Anillinus simplex Harden & Caterino, 2024, sp. nov.

Anillinus simplex sp. nov. Figs 21 E, 24 E, 29, 30 G – I, 33 A – C Type material. Holotype male: (USNM), point mounted, with abdominal ventrites glued to point and genitalia in Euparal on microslide pinned beneath specimen. Original label: “ USA: SC, York Co. Kings Mountain S. P. 35.1307, - 81.3649. 26. September. 2020. C. W. Harden. Under rock near stream. ” “ [QR Code] CLEMSON-ENT CUAC 000185896 ” “ Harden DNA Voucher CWH- 247 Anill. ‘ kingsmtnsp 1 ’ M Ext. 30 / September / 2020 [green-bordered label]. ” “ HOLOTYPE Anillinus simplex Harden & Caterino [orange cardstock] ” GenBank: OR 853342, OR 839331, OR 839570, OR 837888, OR 838032, OR 838222. Paratypes (n = 46, ADGc, CMNH, CNC, CUAC, FSCA, LSAM, NCSU, NHMUK, OSAC, USNM, VMNH). USA • South Carolina • York Co. • Kings Mountain State Park; • 1 ♂; same data as holotype; CUAC 000170024, CWH- 248; CUAC; • 1 ♀; same data as holotype; CUAC 000170025, CWH- 249; CUAC; • 8 ♂, 2 ♀; same data as holotype; CUAC 000170026 to CUAC 000170035; CNC, CUAC; • 3 ♂; same data as holotype; ADGc; • 12 ♂, 12 ♀; 35.13198, - 81.36608; 26 Sep. 2020; C. W. Harden leg.; Berlese, deep litter and topsoil, oak, maple, sourwood, pine; CUAC 000170036 to CUAC 000170059; CMNH, CNC, FSCA, LSAM, OSAC, USNM, VMNH; • 1 ♀; 35.13062, - 81.36439; 26 Sep. 2020; C. W. Harden leg.; Berlese, litter near stream, mesic hardwoods; CUAC 00017060; VMNH; • 2 ♂, 1 ♀; 35.13018, - 81.36205; 23 Dec. 2021; C. W. Harden leg.; under embedded rock; CUAC 000167147 to CUAC 000167149; NCSU; • 1 ♂, 2 ♀; 35.1301, - 81.3637; 23 Dec. 2021; C. W. Harden leg.; Berlese, soil near seepage; CUAC 000170061 to CUAC 000170063; NHMUK. GenBank accession numbers for paratypes: OR 839571, OR 853339, OR 839328, OR 839572, OR 837889, OR 838033, OR 838223. Other material (n = 30, CUAC, CWHc, NCSU). USA • North Carolina • 3 ♂, 5 ♀; Gaston Co.; Crowders Mountain State Park, near Linwood parking; 35.2417, - 81.2717; 29 Apr. 2023; C. W. Harden leg.; Berlese, sifted duff / litter; NCSU ; • 2 ♂; same data as previous; under embedded rock; CUAC 000182312 and CUAC 000182313, CWH- 510 and CWH- 511; CUAC; • 1 ♂; Gaston Co.; Crowders Mountain State Park; Ridgeline Trail at Road 1104; 35.1977, - 81.3152; 29 Apr. 2023; C. W. Harden leg.; under embedded rock; CUAC 000182314, CWH- 512; CUAC; • 3 ♂; Gaston Co.; Crowders Mountain State Park; Ridgeline Trail at Road 1104; 35.1977, - 81.3152; 29 Apr. 2023; C. W. Harden leg.; under embedded rock; CWHc; • 1 ♀; Gaston Co.; Crowders Mountain State Park, near Pinnacle, open piney ridge; 35.2011, - 81.3148; 29 Apr. 2023; C. W. Harden leg.; under rock; CWHc; • 1 ♂; Gaston Co.; Crowders Mountain State Park, near Pinnacle, recently washed gully; 35.1993, - 81.3152; 29 Apr. 2023; C. W. Harden leg.; under rock; CWHc; • 3 ♂; Gaston Co.; Crowders Mountain State Park, near Pinnacle, recently washed gully; 35.2031, - 81.3144; 29 Apr. 2023; C. W. Harden leg.; under rock; CWHc; • South Carolina • York Co. • 7 ♂, 3 ♀; Kings Mountain State Park; 35.13198, - 81.36608; 26 Sep. 2020; C. W. Harden leg.; Berlese, deep litter and topsoil, oak, maple, sourwood, pine; CWHc; • 1 ♀; Bethany; 35.116, - 81.305; 9 Feb. 1998; J. C. Ciegler leg.; in leaf litter; CUAC. Diagnosis. Males of A. simplex are the only members of the valentinei group known to lack ventral adhesive setae on protarsomere 2, but this character is difficult to confirm without strong magnification. From most anillines occurring in South Carolina, members of A. simplex can be recognized by their small size (ABL <1.65 mm) and effaced microsculpture on the sides of the vertex. The median lobe of A. simplex is distinctive, with a short, thick well-sclerotized curved flagellum in the internal sac and the absence of other well-sclerotized structures (Fig. 30 I). Some individuals of A. murrayae from southern Pickens Co. overlap in size with members of A. simplex but are easily distinguished by the different male and female genitalia (Figs 21 D, 30 J – N). Description. Habitus Body small (ABL = 1.45–1.64 mm), moderately convex, slightly ovoid, robust (EW / ABL = 