2018; A. Varnava leg.; TJWC; france • 1♂; Alpes Maritimes, 1 km S Fontan; 13 Jul. 2009; C. Schmid-Egger leg.; CSE • 1♂; Var, Le Trayas; O.W. Richards leg.; M.A. Lieftinck det.; NHMUK; georgia • 1♂; Tbilissi, Botanical Garden; 26 Jul. 2021; V. Leclercq leg.; E. Dufrêne det., VLC; greece • 1♂; Chalkidiki, W of Nikiti; 12–14 Jun. 2013; M. Snižek leg.; OÖLM • 1♂; Karpenission, 2000 ft [Karpenisi]; 20 Jul. 1976; K.M. Guichard leg.; M.A. Lieftinck det.; NHMUK • 1♂; Preveza env.; 25 Jun. 1997; K. Deneš leg.; OÖLM; iran • 1♂; Golestan, Kashidar; 1381 m a.s.l.; 9 Jul. 2018; W-H. Liebig leg.; WHLC • 1♂; Semnan province, Shahmirzad, 13 km NW; 1836 m a.s.l.; 7 Jul. 2022; C. Schmid-Egger leg.; CSE • 1♂; Teheran province, Elburz, Serkheh [Sorkheh Zamin]; 2266 m a.s.l.; 6 Jul. 2022; C. Schmid-Egger leg.; CSE • 1♀; Tehran prov., Elburz, Firuzkuh 1 km SW; 6 Jul. 2022; C. Schmid-Egger leg.; CSE; italy • 1♂; S-Tirol, Meran, Schloss-Trauttmansdorf; 21 Aug. 2013; T. Kopf leg.; CSE • 1♂; S-Tirol, Meran, Schloss-Trauttmansdorf; 11 Aug. 2013; T. Kopf leg.; CSE; lebanon • 1♂; Nord Libanon, Becharre [Bsharri]; 1400 m a.s.l.; 1–4 Jul. 1931; Zerny leg.; M.A. Lieftinck det.; RMNH; RMNH.INS.1714263; Montenegro • 1♂; Ulcinj; 29 Jun. 1969; Hoffer leg.; OÖLM; north Macedonia • 1♂; Suvodol, 18 km ENE of Bitola; 750–1000 m a.s.l.; 30 Jul. 1965; M.A. Lieftinck det.; RMNH; RMNH.INS.1714264; roMania • 1♂; Dobrogea [remaining text illegible]; 7 Jul. 1994; OÖLM; slovaKia • 1♂; Sturovo [Štúrovo]; 28 Jul. 1972; M. Kocourek leg.; OÖLM; spain • 1♂; Catalonia, Palamos; 19 Jul. 1959; S.G. Bishoff leg.; M.A. Lieftinck det.; ZMHB • 1♂; N. of Madrid, Rio Guadarrama; 27 Jul. 1980; K.M. Guichard leg.; NHMUK • 1♂; Segovia, Brieva, 5 km N, Las Cañones de los rios Piron y Viego; 16 Jul. 2021; T.J. Wood leg.; TJWC • 1♂; Valencia; [undated]; Moroder leg.; MNCN • 1♂; Pontevedra, Cortellas; [undated]; Varela leg.; MNCN; tUrKey • 1♂; Bitlis, Nemrut Dağı; 2300 m a.s.l.; 15 Aug. 1991; J. Halada leg.; OÖLM; UKraine • 1♂; Odessa [Odesa] Oblast, Krasnosilka env.; 23 Jun. 2024; A.V. Gontarenko leg.; E. Dufrêne det., VLC. Remarks. It was possible to identify the female of T. picaron through DNA barcoding. Unfortunately, the located female from Iran (WPATW1024-23) appears to be completely identical to T. histrionicus (Panzer, 1806). It therefore does not currently seem possible to provide a diagnosis for the female sex, and so future records of T. histrionicus from within the expanded distributional range (relative to Lieftinck 1968) of T. picaron must be considered in a broad sense. Examination of additional material has increased the distributional range of T. picaron, particularly in south-eastern Europe (Fig. 12). As suggested by Gaspar et al. (2025), the host is likely to be one or both of two of the larger Amegilla sensu stricto, either Am. (Amegilla) garrula (Rossi, 1790) or Am. (Amegilla) ochroleuca (Pérez, 1879). Like these two possible Figure 12. Distribution of Thyreus picaron Lieftinck, 1968 (red circles) along with its two suspected hosts, Amegilla garrula (Rossi, 1790) (open blue triangles) and Amegilla ochroleuca (Pérez, 1879) (filled yellow squares). Distributional data are not comprehensive. 30N 35N 40N 45N 50N 10W 010E20E30E40E50 E6 0 E Longitude Latitude Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 277 hosts, T. picaron does not extend into North Africa. Records of Am. garrula and Am. ochroleuca are presented in Suppl. material 1. The use of two hosts is suspected due to areas where only one possible host is known (with a high degree of confidence) to be present, such as in central Spain and northern Portugal (Am. garrula absent) and northernmost Italy (Am. ochroleuca absent). At the Italian sites surveyed in 2013, T. picaron was flying with Am. garrula, supporting this association. Thyreus picaron has also been regularly collected with Am. garrula in the south of France (M. Aubert, pers. comm.). Based on this hypothesis, T. picaron should be common in Turkey; a study of additional Turkish Thyreus specimens to clarify its range in this country is necessary. It is important to note that there is a cryptic species close to Am. ochroleuca which is currently being described from Lebanon, eastern Turkey (Ağrı, Hakkâri), northern Iran, and south-western Turkmenistan (P. Rasmont & TJW, in preparation); it is very rare in collections and is collected much more rarely than Am. ochroleuca in Turkey. It may serve as a third host species for T. picaron. For simplicity, these records are here folded into Am. ochroleuca. In northern Iran, T. picaron, the cryptic “Am. ochroleuca”, and Am. garrula have all been caught in close proximity (Fig. 12). We report T. picaron as new for the fauna of Ukraine, from where Am. ochroleuca has also been recorded (see Suppl. material 1), and this species is also known from the Odesa region based on specimens held in the Kansas collection and determined by Brooks (KSEM1323579; Ascher and Pickering 2025), providing a plausible host. We also report T. picaron as new for Georgia, at a collecting locality where several Am. garrula were also captured (see Suppl. material 1). Distribution. Portugal, Spain, France, Italy, Austria, Slovakia*, Slovenia, Croatia, Serbia, Romania, Ukraine*, Montenegro*, Albania*, North Macedonia, Bulgaria, Greece, Cyprus, Turkey, Georgia*, Lebanon*, Iran (Lieftinck 1968 partim; Kuhlmann et al. 2014; Varnava et al. 2020; Ascher and Pickering 2025; Gaspar et al. 2025; Fig. 12). As discussed above, we suspect that records from Central Asia will correspond to T. jansseni. Thyreus priesneri Lieftinck, 1968 Thyreus priesneri Lieftinck, 1968: 124, ♂ [Egypt, type location unclear]. Material examined. saUdi arabia • 1♂, 1♀; Abu Arish; 25 Mar. 1980; K.M. Guichard leg.; D.B. Baker det. 1981; NHMUK. Notes. Lieftinck (1968) described T. priesneri from a single male specimen collected from southern Egypt (Gebel Elba). This specimen was cited as being in the collection of Hermann Priesner at “Linz”, but it could not be located there, and its current deposition is therefore not immediately clear; further study is required to trace it. Fortunately, the description is well illustrated, allowing confident recognition. In the NHMUK collection, two specimens from Saudi Arabia were found; as with T. parthenope, these specimens were identified by Baker but were never published. The male clearly matches the criteria identified by Lieftinck, and due to co-occurrence and close morphology, the female can now be recognised (Fig. 13). The female can be diagnosed based on a combination of characters, but care must be taken, as they are