Spelaeodelphax nexus Santos & Asche & Hoch & Ferreira 2026, sp. nov.

Spelaeodelphax nexus Santos & Asche sp. nov. Figs 2 E, F, 3 A – C, 4 A – C, 5 A – G, 6 A – D, 7 A – D, 8 A – P, 9 A – F, 10 A – F, 11 A – D, 12 A – D Type material. Holotype. • Male, Brazil, Bahia state, Carinhanha municipality, Lapa dos peixes I cave (UTM 13°48'55.6"S, 43°57'17.2"W, 23 K), 07. ix. 2023 (ISLA 126058) (Fig. 1). Holotype condition: Holotype condition: Not dissected, stored in individual vials in 70 % ethanol. Paratypes. • Same data as holotype except for 1 ♂ dissected, stored in individual vials in 70 % ethanol (ISLA 126059) (only male genitalia), 1 ♀ (ISLA 126061) 4 nymph (ISLA 126062), and 04. vi. 2024, 1 ♂ (ISLA 126062), 1 ♂ (ISLA 126063), 1 ♂ (ISLA 126065), 1 ♂ (ISLA 126066), 1 ♂ (ISLA 126067) (dissected), 1 ♂ (ISLA 126068), 1 ♂ (ISLA 126069), 1 ♀ (ISLA 125912), 1 ♂ (ISLA 125911) (SEM). Description. Adults. Figs 2 E, F, 3 A – C, 4 A – C, 5 A – G, 6 A – D, 7 A – D, 8 A – P. Diagnosis. Habitus. Small, light-colored and strongly troglomorphic delphacid devoid of compound eyes and ocelli, tegmina strongly reduced in length without recognizable venation, hind wings reduced to narrow pads. Configuration of male and female genitalia as described for the genus. For details of male genitalia see below. Coloration (preserved specimen). As in Figs 3, 4, predominantly deep yellow (85) on head, thorax, abdomen and genitalia, some areas in pale yellow (89) principally legs, head laterally (gena) and spaces between segments, especially of the abdomen. Body length. Male. 1.6–1.8 mm (n = 7) (Fig. 3); Female. 1.9–2.0 mm (n = 2) (Fig. 4). Configuration, shape and proportions of head, thorax and female terminalia as proposed for the genus. Some figures and measurements are provided here. Head. Vertex (Figs 3 A, 5 A, 6 A): width (0.20) length (0.04). Frons (Figs 3 B, 5 B, 6 B, C): width (0.39) length (0.38). Antennae (Fig. 5 E): Pedicel width (0.09) length (0.13). Thorax. Pronotum (Figs 3 A, C, 5 A, C). Mesonotum (Figs 3 A, C, 5 A, C): width (0.54) length (0.30). Tegmina (forewings) (Fig. 5 F, G): length (0.57). Hind legs (Figs 3 B, C, 5 D): length (0.91). Male genitalia. Pygofer (Fig. 8 A – D, G, H) bilaterally symmetrical; with caudal margin irregularly convex without lateral processes; in lateral view with irregular caudal margin, without lateral processes; dorsal margin slightly convex / irregular; in ventral view, margins in W-shaped with small triangular ventromedial process; in caudal view rounded, armature of diaphragm weakly sclerotized wider than tall; opening to inner chamber rounded, opening for gonostyli ovoid small approx. 3.0 times smaller than opening to inner chamber. Anal segment (Fig. 8 A – D, I – J) with paired lobes slightly asymmetrical, left lobe slightly larger than right one; in caudal view margin between lobes deeply concave; epiproct and paraproct rather small. Gonostyles (Fig. 1 A – C, E, F) short and slender, in lateral view pointing dorsocaudad with tip slightly surpassing laterocaudal margin of pygofer, widest in basal two thirds, with median margins opposed and close to each other, ventral and dorsal margins slightly sinuate; in distal third narrowing, forming a pair of pincers with keyhole-shaped opening between styles. Aedeagus (Fig. 8 K – N) tubular, asymmetrical; shaft with four spines: a rigid spine arising right laterally near base (long, tubular, compressed ventrally, curved and directed towards apex of shaft), 2 rigid spines at about midlength on left and right side (both compressed, triangular, one short, the other slightly longer), and a movable sinuate spine arising ventrally near apex (in repose directed basally). Flagellum moderately long, slightly surpassing midlength of aedeagal shaft, laterally with serrated margin. Female genitalia. As described for the genus. Immatures. Figs 9 A – F, 10 A – F, 11 A – D, 12 A – D. Nymph 5 th instar. Body length. 1.9 mm (n = 3). Habitus. Slightly dorsoventrally flattened, about twice as long as maximally wide, widest at level of forewing pads and 5 th abdominal segment. Colouration. All parts whitish to very pale yellow. Head. Head without compound eyes, ocelli or traces of them; width at posterior margin of vertex distinctly narrower than pronotum at posterior margin (about 0.4: 1). Vertex short and broad, almost pentagonal, apex anteriorly slightly produced and medially notched, at posterior margin about twice as wide as medially long, lateral and anterior margins ridged, medially a very faint longitudinal carina separating vertex in 2 halves; transition to frons broadly rounded. Frons rather wide, about 1.3 times wider than medially high, maximal width at level of antennae; lateral margins strongly convex, paired intermediate carinae very shallowly convex, well separated from each other, converging towards apex; surface of lateral areas shallowly vaulted, of median area deeply concave; frontoclypeal margin slightly arched and notched. Head with a total of 30 sensory pits, i. e., 12 pits in