Xestochironomus digitulus Fusari & Baranov 2026, sp. nov.

Xestochironomus digitulus Fusari & Baranov sp. nov. Type material. Holotype: • 1 male, slide mounted. DOMINICAN REPUBLIC, Blanco, 18°52'42.7"N, 70°30'25.7"W, 30. xi. 2019, light trap, A. Höcherl, leg. (EBD I-016278). Paratypes: • 1 male, slide mounted, same data as holotype (EBD I-016279). • 1 male, slide mounted, same data as holotype (LEA). • 1 male, slide mounted, Blanco, 18°52'59.9"N, 70°30'28.8"W, 01. xii. 2019, CDC light trap, A. Höcherl, leg. (LEA). • 2 males, slide mounted, Blanco, 18°52'59.9"N, 70°30'28.8"W, 01. xii. 2019, CDC light trap, A. Höcherl, leg. (MNHN-EJM). • 1 male, voucher, slide mounted, same data as holotype (MNHN-EJM), GenBank sequences: PV 761055 – PV 761056. • 1 female, voucher, slide mounted, same data as holotype (EBD I-016280), GenBank sequences PV 761059 to PV 761060. Etymology. The species name refers to the pinkie-shaped lobe of the gonostylus (from the Latin, digit - (finger) and - ulus (small, little). Diagnosis. The new species can be distinguished from congeners in having the abdominal tergites III – IV with dark, transverse bands; a long, slender anal point; and the apex of the gonostylus slightly forked, with shallow concavity between the forks and one pinkie-finger-like lobe. Description. Male (n = 7, except when stated otherwise). Total length 2.95–3.26, 3.13 mm (5). Wing length 1.50–1.80, 1.69 mm (6). Total length / wing length 1.71–1.98 (5). Wing length / profemur length 1.77–1.90 (3). Coloration: head and palp pale brown (Fig. 1 A). Antenna pale brown. Thorax brownish (Fig. 1 B). Halters brown. Wings with faint brownish areas on brachiolum, arculus, and crossvein RM; membrane transparent, slightly brownish along wing margin, from apex of R 4 + 5 to apex of M 1 + 2, and on humerus between Cu and An (Fig. 1 C). Abdominal segments coloration as follows (Fig. 1 D): TI yellowish with dark-brown lateral bands; TII yellowish with dark-brown lateral and posterior bands; TIII – IV yellowish with dark-brown posterior bands; TV – VI yellowish with dark-brown lateral and posterior bands; TVII brown in anterior 2 / 3 with dark-brown, rectangular anteriomedial spot and posterior 1 / 3 of segment yellowish; TVIII yellowish. Legs (Fig. 1 E). Foreleg: femur yellowish with proximal and apical ¼ brown, tibia yellowish with 1 / 3 brown proximally, tarsomere 1 yellowish with brown ring proximally, tarsomere 2–4 brownish with proximal and apical ring pale, tarsomere 5 brownish with proximal ring pale. Mid- and hind legs: femur brownish, tibia yellowish with proximally ring brown and proximal 1 / 5 pale brown, all tarsi yellowish. Head. AR 1.2–2.0 (4). Temporal setae 9–10 (2). Clypeus with 10–18 (3) setae. Tentorium 119–139 (2) μm long. Palpomere lengths (1–5 in μm; n = 4): 23–36; 48–56; 124–145; 119–155; 201–242. Thorax (n = 5). Acrostichals 12–16, 15. Dorsocentrals 15–25, 21, partly biserial. Prealars 4–6, 5. Scutellum with 8–13, 11 setae. Wing. VR = 1.16–1.23 (5). Brachiolum with 2 (3) setae. R with 27–34 setae; R 1 with 27–36 setae; R 4 + 5 with 42–49 setae; RM with 6 setae; M with 2–3 setae apically. Squama with 7 (2) setae. Legs. Combs of midtibia 17–19 (3) μm and 26–31 (3) μm long spurs. Combs of hind tibia 21–24 (3) μm and 27–31 (3) μm long spurs. Width at apex of foretibia 46–50 (3) μm, of midtibia 41–51 (3) μm, of hind tibia 41–54 (3) μm. Lengths (in μm) and proportions of legs in Table 1. Hypopygium (Figs 1 F, 2 A, B). Tergite IX with 14–16 strong median setae and 6–8 weaker setae along the posterior margin on each side of the anal point, and several fine setae on the ventral side. Anal tergite bands V-shaped, separated. Laterosternite with 2–4 setae. Anal point slender, 48–59 (4) μm long, 61–65 (2) μm long in lateral position (from the base). Phallapodeme 63–73 (3) μm long. Transverse sternapodeme curved, 24–30 (3) μm long. Gonocoxite 110–135, 118 (5) μm long. Superior volsella hooked, 54–85, 79 (6) μm long, with 1 strong lateral seta and 1 / 3 basal setae. Inferior volsella 64–101, 91 (5) μm long, with 7–10 dorsal setae, 75–81 (3) μm long apical seta. Gonostylus bifid, 135–149, 143 (5) μm long, one pinkie-like lobes with 10–20 (4) μm long apical seta. HR 0.74–0.92 (5). HV 1.98–2.31 (5). Description of female (n = 1). Total length 2.78 mm. Wing is bent, no observations possible. Coloration similar to male. Head. Lengths of flagellomeres (μm): 80, 105, 104, 86, 104. Temporals setae 14. Clypeus with 15 setae. Lengths of palpomeres (μm). 34, 48, 136, 142, 249. Thorax. Acrostichals 12; dorsocentrals 29, partly biserial; prealar 6; scutellars 11. Legs. Combs of midtibia 20 μm and 36 μm long spurs. Combs of hind tibia 19 μm and 42 μm long spurs. Width at apex of foretibia 56 μm, of midtibia 50 μm, of hind tibia 57 μm. Lengths (in μm) and proportions of legs in Table 2. Genitalia (Fig. 3). Tergite IX with 25 setae. Gonocoxite IX with 6 setae. Gonapophysis IX notum 236 μm long. Seminal capsules spherical, 49 μm wide. Gonocoxapodeme 225 μm long. Coxosternapodeme 134 μm long. Cercus 88 μm wide. Immatures. Unknown. Distribution. Known only from the Dominican Republic.