Paraxenos arabicus Benda & Pohl & Nakase & Beutel & Straka 2023, sp. nov.

Paraxenos arabicus Benda & Straka sp. nov. urn:lsid:zoobank.org:act: 907A30CD-396F-48AC-B798-36400112966B Figs 1–2, 4F Diagnosis Female cephalothorax Differing from P. hungaricus and P. krombeini Kifune & Hirashima, 1987 by the maxilla shaped like an orthogonal triangle; maxillary base wide; maxilla narrowing anteromedially in contrast to anteriorly in P. hungaricus and P. krombeini. Maxillary base about 3× as wide as anterior part of maxilla (mxb, mx, Fig. 2A), very slightly overlapping with mandible proximally. Mandible completely enclosed in mandibular capsule as in P. hungaricus, in contrast to P. krombeini where the mandible overtops the anterior edge of the head capsule. Mandibular base slightly bulging, separated from genal area by furrow. Labial area between maxillae slightly wider than long (lba, Fig. 2A), versus distinctly wider than long in P. hungaricus (lba, Fig. 6C). Dorsal labral field distinctly arcuate (dlf, Fig. 2A) as in P. krombeini, in contrast to slightly arcuate in P. hungaricus. Mouth opening very slightly arcuate to straight and not distinctly sclerotized around margin (os, Fig. 2A), versus conspicuously sclerotized in most specimens of P. hungaricus. Lateral extensions of head capsule dull on ventral side (lehc, Fig. 2A), covered by conspicuous and densely arranged dark papillae, cuticle wrinkled between papillae, in contrast to lateral extensions pale, shiny to dull, without densely arranged papillae in P. hungaricus. Lateral region of abdominal segment I below spiracles only slightly darker than dorsal side (asI, Fig. 1D), and not distinctly contrasting to pale thorax as in P. hungaricus. Anterior head margin distinctly protruding as in P. krombeini, versus only slightly protruding from head capsule in P. hungaricus. Male cephalotheca Paraxenos arabicus sp. nov. differs from P. hungaricus by several characters.In lateral view, cephalotheca rounded anteriorly, versus protruding and acute anteriorly in P. hungaricus. Clypeus (clypeal lobe) not projecting in lateral view (cl, Fig. 2D), but prominent in P. hungaricus. Gena around compound eye nearly completely pale (gn, Fig. 2C), with dark area around mandibular base reduced; pale stripe between compound eye and mandibular base wide, about 2× as wide as diameter of compound eye; in P. hungaricus about as long as diameter of compound eye. Maxilla not wide at base, about 1.5× as wide as mandible (mx, Figs 2C, 4F), but about 2× as wide as mandibular width in P. hungaricus. Length of clypeal lobe approximately equal to mandibular length (cll, Fig. 4F), versus clypeal lobe distinctly wider than length of mandible in P. hungaricus. Etymology The specific epithet refers to Arabia, the region of origin of the new species. Adjective. Material examined Holotype UNITED ARAB EMIRATES • ♀ (cephalothorax on mounting board); Umm al-Kuvajn, Biyatah env.; 50 m a.s.l.; 28 Feb. 2017; M. Halada leg.; host: Bembix kohli Morice, 1897; NMPC. Paratypes UNITED ARAB EMIRATES • 2 ♀♀, 3 male puparia (MP); same collection data as the for holotype; NMPC • 1 MP; Al Dhaid, Šardžá env.; 2 Mar. 2017; L. Bíca leg.; NMPC. Description Holotype (female cephalothorax) SHAPE AND COLORATION. Size of holotype cephalothorax: length 1.32 mm, width 1.68 mm. Anterior head margin distinctly protruding. Thorax slightly widening posteriorly. Cephalothorax displaying multiple light brown shades, cuticle sclerotized and darker only around mandible. Cephalothorax less pigmented medially, darker laterally. HEAD CAPSULE. Approximately ⅓ as long as entire cephalothorax including lateral extensions. Coloration pale to dark with specific pattern (Fig. 2A). Clypeal area well separated from labral area, protruding anteriorly and forming clypeal lobe. Surface slightly wrinkled on dorsal side. Lateral extensions of head capsule dull ventrally (lehc, Fig. 2A), covered by conspicuous dark papillae, with cuticle wrinkled between them. Clypeal sensilla mainly concentrated on clypeal lobe and extending to ventral side of clypeal area. Border between clypeal and frontal regions not clearly recognizable, but present. Frontal region distinctly wrinkled, without dark papillae. Segmental border between head and prothorax indistinct on dorsal side, but indicated by change in cuticular surface structure. SUPRA-ANTENNAL SENSILLARY FIELD. Slightly wrinkled, with dispersed sensilla, delimited by distinct furrow on medial side (fssf, Fig. 2B). ANTENNA. Morphology of antennal vestige not recognizable. LABRUM. Ventral field distinctly wider than long, elliptic. Dorsal field distinctly arcuate,> 4× as wide as long in midline. Dorsal field with approximately 25 setae inserted in cavities (dlf, vlf, Fig. 2A). MANDIBLE. Anteromedially directed at an angle of 30°, completely enclosed in mandibular capsule or very slightly protruding from it. Mandibular bulge not distinctly raised, with approximately 15 sensilla. Cuticle almost completely smooth, partially sculptured on articulatory area. Mandibular tooth narrow, pointed, sharply curved anteriorly. Mandibular base slightly bulging, divided by furrow from genal area (Fig. 2A). MAXILLA. Well-developed and prominent, separated from labial area. Shaped like orthogonal triangle. Very wide basally, narrowing anteriorly, maxillary