0.35–0.38) (Fig. 33 A). Integument Dorsal microsculpture of forebody variable. In specimens from the type locality, microsculpture is effaced from most of the pronotum, present only along extreme outer margins, and weakly impressed there, and absent from large portions on both sides of the vertex posteriorly. In specimens from Crowders Mountain, the pronotum is entirely covered in strong, easily visible isodiametric microsculpture, and the smooth patches on the vertex are smaller. Head HW / PW = 0.71–0.77. Three pairs of supraorbital setae present, outer posterior pair shorter than other two. Frontoclypeal horn well-developed (Fig. 33 C). Pronotum Relatively short (PL / ABL = 0.22–0.24) and broad (PW / EW = 0.80–0.85), sides evenly convergent or slightly sinuate before slightly narrowed posterior angles (PbW / PW = 0.73–0.78). Elytra Slightly ovoid, widest approximately middle, length variable (EL / ABL = 0.51–0.57). Umbilicate punctures relatively large and conspicuous. Striae weakly impressed, difficult to trace. Legs Profemora of males unmodified; protarsomere 1 of males expanded and with inner margin spinose, protarsomere 2 unmodified and apparently lacking ventral adhesive setae in most specimens (a single adhesive seta observed in one male). Mesofemora of males unmodified. Metafemora of males with patch of coarse papillate microsculpture medially on posterior face. Abdominal ventrites Unmodified in either sex (Fig. 33 B). Male genitalia Ring sclerite (Fig. 24 E) moderately small (RL / ABL = 0.28) and asymmetrical, strongly narrowed anteriorly. Median lobe (Fig. 30 I) evenly curved, slightly twisted dorsally from level of basal lobes, gradually expanded in width from base to apex. Ventral margin slightly expanded, asetose. Apex small and evenly rounded. Left side of base with semicircular excavation visible in left posterolateral aspect, with carina extending distally from the excavation to approximately middle. Internal sac with well-sclerotized flagellum short and stout, evenly curved, with one short basal extension. Ventral surface of internal sac with field of weakly sclerotized teeth. Sides of internal sac near ostium appearing grooved with curved parallel lines. Ostial plate on left side, small and weakly sclerotized. Right paramere narrow, with four long apical setae (Fig. 30 H). Left paramere conchoidal, with four ventral subapical pores, the apical two bearing short setae (Fig. 30 G). Female genitalia Spermatheca long, gradually and slightly enlarged distally, stem slightly sinuate before basal curve, which is rotated perpendicular from rest of stem (Fig. 21 E). Spermathecal duct short and not coiled. Distribution. Known only from Kings Mountain, a short linear monadnock spanning from York County, South Carolina to Gaston County, North Carolina (Fig. 29). Sympatry. This species has been collected with A. montrex and A. cornelli underneath embedded rocks. Serranillus monadnock sp. nov. also occurs at Kings Mountain State Park. Natural history. Specimens have been collected in February, April, September, and December, from underneath embedded rocks on sandy clay rich soil near an ephemeral stream and through Berlese extraction of sifted litter and soil. Species status justification. The male and female genitalic characters are unique within the genus, and the DNA sequence data indicate A. simplex is most closely related to A. cornelli, A. castaneus, and “ South Carolina, Chestnut Ridge ”, all of which differ markedly in male genitalic characters, especially by possessing several sclerotized spines in the internal sac. Derivation of species name. A noun in apposition, from the Latin, meaning “ simple ”, in reference to the structure of the median lobe of the aedeagus, which lacks the complex sclerotized structures in the internal sac that are present in the other South Carolina species in the valentinei group, and the lack of modifications to male protarsomere 2. ‘ elongatus group’ The five described species of the elongatus group were revised by Harden and Caterino (2024) and are discussed and illustrated in more detail in that paper.