lateral areas of frons and 3 pits in “ preocular ” area, frontal pits arranged in rows of 6 along intermediate and lateral carinae; variation: in one individual only 5 lateral pits on right side. Sensory pits on head as well as on the other tagmata oval to subcircular, from a cup-like socket at the outer margin arising a seta which is exposed horizontally over the pit without attaining lateral or opposite margins; seta distally knob-like dilated. Post- and anteclypeus shallowly vaulted, smooth, devoid of carinae, post- and anteclypeus separated by a transverse notch. Rostrum distinctly surpassing post-trochanters; tip of rostrum as in adults. Antennae short, scape ring-like; pedicel about 4 times longer than scape, subglobose, distally with about 10 sensory-plaques consisting of a crown of 3–4 longer finger-shaped processes arising from a common socle and 4–5 short rigid spines at base. 3 rd antennal joint (“ flagellum ”) distinct, knob-like, about 0.25 times shorter than pedicel, surface with 2–3 transverse wrinkles, distally continuing in a long arista (“ first projection ” sensu Shi and Yang 1996) and a short peg-like process or arista (“ second projection ” sensu Shi and Yang 1996), both with surface wrinkled; dorsally at distal margin of the 3 rd antennal joint above the bases of the aristae a distinct Bourgoin´s organ consisting of about 20 slender finger-shaped processes forming a distally converging crown. Genae devoid of oblique carina, antennal bases large, subcircular, lamina mandibularis not defined by sutures, distally filiformous. Thorax. Pronotum broad and short, about 5.4 times wider than long in middle line, medially slightly shorter than vertex (0.8–0.9: 1); posterior margin straight transverse; medially a membraneous cleft, no ridged carina; dorsolateral carinae oblique, ridged, reaching from anteromedian corner of disc towards lateral posterior margin, dorsal area of disc along carina with 4 sensory pits; lateral lobes at posterior and ventral margin with a total of 4 sensory pits; surface of disc very shallowly concave, nearly plane, surface of lateral lobes slightly convex. Meso- and metanotum medially divided by a longitudinal membraneous furrow, no median carina. Mesonotum approximately 3.8–4 times wider than medially long, medially about twice as long as pronotum; posterior margin shallowly concave, at lateral discal carina almost rectangularly bent inwards; disc narrow, lateral discal carina diverging laterocaudad, attaining posterior margin; mesonotum with a total of 16 sensory pits; mediad along discal carina 2 sensory pits, laterad of carina close to posterior margin another sensory pit; forewing pads large, slightly surpassing midlength of hindwing pads; pads sublaterally at posterior margin with a short ridge and a long subcostal carina; forewing pads with a single pit laterad of sublateral ridge, 2 pits at distal margin and 2 pits between subcostal and costal margin. Metanotum about 3.5 times wider than medially long, medially about as long as mesonotum, posterior margin oblique with pads rounded, attaining anterior margin of first abdominal tergite; disc plane, narrow, lateral discal carina straight, slightly diverging caudad, laterad along carina 2 sensory pits. Legs moderately long, slender, normally shaped, without significant dilation or flattening of particular limbs. Pro- and meso-femora at outer distal margin with a short tooth-like protuberance; pro- and mesotarsomeres 2 - jointed with 1 st tarsomere rather short, scale-like; post-tarsomeres 3 - jointed. Post-trochanters medially with a narrow row of 10 parallel ribs forming a cog-wheel structure. Post-femora anteriorly at outer side with a small knob-like protuberance. Post-tibiae about twice as long as post-tarsomeres combined, laterally with 2 small spines, one near base, the other distinctly basad of midlength; distally with 5 coarse spines and a short post-tibial spur. Postbasitarsi only little longer than 2 nd and 3 rd post-tarsomeres together, about 3 times longer than post-tibial spur; postbasitarsi distally with 4, 2 nd post-tarsomeres with 3 stout spines in a transverse row, 2 nd post-tarsomeres relatively short. Pretarsi with aroliae very large, pillow-like with several longitudinal ribs, lateral claws short. Post-tibial spur subconical, terete, with a few irregularly ordered bristles. Abdomen. Tergites mediodorsally incised, distal tergites with sharply ridged crest, no wax-plates on tergites; tergites I – III devoid of sensory pits; tergite IV with a single sublateral pit, extralateral area devoid of pit; tergite V with a sublateral and a lateral pit, tergites VI – VIII with a subdorsal, a sublateral and a lateral pit, extralateral areas V – VIII anteriorly with a single pit; an intermediate or sublateral carina of tergites missing, only on tergite VIII a short sublateral ridge; 9 th abdominal segment with a single dorsal and 2 ventrocaudal sensory pits; in the late 5 th instar males the outline of the pygofer and lateral anal combs, and i