base about 3× as wide as distal part (mxb, mx, Fig. 2A). Anteromedially directed, very slightly overlapping mandible. Cuticle smooth. Vestige of palp present, with more or less distinct plates, located anteriorly on ventral side of maxilla. Submaxillary groove distinctly produced posterolaterally (smxg, Fig. 2A). LABIUM. Labial area between maxillae distinct, delimited anteriorly by mouth opening and posteriorly by birth opening. Flat and slightly wider than long in midline to almost square. Cuticular surface smooth to slightly wrinkled and reticulated. MOUTH OPENING. Straight, not distinctly sclerotized along margin. THORAX. Pro-mesothoracic and meso-metathoracic borders distinct on ventral side, separated by mesal furrows (sbpm, sbmm, Fig. 1C). On dorsal side only indistinctly indicated by differing cuticular sculpture. Border between metathorax and abdomen formed by ridge in combination with changed cuticular sculpture and coloration. Cuticle of thoracic segments reticulate on ventral side, with small, scattered pigmented papillae. Prosternal extension differentiated by cuticular sculpture and coloration (pst, Fig. 2A). Anterior part darker with conspicuous pigmented papillae medially (pstp, Fig. 2A), posterior part pale and lacking distinct pigmented papillae. Meso- and metathorax unmodified in shape, transverse. Mesosternum with small paler area posteromedially, without pigmented papillae. Metasternum with large pale area medially without pigmented papillae and width reaching up to ⅔ of metathorax (Fig. 1C). Dorsal side of thorax smooth or slightly reticulated. ABDOMINAL SEGMENT I AND SPIRACLES. Lateral region of abdominal segment I below spiracles only slightly darker on dorsal side, not distinctly contrasting to pale thorax (asI, Fig. 1D). Spiracles on posterior half of cephalothorax slightly elevated, with lateral or laterodorsal orientation. VARIABILITY OF FEMALE CEPHALOTHORAX. Cephalothorax compact, nearly as long as wide or distinctly wider than long. Size slightly variable, length 1.18–1.32 mm, maximum width 1.32–1.68 mm. Dorsal labral field with about 21 to 25 setae inserted in cavities. Mandible anteromedially directed at an angle of 30–45°. Mandibular bulge not distinctly raised, with approximately 12–18 sensilla. Mouth opening very slightly arcuate to straight. Male cephalotheca SHAPE AND COLORATION. In frontal view rounded, slightly flattened, elliptic, length 0.66–0.82 mm, width 1.30–1.46 mm; in lateral view rounded anteriorly, not acute apically. Coloration predominantly pale with some dark areas forming specific pattern (Fig. 2C). CEPHALOTHECAL CAPSULE. Compound eyes pale, with darker individual cornea lenses recognizable. Gena around compound eye almost completely pale, dark area around mandibular base missing; pale area between compound eye and mandibular base about 2× as wide as diameter of compound eye (gn, coe, Fig. 2C). Clypeus pale medially and darker laterally. Clypeal lobe straight in frontal view, blunt and not prominent in lateral view. Length of clypeal lobe nearly equal to mandibular length (cll, Fig. 4F). Sensilla mainly concentrated on clypeal lobe, visible. Frontal region with paired furrow of supra-antennal sensillary field, lacking impression or clearly recognizable occipital bulge (fssf, Fig. 2C). Occipital bulge indistinct (ob, Fig. 2C). Diameter of genae between maxillary base and compound eye more than 2× as long as diameter of vestigial antenna. SUPRA-ANTENNAL SENSILLARY FIELD. Predominantly pale to partly dark (ssf, Figs 2C, 4F), kidney-shaped and bulging, delimited medially by distinct furrow. Furrows wide, not connected anteriorly. Dark sensilla distinctly visible on pale surface. ANTENNA. Of standard shape, pale or dark, small, with small plates, sensilla and complete torulus (a, Figs 2C, 4F). Periantennal area not clearly delimited from supra-antennal sensillary field, pale or dark. LABRUM. Labral area distinct. Dorsal field conspicuous, pale, with dispersed setae well visible. Ventral field darker (Fig. 2C). MANDIBLE. Nearly medially directed. Tooth apically pointed, wide basally, but not reaching area of mandibular bulge. Coloration mostly pale, especially middle region, with darker parts apically and basally. Mandibular bulge with sensilla, separated from tooth. Length between mandibles nearly equal to mandibular length. MAXILLA. Distinct, prominent, with darker and paler parts. Vestige of palp present, conspicuous (mxp, Figs 2C, 4F). Not very wide at base, approximately 1.5× as wide as mandible (mx, Figs 2C, 4F). LABIUM AND HYPOPHARYNX. Labium distinct, located between and below maxillae, darker. Praementum and postmentum more or less distinctly separated by furrow (Fig. 2C). Hypopharyngeal protuberance absent. MOUTH OPENING. Visible, not covered by ventral labral field, slightly arcuate, sclerotized around margin. Host Bembix kohli Morice, 1897. Distribution United Arab Emirates.Published as part of Benda, Daniel, Pohl, Hans, Nakase, Yuta, Beutel, Rolf & Straka, Jakub, 2023, A new species of the genus Paraxenos Saunders, 1872 (Strepsiptera: Xenidae) from Bembix digger wasps (Hymenoptera: Bembicidae) and a redescription of Paraxenos hungaricus (Székessy, 1955), pp. 134-155 in European Journal of Taxonomy 885 (1) on pages 137-142, DOI: 10.5852/ejt.2023.885.2197, http://zenodo.org/record/820538