quite subtle. The clearest confusion is with Thyreus fallibilis (Kohl, 1905), which was described from southern Yemen (Fig. 14). Lieftinck (1968) diagnosed this species and described the unknown male; due to the similarity of the females, this species is diagnosed last. Diagnosis. As in T. parthenope, T. priesneri has an unbroken line of white hairs running along the entire length of the lateral margins of the scutum (Fig. 13E), as in T. ramosus (Lepeletier, 1841) and T. ramosellus Cockerell, 1919. Thyreus parthenope is diagnosed above, displaying white hair patches on the axillae and scutellum, whereas these areas are black-haired in T. priesneri (Fig. 13E), which also shows the lower half of the mesepisternum with large shining interspaces (Fig. 13D; with some interspaces reaching 3 puncture diameters), whereas in T. parthenope this area is densely punctate, without large shining interspaces. This shining and sparsely punctate mesepisternum also allows separation from T. ramosus and T. ramosellus, and indeed it is strange that Lieftinck diagnosed T. priesneri against T. ramosus when in the construction of the genital capsule and the shining lower half of the mesepisternum it is much closer to T. hyalinatus (Vachal, 1903), with which it has an overlapping range in Egypt and the Arabian Peninsula. Thyreus priesneri can be differentiated from the latter species due to the axillae with black hairs (Fig. 13E; in T. hyalinatus with white patches of hairs covering the axillae), the L-shaped patches of hairs on the lateral parts of T1 (Fig. 13F), these being uneven, with the apical part projecting further towards the centre of the tergal disc than the basal part (in T. hyalinatus with the C-shaped patches of hairs more even, with both the basal and apical parts uniformly projecting towards the centre of the tergal disc), and the posterior margin of the scutellum, which has posteriorly projecting white hairs emerging from below but not sitting on the dorsal side of the disc (Fig. 13E; in T. hyalinatus with hairs emerging both from below the posterior margin of the scutellum and present on the dorsal side of the posterior margin of the disc). This combination of characters (continuous line of white hairs on the lateral margins of the scutum, lower half of the mesepisternum sparsely punctate with large shining interspaces, and axillae and scutellum entirely black-haired) should allow recognition of females of T. priesneri compared to other species in north-eastern Africa and the Arabian Peninsula. For diagnosis against T. fallibilis, the overall pubescence pattern is highly similar, as well as the punctation and microsculpture of the integument, such as in the lower part of the mesepisternum with large shining interspaces (Fig. 14D), the vertex domed in frontal view (Fig. 14C), and the scutellum of similar shape and with dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species278 similar puncture density (Fig. 14E). The key difference is in the structure of the individual hairs; in T. fallibilis, the hairs are flattened and strongly plumose, with the branches spreading laterally, becoming almost scale-like (Fig. 14E, F). In T. priesneri, the hairs are plumose but are not flattened, and the branches do not spread laterally, meaning that they have a more quill-like appearance (Fig. 13E, F). This can be seen most clearly on the disc of T1. As noted by Lieftinck (1968: 96), the pubescence of T. fallibilis is also slightly tinted with blue, whereas in T. priesneri the pubescence is pure white. We maintain the species concepts presented by Lieftinck, but this putative species pair would benefit from molecular investigation. Description. Female. Body length: 9 mm (Fig. 13A). Head: Dark, 1.2 times wider than long (Fig. 13B). Clypeus slightly elevated, more or less flattened across disc, densely punctate, punctures separated by ≤ 0.5 puncture diameters, interspaces shining. Labrum broadly rounded rectangular, lateral margins converging, apex thus narrower than base, labrum only slightly longer than basal width. Labrum basally with two slightly raised tubercules, medially with impressed furrow, this terminating Figure 13. Thyreus priesneri Lieftinck, 1968, female. A. Habitus, lateral view; B. Head, frontal view; C. Labrum, ventral view; D. Mesepisternum, ventrolateral view; E. Scutum, dorsal view; F. Metasoma, dorsal view. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 279 subapically at strong transverse carinae, medially produced into pointed tooth (Fig. 13C). Gena much narrower than width of compound eye, posteriorly with strongly raised winged carinae, narrowing to be almost imperceptible along posterior margin of vertex; ocelloccipital distance 1.5 times diameter of lateral ocellus. Face between antennal insertions with weakly raised longitudinal carina, not strongly extending dorsally. Frons densely punctate, punctures separated by 0.5–1 puncture diameters, with slight impunctate space adjacent to lateral ocelli, space subequal to diameter of lateral ocellus. Head almost entirely white-haired, with brownish hairs restricted to mandibles. Antenna dark, measured along ventral surface A3, slightly but distinctly shorter than A4. Mesosoma: Scutum and scutellum densely punctate, punctures somewhat irregular, separated by < 0.5–1 puncture diameters, punctures most consistently dense on scutellum, surface shiny. Scutum with contrasting black and white pubescence, abundant white pubescence along anterior margin, lateral margins, medially with longitudinal line covering anterior ½ of segment, anterio-laterally with two white spots, postero-laterally with two thick patches Figure 14. Thyreus fallibilis (Kohl, 1905) holotype female. A. Label details; B. Habitus, lateral view; C. Face, frontal view; D. Mesepisternum, lateral view; E. Scutum, dorsolateral view; F. Metasoma, dorsal view. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species280 along posterior margin (Fig. 13E). Axillae and scutellum entirely black haired on dorsal surface. Scutellum produced into two posteriorly projecting points, between these with shallow emargination, scutellum itself relatively long, maximum width 1.5 times longer than maximum length (measured from base to midpoint between posterior points); emargination between posterior points with thick broad tuft of white hairs emerging from ventral surface. Mesepisternum in dorsal ½ covered with dense patch of adpressed white hairs, entirely obscuring surface; in ventral ½ with surface lacking hairs, with split punctation; in anterior portion with surface abundantly punctate, punctures separated by < 0.5–1, in posterior portion with punctures becoming very sparse, punctures separated by 1–4 puncture diameters, interspaces smooth and polished (Fig. 13D). Legs dark, outer surface of tibiae covered with dense felt-like white hairs, mid and hind tibiae with short dark spines projecting through pubescence. Forewing with varied colouration, predominantly hyaline with infuscation adjacent to vein, within submarginal and marginal cells, and on apical papillate region. Metasoma: Terga dark, tergal discs densely punctate with hair-bearing punctures, punctures presenting short, posteriorly projecting black plumose hairs, punctures separated by 0.5–2 puncture diameters, extending onto majority of marginal areas, with marginal areas narrowly impunctate along apical rim (Fig. 13F). T1 laterally with large patch of white hairs, these not typically C-shaped, more L-shaped with apical part projecting further towards centre of disc than basal part. T2 with broad L-shaped patch of white hairs, T3–5 with rectangular white hair patches, hair patches on all terga broadly separated medially, never complete. Pygidial plate long, triangular, narrowly rounded, lateral margins slightly raised, surface flat, irregularly punctate with punctures of variable sizes, surface very obscurely shining. Distribution. Southern Egypt and Saudi Arabia* (Lieftinck 1968). Other material examined. (Thyreus fallibilis (Kohl, 1905)) yeMen • 1♀; Makalla [Al Mukalla]; 1–30 Apr. 1899; O. Simony leg.; NHMW (holotype). New distributional data and range clarifications Thyreus hellenicus Lieftinck, 1968 Thyreus hellenicus Lieftinck, 1968: 71, ♀♂ [Greece, RMNH, examined] (Fig. 15A–D). Material examined. greece • 1♂; Parnass[us]; 19 Jul. 1956; Bytinski-Salz leg.; M.A. Lieftinck det.; RMNH; RMNH.INS.1714335 (holotype) • 1♂; Parnass[us]; 19 Jul. 1956; Bytinski-Salz leg.; M.A. Lieftinck det.; RMNH; RMNH.INS.1662710 (paratype) • 1♀; Graecia, Peloponnesus, Alt-Korinth; 3 Jun. 1964; M. Schwarz leg.; M.A. Lieftinck det.; RMNH; RMNH.INS.1662711 (paratype) • 1♀; I. Kalymnos, Pothia; 2–4 Jun. 1935; O. Wettstein; NHMW • 1♂; Legrena; 1 Jun. 1965; K.V. Krombein leg.; M.A. Lieftinck det.; RMNH; RMNH. INS.1662712 (paratype) • 3♀; Amorgos, Agioi Saranta; 1 m a.s.l.; 19 Jun. 2023; V. Leclercq leg.; V. Leclercq det.; VLC/EDC • 1♂; Gythion [Gytheio]; 3 Jun. 1937; F. Werner leg.; NHMW (paratype); KazaKhstan • 2♂; Uralsk; M. Bartel leg.; NHMW (paratypes); spain • 1♂; Madrid [no further information]; G. Mercet collection; MNCN; MNCN_Ent 436609; (paratype); syria • 1♂; S. Syria: Mount Hermon; 30 Jul. 1945; G.H. Q. & M.E.F. leg.; M.A. Lieftinck det.; NHMUK (paratype); tUrKey • 1♂; Cankiri, 15 kms Ilgaz-Cankiri Rd.; 1400 m a.s.l.; 23 Jul. 1962; Guichard & Harvey leg.; M.A. Lieftinck det.; NHMUK (paratype) • 1♂; Cankiri, 15 kms Ilgaz-Cankiri Rd.; 1400 m a.s.l.; 23 Jul. 1962; Guichard & Harvey leg.; M.A. Lieftinck det.; RMNH; RMNH.INS.1714265 (paratype) • 1♂, 1♀; Konya, Sultan Dağları, 10 km S of Çay; 1300 m a.s.l.; 18–25 Jul. 1980; H. v. Oorschot leg.; RMNH; ZMA.INS.5144951. Notes. Thyreus hellenicus is a poorly known species most commonly encountered in the East Mediterranean. Lieftinck (1968: 76) imprecisely stated “the Whole Mediterranean region” when discussing the distribution, despite presenting specimens from only Spain, Greece, Turkey, Syria, and north-western Kazakhstan (the southern tip of the Ural Mountains). Discussion of the range of this species combined with its host is necessary. Thyreus hellenicus was described from Mount Parnassus in southern Greece, and most specimen records presented by Lieftinck were from this country. Specimens from Greece, Turkey, and Syria (Mount Hermon) are morphologically consistent and recognisable (see characters in the identification key below). It was possible to examine the paratype from Spain (MNCN) from the collection of Ricardo García Mercet (Fig. 16). It has been dissected and is indeed T. hellenicus based on the size and genital capsule (Fig. 16D), as indicated by Lieftinck. The presence of this species in Spain remains perplexing, but we suggest that it may be plausible with some caveats (see below concerning host use). The two specimens from Uralsk (NHMW) are morphologically consistent with T. hellenicus; they were not actually labelled as T. hellenicus by Lieftinck and bore labels of “Thyreus praevalens det. M.A. Lieftinck” with no date, but they are clearly the specimens to which he was referring in his 1968 publication. Paratype labels have been added. The presence of T. hellenicus in western Kazakhstan is possible if broad host use of Anthophora bees of the subgenus Paramegilla Friese, 1897, is the life-history choice of this parasite (see below). Finally, we believe that Lieftinck’s comments that T. hellenicus could be present in Romania (based on the genital illustrations of T. histrionicus presented by Iuga 1958: 214) are unjustified. The genital capsule illustrated by Iuga has the gonostylus small, slender, and sparsely haired, suggesting a member of the scutellaris-group. We therefore consider the presence of T. hellenicus in Romania to be implausible based on the currently available evidence, including revision of Thyreus material from northern Greece and Bulgaria. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 281 Figure 15. Thyreus hellenicus Lieftinck, 1968 holotype male (RMNH). A. Label details; B. Habitus, lateral view; C. Face, frontal view; D. Metasoma, dorsal view; Paratype male (RMNH); E. Genital capsule, dorsal view; F. Genital capsule, lateral view. In addition, based on new observations on the island of Amorgos, we can demonstrate that at least one of the hosts of T. hellenicus is Anthophora (Paramegilla) superans Walker, 1871. On 19 June 2023, in a bare, sandy area of the preserved beach of Agioi Saranta on the island of Amorgos, Greece, one of us (VL) observed three females of T. hellenicus flying in and out of nests located in the ground, with simultaneous visitation of the same nests by Anthophora females, specifically Anthophora (Paramegilla) superans. Moreover, An. superans was the only large anthophorine bee of the same size as T. hellenicus present at the collecting event (and possibly even on the island of Amorgos) at this time. Further support for this association is the paratype of T. hellenicus collected by Max Schwarz at Corinth on 3 June 1964; he also collected a long series of An. superans at the same moment (specimens OÖLM/TJWC; see Suppl. material 1). The same can be said for the paratype from Gytheio on 3 June 1937 (NHMW), which was also collected with several An. superans (specimens NHMW). The name of the Anthophora host requires explanation, as this name has not previously been used for the dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species282 European fauna. The presence of a large Paramegilla species in southern and Aegean Greece has been known for a long time; Dours (1869: 120) used the name Anthophora dubia Eversmann, 1852, giving a distribution of “Îles de l’Archipel grec, montagnes de l’Oural, province d’Orenbourg, d’après Eversman”. The identity of An. dubia is currently being dealt with elsewhere (Rasmont et al., in review), but in short, An. dubia was described from Orenburg in southern European Russia and comprises a mixed type series (males and females incorrectly associated). Neither taxon within this type series is conspecific with the Greek bee, which is an East Mediterranean species. Searches were therefore made for the appropriate name to apply to this large and conspicuous Anthophora species. Examination of type material has concluded that the oldest names that can be applied are either Anthophora (Paramegilla) inclyta Walker, 1871, or Anthophora (Paramegilla) superans Walker, 1871. These two names come from Walker’s (1871) work on Hymenoptera collected around the Red Sea in Egypt, Arabia, and Eritrea. Francis Walker (1809–1874) was a prolific worker who has been much criticised for his abundant and superficial descriptions; the lack of respect for the work of Walker by his contemporaries was clear at the time (see the 1874 obituary cited in Evenhuis 2008), a sentiment echoed by Baker (1993: 300), who commented on the case of An. inclyta and An. superans. Much of the material described in Walker (1871) has been lost (e.g. see Monks et al. 2024), but some specimens of An. inclyta and An. superans were preserved in the collection of Frederick Smith and are now held in the NHMUK (Baker 1993; see Other material examined, below). Walker (1871: 58, no. 287) described An. inclyta in the female sex from “Rafla, Wady Ferran, Mount Sinai”. This corresponds to Arafali/Irafayle in Eritrea, Wadi Feiran in Sinai, and Mount Sinai in the southern part of the Sinai Peninsula. He then (Walker 1871: 58, no. 288) described An. superans in the “female” sex from Mount Sinai only. In the NHMUK collection, there are 3♀ of An. inclyta and 4♂ of An. superans. Although Walker wrote “female” for An. superans, he described the head as “Head, excepting the vertex white and without hairs”, suggesting a male, since the males have the clypeus, supraclypeal area, and lower paraocular areas with the integument yellow-white (Fig. 17C). It is therefore considered that An. superans was described from the male sex. A dissected male was labelled as “lectotype” by Baker in 1979 and by Brooks in 1983 (Fig. 17A), but neither of these designations was published. Although Baker (1993) wrote that it was designated as such, this was published in his PhD thesis, which does not meet the ICZN (1999) criteria for a valid Figure 16. Thyreus hellenicus Lieftinck, 1968 paratype male (MNCN). A. Label details; B. Profile; C. Metasoma, dorsal view; D. Genital capsule, dorsal view. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 283 publication. Under Articles 8 and 9, as the thesis was not a formally published work and only seven hard copies were produced, and these limited numbers were not obtainable either for free or for a charge, it fails Articles 8.1.2 and 8.1.3. This specimen from the Convent Garden on Mount Sinai (Saint Catherine’s Monastery; 28.55°N, 33.98°E) is therefore finally published here as the lectotype of An. superans, by present designation. It is conspecific with the material from Greece based on the hind basitarsi, which have a rounded bump apically (Fig. 17D; no tooth or teeth), and based on the ventro-lateral projection of the gonocoxa, which is reduced (Fig. 17F; lectotype specimen with the genital capsule fixed in a capsule with a glycerine-like substance). This reduction in the lateral projection of the gonostylus allows separation from the West Mediterranean Anthophora (Paramegilla) ferruginea Lepeletier, 1841 (compare Fig. 18E, F). Indeed, the genital capsule is so similar (Fig. 18C, D) that Lieftinck treated material (RMNH) from the East Mediterranean as An. ferruginea ssp. dubia; these specimens have been re-determined (see Figure 17. Anthophora (Paramegilla) superans Walker, 1871 lectotype male (NHMUK). A. Label details; B. Habitus, lateral view; C. Head, frontal view; D. Hind leg, lateral view; E. Metasoma, dorsal view; F. Genital capsule, inverted along the transverse plane, lateral view. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species290 Based on the newly examined specimens, we hypothesise a possible host through examination of concurrently active and captured Anthophorinae. At Bajanaul (2008) and at Lake Baikal (2011), T. scutellaris was captured with Anthophora (Mystacanthophora) meridionalis Fedchenko, 1875, by W-H. Liebig (specimens WHLC). Active at most capture sites in Kazakhstan (2024) were numerous species of Anthophora (Paramegilla) Friese, 1897, though these seem less likely to be hosts due to (i) their large size relative to T. scutellaris and (ii) their thermophilic tendencies, with most Paramegilla species favouring warm to hot grasslands and not extending into cooler parts of Siberia where T. scutellaris is also present. Clearly, additional focused study is required, but this circumstantial evidence forms the basis for a testable hypothesis. Lieftinck (1968) redefined the global range as predominantly Asian. In Europe, outside of European Russia, there is a single record from Croatia from 1886 (Lieftinck 1968); to our knowledge, the next nearest records come from Turkey and Russia (Astrakhan). Lieftinck’s records from Egypt, “Syria”, and Arabia are difficult to understand for biogeographical reasons. Most records of T. scutellaris, including the original terra typica, come Figure 24. Thyreus praevalens (Kohl, 1905) male holotype (NHMW). A. Label details; B. Habitus, lateral view; C. Head, frontal view; D. Head, lateral view; E. Scutum, dorsolateral view; F. Metasoma, dorsal view. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 291 from areas with a strongly continental climate, including cold winters. Molecular characterisation, along with additional study of Near Eastern specimens, is necessary to more fully understand the southern range limit of this species as well as its potential host(s). Distribution. ?Egypt, ?Syria sensu lato, ?Arabia sensu lato, Croatia, Russia (European part, Urals, Western Siberia, Eastern Siberia), Turkey, Iran, Turkmenistan, Kazakhstan, Afghanistan, Mongolia, China (Gansu, Inner Mongolia) (Lieftinck 1959b, 1968). Identification key for European Thyreus species The key of Lieftinck (1968) contains good information in large part but is challenging to use due to the broad geographic scope (from North Africa to China and the Korean Peninsula), the use of too many characters of variable importance, and most of all, the inclusion of males and females in the same key. This limits the ability of the user to swiftly recognise species groups, such as the scutellaris-group, based on the male genitalia, resulting in related species being scattered across widely separated parts of the key. The following key aims to extract the most salient information from Lieftinck (1968) within a narrower geographic scope, specifically that of Europe. Distributional information in the key refers only to the European range, and the broader work of Lieftinck (1968) should be consulted for non-European distributions. For males, it is strongly advised to extract the genital capsule (all species) and to examine the lobes of the 8th sterna (certain species). Despite the use of genitalia characters by de Beaumont (1940), some previous keys (e.g. Vergés 1967; Amiet et al. 2007) have not referred to the male genital capsule at all, which presents difficulties for Thyreus given the high level of difficulty rendered by a reliance on external morphology. Additional non-genital characters are given in the male key, but their use in isolation may lead to incorrect identifications. In addition to the images presented here, good illustrations and additional characters and perspectives can be found in de Beaumont (1940), Lieftinck (1968), Schwarz (1993), and Amiet et al. (2007). Female specimens are inherently more difficult to identify, and abraded specimens are often impossible; confidently determined or barcoded reference specimens should be consulted whenever possible. 1 Six visible terga, 12 antennomeres; females....................................................................................................... 2 – Seven visible terga, 13 antennomeres; males ................................................................................................... 13 2 (1) Body predominantly covered in dense adpressed white pubescence that obscures the underlying surface, in dorsal view approximately 75% of tergal surfaces covered in such pubescence (Fig. 25A). Scutellum posteriorly produced into two very long acute points, these forming a deep U-shaped emargination (Fig. 25B). Outer margins of axillae slightly detached from outer margin of scutellum, forming moderately acute points. Found only on Cyprus .......... ............................................................................................................................................T. elegans (Morawitz) – Body with white pubescence, but never covering a majority of the surface, terga always predominantly dark. Scutellum posteriorly produced into blunt or rounded points, or if produced into acute points then with the median emargination much shallower (Fig. 25D). Outer margins of axillae either flush with outer margin of scutellum (e.g. Fig. 25F) or forming small sharp points (e.g. Fig. 25D). Found on Cyprus or not ................................................. 3 3 (2) T1 with four distinct and elongate white hair patches, two placed basally and two apically, forming widely interrupted basal and apical hairbands; bands clearly separated (interrupted) by black hairs on lateral margins (Fig. 25C, E) ...................................................................................................................................................... 4 – T1 with two distinct white hair patches placed laterally (Fig. 27A, B), these either C-shaped or L-shaped, widely interrupted medially in the centre of the disc; always with continuous white hairs on the lateral parts of the disc (uninterrupted).................................................................................................................................................. 5 4 (3) Posterior margin of scutellum distinctly impressed medially, disc of scutellum thus not flattened, distinctly biconvex (Fig. 25D). Scutellum posteriorly produced into sharp acute points. Outer margins of axillae slightly detached from outer margin of scutellum, forming small sharp points. Rare in Europe, known as far west as Croatia, probably persisting mostly in European Russia .......................................................................... T. scutellaris (Fabricius) – Scutellum evenly flattened, posterior margin of scutellum not depressed medially (Fig. 25F). Scutellum posteriorly produced into blunt 90° points. Outer margin of axillae flush with outer margin of scutellum, not produced into a point. Widespread across southern Europe from Portugal to Bulgaria, Greece, and Cyprus, north to the Pannonian basin ..................................................................................................................... T. affinis (Morawitz) 5 (3) Scutum laterally with a continuous band of short white hairs running up to the junction with the axillae (Fig. 26A) Small, always < 10 mm in length ........................................................................................T. ramosus (Lepeletier) – Scutum laterally never with an unbroken band of white hairs, always with some black hairs (Fig. 26B). Larger, usually > 10 mm in length, though some small specimens of T. truncatus can be 9 mm in length ....................... 6 6 (5) Found on the island of Gran Canaria (Canary Islands) ....................................................................................... 71 – Found elsewhere in Europe, including other Canarian islands ............................................................................. 8 1 Due to the restricted geographic distribution, T. hohmanni is keyed out here; most workers will never encounter this species. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species292 7 (6) Face with abundant short black pubescence below the antennal insertions. T1, when viewed dorsally with narrow L-shaped white hair patches laterally, these barely extending towards the centre of the disc at its base. Scutellum densely punctate, punctures separated by ≤ 0.5 puncture diameters ..................................... T. hohmanni Schwarz – Face entirely white-haired. T1, when viewed dorsally with broad C-shaped white hair patches laterally, these extending inwards towards the centre of the disc almost as much at the base of the disc as on the marginal area (Fig. 27A). Scutellum more sparsely punctate with punctures separated by 0.5–1 puncture diameters, interspaces polished and shining ...............................................................................................T. histrionicus (Illiger) (partim) 8 (6) Found in Greece with the following combination of characters: scutellum short and broad, medially with a narrow but deep sulcate impression, surface densely punctate, punctures separated by ≤ 0.5 puncture diameters (Fig. 23C). Vertex behind ocellar triangle densely punctate, punctures separated by 0.5 puncture diameters, strongly contrasting areas adjacent to lateral ocelli, which are polished, shining, and almost impunctate (Fig. 23E). T1 viewed dorsally with small triangular hair patches, these barely extending towards the base of the tergum (Fig. 23D). Antenna with rhinaria elongate lanceolate, longitudinally-orientated, and placed on the ventral surface of the antenna. Face below antennal insertions with abundant dark pubescence (Fig. 23B) .............. T. praevalens (Kohl)2 – Distribution or combination of characters not as above ..................................................................................... 93 9 (8) Face below antennal insertions usually with abundant black hairs (Fig. 26C), but some specimens of T. orbatus from southern Spain (Sierra Nevada) present faces with abundant white pubescence and only a few scattered black hairs. For T. orbatus, if in doubt, then lateral white hair patch of T3 interrupted (Fig. 26D), distinctly interrupted by black hairs and thus forming two distinctly separated white hair patches ......................................................... 10 – Face below antennal insertions always white-haired (Fig. 26E), either entirely white-haired or at most with only a few scattered black hairs. Lateral white hair patch of T3 always entire, never broken into two distinct white hair patches ........................................................................................................................................................... 11 10 (9) Lateral white hair patch of T3 interrupted, distinctly interrupted by black hairs and thus forming two distinct white hair patches (Fig. 26D). Usually a little smaller, range 8–10 mm. Associated with Anthophora quadrimaculata. The most northerly Thyreus species, extending from the mountains of southern Europe into the Low Countries and northern Germany, as well as east to the Balkan Peninsula .................................................. T. orbatus (Lepeletier) – Lateral white hair patch of T3 always entire, never broken into two distinct white hair patches (Fig. 26F). Usually a little larger, range 10–12 mm. Associated with Echium-specialised Anthophora (Paramegilla) species. Restricted to the West Mediterranean north to southern Switzerland ..................................................... T. hirtus (de Beaumont) 11 (9) T1, when viewed dorsally with broad C-shaped white hair patches laterally, these extending inwards towards the centre of the disc almost as much at the base of the disc as on the marginal area (Fig. 27A). Scutellum moderately densely punctate, punctures separated by 0.5–1 puncture diameters, interspaces polished and shining (Fig. 27C) ...............................................T. histrionicus (Illiger) (partim) and picaron Lieftinck (females currently inseparable) – T1 when viewed dorsally with narrow L-shaped white hair patches laterally, these extending inwards towards the centre of the disc only on the marginal area (Figs 7F, 9F, 27B). Scutellum very densely punctate, punctures separated by ≤ 0.5 puncture diameters, interspaces weakly shining to dull (Figs 7E, 9E, 27D) ................................. 12 12 (11) Smaller species, body length range 9–12 mm. Rhinaria absent. Scutellum short and broad, surface almost flat, posterior angles blunt and poorly indicated (Figs 7E, 9E). Associated with Tetralonia dentata. Widespread across continental Europe ..................................................................................................................T. truncatus (Pérez) – Larger species, body length around 15 mm. Without rhinaria, but with a series of low longitudinal ridges. Scutellum longer, posterior angles more strongly produced (Fig. 27D). Associated with Anthophora superans. Predominantly in Greece, including the islands, but possibly also southern Spain ........................................... T. hellenicus Lieftinck 13 (1) Genital capsule simple, with gonostylus broadly triangular or produced into an acute point; never with an additional dorsal projection (Figs 2F, 28A, B). Gonostylus almost hairless, never with long hairs. T1 with hairs present basally and apically, forming either a complete basal and nearly complete apical bands (Fig. 29A) or with bands interrupted medially and separated laterally, thus appearing to form four distinct hair patches (Fig. 29B) (scutellaris-group) ...14 – Genital capsule complex, with gonostylus presenting a rounded or truncate apex (Figs 3H, 28C–H); gonostylus often with an additional basodorsal projection roughly at a 90° angle to the largest lobe of the gonostylus (Figs 3H, 28C–E). Gonostylus with long hairs, these often abundant and covering and obscuring the surface (Figs 3H, 28C–H). T1 with hairs variable, but never forming a complete basal band and always complete laterally, thus never forming four distinct hair patches .................................................................................................................... 16 2 Thyreus praevalens is keyed out here through a combination of characters; whilst it could potentially be included in the following couplet based on the dark facial pubescence, it remains unclear if this is a robust character, and so a cautious approach is taken here. 3 Separation of the following six species depends heavily on pubescence characters, which are necessarily dependent on specimen condition. No attempt should be made to try and identify strongly abraded specimens, and association with concurrently active males should be made where possible. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 293 14 (13) Body abundantly white-haired, particularly thickly covering the face (including frons), mesepisternum, and anterior ½ of scutum, obscuring the underlying surface. T1 with hairs forming a complete basal band and almost complete apical band, these bands connected laterally (Fig. 29A). T2 with broad apical hairband covering ½ the length of the tergum, only narrowly interrupted medially. Found only on Cyprus ...................................T. elegans (Morawitz) – Body without abundant white pubescence, only moderately hairy, white hairs of face, mesepisternum, and scutum not obscuring underlying integument. T1 with four distinct and elongate white hair patches, two placed basally and two apically, forming widely interrupted basal and apical hairbands (Fig. 29B). Found on Cyprus or not ......................................................................................................................................... 15 15 (14) Posterior margin of scutellum distinctly impressed medially, disc of scutellum thus not flat, distinctly biconvex (as in Fig. 4C). Scutellum posteriorly produced into sharp acute points, medially with loose thin whitish hairs on dorsal surface, these not obscuring the underlying surface. Outer margin of axillae slightly detached from outer margin of scutellum, produced into a subtle but distinct point (as in Fig. 4C). Rare in Europe, known as far west as Croatia, probably persisting mostly in European Russia ................................................................. T. scutellaris (Fabricius) – Scutellum evenly flat, posterior margin of scutellum not depressed medially. Scutellum posteriorly produced into blunt ~90° points, medially with distinct patch of adpressed thick white hairs which obscures the underlying surface (Fig. 29C; may be abraded in old specimens). Outer margin of axillae flush with outer margin of scutellum, not produced into a point. Widespread across southern Europe from Portugal to Bulgaria, Greece, and Cyprus, north to the Pannonian basin ........................................................................................................... T. affinis (Morawitz) 16 (13) In lateral view, gonostylus distinctly bifurcate, with a large apically projecting and truncate lobe and basal detached and dorsally projecting acutely pointed lobe oriented roughly 90° relative to the truncate lobe (Fig. 3H, 28C–E) 17 – In lateral view, gonostylus with only a single apically projecting lobe, never with a distinct detached dorsally projecting lobe (Fig. 28F–H) .................................................................................................................................. 20 17 (16) Apical projections of S8 slender with distinct 90° bend, thus appearing distinctly “L-shaped” (Fig. 3F) ................. ............................................................................................................................................... T. picaron Lieftinck – Apical projections of S8 parallel-sided, apexes truncate to rounded (Fig. 29D) ................................................. 18 18 (17) Face with abundant black hairs on the face below the antennal insertions. In dorsal view, lateral margins of T1 with white hairs loose, not adpressed, laterally erect and projecting thus contrasting the white hairs on the marginal area of T1 which are adpressed, obscuring the underlying surface (Fig. 29E). Restricted to the West Mediterranean north to southern Switzerland .......................................................................................... T. hirtus (de Beaumont) – Face entirely white-haired. In dorsal view, lateral margins of T1 with white hairs adpressed, not differentiated from adpressed white hairs on the marginal area of T1 (Fig. 29F). Widespread throughout Europe ........................... 19 19 (18) Genital capsule with dorsal projection strongly produced, standing distinctly away from outer margin of gonocoxa, with long hairs, length of these hairs at least twice the breadth of the dorsal projection (Fig. 28D). Main lobe of gonostylus with abundant long hairs; in lateral view, hairs projecting beyond the apex of the gonostylus by a distance equal to the maximum breadth of the hind basitarsus (Fig. 30A) .................................T. histrionicus (Illiger) – Genital capsule with dorsal projection weakly produced, not strongly isolated from outer margin of gonocoxa, with short hairs, these hairs equalling or only slightly exceeding breath of the dorsal projection (Fig. 28E). Main lobe of gonostylus with abundant but short hairs; in lateral view, hairs only slightly projecting by much less than the maximum breadth of the hind basitarsus (Fig. 30B) ................................................................T. truncatus (Pérez) 20 (16) Scutellum short and broad, medially distinctly impressed and narrowly sulcate (Fig. 24E). T1 viewed dorsally with small apicolateral triangular hair patches, not extending towards base of tergum (Fig. 24F). Vertex behind ocellar triangle densely punctate, punctures separated by 0.5 puncture diameters, strongly contrasting areas adjacent to lateral ocelli, which are polished, shining, and almost impunctate (Fig. 23F). Found only in Greece .. ......................................................................................................................................... T. praevalens (Kohl) – Scutellum flat, without such a median sulcate impression. T1 viewed dorsally with hair patches narrow or broad, but always extending to the base of the tergum. Vertex without such strongly contrasting punctation. Distribution variable ............................................................................................................................................. 21 21 (20) Face below the antennal insertions usually with abundant black hairs (cf. Fig. 26C). In well-preserved specimens, T3 laterally with white band interrupted, thus forming two distinct white hair patches (Fig. 30C). Hind tibia ventrally produced into a small but distinct sharply pointed tooth overlying outer tibial spur (difficult to see without practice). Genitalia as in Fig. 28F. The most northerly Thyreus species, extending from the mountains of southern Europe into the Low Countries and northern Germany to around 52°N .................................T. orbatus (Lepeletier) – Face below the antennal insertions never with abundant black hairs (Figs 15C, 16B). T3 laterally with a single unbroken white hairband (Figs 15B, 16B, 30D). Hind tibia without such a ventrally projecting tooth. Genitalia as in Figs 15E and 30E–F. Not extending north of 49°N ............................................................................................ 