Deltoxenos reginus Benda & Straka 2025, sp. nov.

Deltoxenos reginus Benda & Straka sp. nov. Figs 13 A – D, 14 A – D, 15 A, B Type material. Holotype • ♀ (KUNHM), Madagascar: Diego Suarez Prov., Mt. D´Ambre, Ambohitra Forest Preserve, 16.xi.1986, host: Delta regina (Saussure, 1852), J. Wenzel lgt. Diagnosis of female cephalothorax. For differentiation from D. indonesiensis, see diagnosis of the female cephalothorax of D. indonesiensis sp. nov. Area of mouthparts in front of birth opening shortened and maxillae reduced compared to D. hajeki and D. maceki. Differs from D. rueppelli by rounded and protruding clypeal lobe. Maxilla not well developed, slightly bulging, triangular, slightly separated from labial area (mx, Fig. 15 A); meso- and metathorax distinctly elongated as in D. indonesiensis. Description of female holotype cephalothorax. Shape and colouration. Size of cephalothorax: length 2.67 mm, width 2.27 mm (Fig. 13 C). Cephalothorax large, elongated, distinctly longer than wide. Pro-mesothoracic segmental border constriction indistinctly visible, meso-metathoracic segmental border conspicuously constricted laterally (sbpm, sbmm, Fig. 13 C). Abdominal segment I not protruding laterally, corner below spiracles rounded. Anterior head margin rounded, distinctly protruding from remaining head capsule. Thorax elongated, very slightly widening posteriorly. Cephalothorax with conspicuously contrasting light and dark colour pattern, predominantly dark ventrally and light dorsally. Head capsule. Length proportion of head / cephalothorax 0.34 including lateral cephalic extension. Colouration forming specific pattern with predominantly light parts and dark brown labium and slightly darker mandibles and maxillae. Surface of lateral extensions at site of reduced compound eyes smooth, laterally with only poorly visible longitudinal grooves; lateral extensions mostly light brown (lehc, Fig. 13 C). Clypeal area well delimited from labral area medially, indistinctly laterally; clypeal lobe arcuate, distinctly protruding from head capsule. Surface of clypeal area smooth to slightly wrinkled, with> 25 exposed sensilla mainly concentrated on clypeal lobe on ventral side (cls, Fig. 15 A). Dorsal side of clypeal area slightly wrinkled and lacking sensilla (cl, Fig. 15 B). Border between clypeal and frontal region slightly visible, distinguishable by inconspicuous furrow. Frontal region distinctly reticulated and wrinkled (fr, Fig. 15 B). Segmental border between head and prothorax indicated by very indistinct mesal furrow on dorsal side (sbhp, Fig. 14 B) and by distinct dark transverse stripe (visible on colour photograph, sbhp, Fig. 13 D). Head and prothorax distinctly separated by birth opening ventromedially (bo, Fig. 14 A) and laterally by suture (sbhp, Fig. 14 A). Supra - antennal sensillary field. Wrinkled to completely smooth, with dispersed sensilla inserted in indistinct cavities (sssf, Fig. 15 B). Very slightly delimited by furrow on mesal side, indistinctly recognisable by cuticular surface structure (fssf, Fig. 15 B), with supra-antennal sensillary field and frontal region with different sculpture. Antenna. Preserved as well-defined area, with several vestigial sensilla, rounded plates and inconspicuous cavities (a, Fig. 15 B). Edges of antennal area poorly defined, antennal torulus completely reduced. Periantennal area slightly expanded, smooth (paa, Fig. 15 B). Labrum. Ventral field distinctly wider than long, transversely elongated, elliptic. Dorsal field very slightly arcuate, flat, not raised, laterally not narrower than medially, 5 × wider than long in midline (vlf, dlf, Fig. 15 A). Sensilla on dorsal field very indistinctly visible. Mandible. Mandibles anteromedially directed at an angle of 30 °, enclosed in mandibular capsule. Mandibular bulge distinctly raised, directed anteriorly, blunt, not elongated; sensilla of mandibular bulge poorly visible (mdb, Fig. 15 A). Cuticle of mandible mostly wrinkled, laterally without longitudinal furrows. Mandibular tooth curved backwards, pointed posteriorly, armed with many small spines (mdt, Fig. 15 A). Maxilla. Indistinct, slightly bulging, triangular, slightly separated from labial area (mx, Fig. 15 A). Colouration dark to pale, with cuticle wrinkled, reticulated. Apical maxillary region not projecting beyond mandibular apex. Basal part connected with labium, laterally very slightly overlapping with mandible (mxb, Fig. 15 A). Vestige of palp present, located medially on ventral side of maxilla, very indistinct (mxp, Fig. 15 A). Maxillary base (mxb) distinctly produced anterolaterally as submaxillary groove. Space between prothoracic extension and head not extended (sbhp, mxb, Fig. 14 A). Labium. Labial area between maxillae quite indistinct, delimited anteriorly by mouth opening and posteriorly by birth opening (lb, Fig. 15 A). Flat, longer than wide. Cuticular surface wrinkled. Mouth opening. Very slightly arcuate, medially almost straight, sclerotised along margin (os, Fig. 15 A). Thorax. Pro-mesothoracic and meso-metathoracic borders visible ventrally as slightly to distinctly imprinted mesal furrows (sbpm, sbmm, Figs 13 C, 14 A). On dorsal side separated by conspicuous dark mesal furrows, distinctly contrasted with mostly pale thoracic segments (sbpm, sbmm, Figs 13 D, 14 B). Border between metathorax and abdomen indicated by ventral ridge on ventral side or indicated by change in colour and cuticular sculpture. Cuticle of thoracic segments on ventral side predominantly reticulated, or smooth; dark pigmented papillae on mesosternum and metasternum almost absent. Prosternum differentiated, anteriorly light brown with smooth or slightly wrinkled surface, posteriorly dark and reticulated (pst, Fig. 13 C); field of sensilla present. Mesosternum mostly dark, without spots. Metasternum predominantly dark, colour not distinctly lighter medially. All thoracic segments dorsally mostly pale, but darker laterally. Meso- and metathorax transverse, distinctly elongated. Abdominal segment I and spiracles. Setae and cuticular spines very rarely present on lateral region of abdominal segment I posterior to spiracle, cuticle mostly wrinkled (Fig. 14 D). Spiracles on posterior ~ 1 / 3 of cephalothorax, very slightly elevated, with lateral or dorsolateral orientation. Cephalothoracic part of abdominal segment I below spiracles dark brown on both sides (asI, Fig. 13 D). Host. Delta regina (Saussure, 1852). Phylogenetic relationships. Unknown. Distribution. Madagascar. Etymology. From the Latin substantive regina, meaning queen. The specific epithet reginus refers to the host species name. Adjective. Comments. Salt (1927) reported stylopised Delta regina (as Eumenes maxillosus (Degeer) var. reginus (Saussure)) from the same locality as the holotype (Fig. 17).