22 22 (21) Genital capsule with gonostylus long, in lateral view gonostylus elongate triangular, strongly projecting away from the gonocoxa by a distance exceeding the maximum breadth of a hind basitarsus (Fig. 15F). In dorsal view, the dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species294 long gonostyli give the genital capsule a rhomboidal appearance (Fig. 15E). Large, body length around 15 mm. Restricted to Greece, including the islands ........................................................................... T. hellenicus Lieftinck – Genital capsule more compact, gonostylus short, in lateral view gonostylus barely projecting beyond the gonocoxae. In dorsal view, genital capsule ovoid or rounded (Fig. 28G, H). Either large bodied (12–13 mm), in which case found only on the Canary Islands, or if found in continental Europe, then smaller, < 10 mm in length............... 23 23 (22) T7 with apical margin emarginate, emargination rounded rectangular, broader than deep (Fig. 30E). Smaller, body length < 10 mm. Widespread across continental Europe, but not present on the Canary Islands ........................... ..........................................................................................................................................T. ramosus (Lepeletier) – T7 with apical margin emarginate, emargination evenly rounded (Fig. 30F). Large, body length 12–13 mm. Restricted to Gran Canaria (Canary Islands) .....................................................................................T. hohmanni Schwarz Figure 25. Thyreus elegans (Morawitz, 1877) female. A. Metasoma, dorsal view; B. Scutellum, dorsal view. Thyreus scutellaris (Fabricius, 1781) female; C. T1, dorsal view; D. Scutellum, dorsal view. Thyreus affinis (Morawitz, 1873) female; E. T1, dorsal view; F. Scutellum, dorsal view. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 295 Discussion The results presented here and the taxonomic concepts refined through the inclusion of COI DNA barcoding overall support the taxonomic framework of Lieftinck (1968) for the West and Central Palaearctic species studied to date. The small number of changes necessary have related to minor errors in distributions resulting from misidentified or cryptic species, and the inclusion of genetic data and concurrent study with their predominantly anthophorine hosts has allowed range limits to be characterised with greater confidence. Although most tropical species of Thyreus are likely to exclusively attack Amegilla due to the absence of Figure 26. Thyreus ramosus (Lepeletier, 1841) female. A. Scutum, dorsolateral view. Thyreus histrionicus (Illiger, 1806) female; B. Scutum, dorsolateral view; E. Head, fronto-lateral view. Thyreus hirtus (Beaumont, 1940) female; C. Head, fronto-lateral view, F. Metasoma, lateral view. Thyreus orbatus (Lepeletier, 1841) female; D. Metasoma, lateral view. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species296 the genus Anthophora in very humid areas (for example, in most of South East Asia and all of Australasia; Brooks 1988), the pattern in the Palaearctic is much more mixed. Species known or suspected to attack Anthophora include T. hellenicus, T. hirtus, and T. orbatus; species known or suspected to attack Amegilla include T. histrionicus, T. picaron, and T. ramosus, whilst T. truncatus attacks bees of a different subfamily (Eucerinae). Thyreus elegans sensu lato is suspected to attack Amegilla (Micramegilla) Brooks, 1988 based on co-occurrence (TJW, unpublished data), and hypotheses are presented here for associations between T. jansseni and T. scutellaris with Anthophora (Mystacanthophora) species. Even in the absence of a modern phylogeny of the genus Thyreus, it is difficult to see how this would translate into a pattern of conserved host use relative to the phylogenetic structure seen in apid bees (Bossert et al. 2019). Finally, whilst generic concepts are currently under revision in melectine bees due to the generation of powerful new genetic data and morphological analyses (Onuferko et al. 2021; Orr et al. 2024), the present work serves to restate the need to robustly test species-level concepts. It also emphasises the importance of balancing molecular results with morphological criteria. Although genetic variation in the COI barcode is much higher in T. truncatus than in other Thyreus species studied here, it was not possible to find morphological criteria consistent with barcode clustering to allow for taxon delineation; hence, a conservative and broad species concept was maintained. Whilst the high barcode differences suggest a pattern of historical isolation, perhaps in an Iberian refugium for Iberian specimens, reliance purely on genetic distance would produce a challenging system for morphological identification, as well as potentially lead to nomenclatural instability depending on which mitochondrial lineage the lectotype is assigned to. This approach is consistent with other recent treatments (e.g. Praz and Benon 2023) and will hopefully maintain the fundamentally robust species concepts of Lieftinck (1968) for current and future species monitoring. Figure 27. Thyreus histrionicus (Illiger, 1806) female; A. T1, dorsal view; C. Scutellum, dorsal view. Thyreus hellenicus Lieftinck, 1968, female; B. T1, dorsal view; D. Scutellum, dorsal view. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 297 Figure 28. Thyreus elegans (Morawitz, 1877) male. A. Genital capsule, dorsal view. Thyreus affinis (Morawitz, 1873) male; B. Genital capsule, dorsal view. Thyreus hirtus (Beaumont, 1940) male; C. Genital capsule, dorsal view. Thyreus histrionicus (Illiger, 1806) male; D. Genital capsule, dorsal view. Thyreus truncatus (Pérez, 1884) male; E. Genital capsule, dorsal view. Thyreus orbatus (Lepeletier, 1841) male; F. Genital capsule, dorsal view. Thyreus hohmanni Schwarz, 1993 male; G. Genital capsule, dorsal view. Thyreus ramosus (Lepeletier, 1841) male; H. Genital capsule, dorsal view. dez.pensoft.net Thomas Wood et al.: A contribution to Thyreus in the Palaearctic, with two new species298 Figure 29. Thyreus elegans (Morawitz, 1877) male. A. T1, dorsal view. Thyreus affinis (Morawitz, 1873) male; B. T1, dorsal view. C. Scutellum, dorsal view. Thyreus hirtus (Beaumont, 1940) male; D. S8, dorsal view; E. Lateral part of T1, dorsal view. Thyreus histrionicus (Illiger, 1806) male; F. Lateral part of T1, dorsal view. Dtsch. Entomol. Z. 72 (2) 2025, 259–302 dez.pensoft.net 299 Figure 30. Thyreus histrionicus (Illiger, 1806) male. A. Genital capsule, lateral view. Thyreus truncatus (Pérez, 1884) male; B. Genital capsule, lateral view. Thyreus orbatus (Lepeletier, 1841) male; C. Metasoma, lateral view. Thyreus ramosus (Lepeletier, 1841) male; D. Metasoma, lateral view; E. T7, dorsal view. Thyreus hohmanni Schwarz, 1993 male; F. T7, dorsal view.