Rhyparus cucullatus Skelley and Smith 2024, new species
Creators: name: Smith, Paul E. Skelley Andrew B. T.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Rhyparus
Rhyparus cucullatus

description: Rhyparus cucullatus Skelley and Smith, new species
Figures 1–5, 41
Diagnosis. A member of Rhyparus, distinguished from all other Western Hemisphere species by the generally smooth dorsal surface; discomedial costa of elytron swollen posteriorly, covering trichome and part of the large caudal bulb (Fig. 4–5), and with distribution in Guatemala (Baja Verapaz, Zacapa) (Fig. 41).
Description. Holotype female (Fig. 1–4). Body length 4.94 mm, width 1.75 mm. Elongate, almost parallel-sided, flattened, dark brownish black, surface generally dull, alutaceous, partly clothed with fine, pale yellow setae on head and at caudal bulbs of elytral costae.
Head. Surface dull, alutaceous, transversely subhexagonal. Clypeus trapezoidal in outline, anteriorly weakly concave in anterior view, concave between teeth in dorsal view; anterior margin weakly upturned with sharp tooth on each side of medial third, lateral thirds concave to rounded tooth anterior of clypeo-genal junction. Genae moderately lobed laterally, distinctly excavated anterior of eyes. Clypeocentral disc evenly convex, lacking costae; peridiscal impression strong basally, reduced and obsolete anteriorly. Frons with four small, distinct frontodiscal costae, equal in size and prominence. Head with widely scattered punctures, equal in size and distribution from base to apex; punctures with short, pale, yellow setae.
Pronotum. Surface dull, alutaceous, costae weakly glossy, widest in middle; with paramedian, discolateral, and submarginal costae equally distinct. Costae with row of minute punctures and setae on each side. Paramedian costae incomplete, most prominent at anterior margin, reduced and obsolete at weak constriction near anterior third; distinct and weakly diverging to posterior margin. Discomedian costa nearly straight, distinctly interrupted by fovea on anterior third, present at anterior margin. Submarginal costa complete, sinuate, with angulation just behind middle. All costal intervals impunctate, with exceptions as follows; interval between paramedian costal constriction with less than 12 indistinct punctures. Intervals between paramedian, discolateral, and submarginal costae anteriorly with four indistinct punctures. Basally, paramedian and discolateral costae each with two foveate punctures on each side, at base (heavily encrusted) and posterior quarter. Lateral margin strongly sinuate, reduced posteriorly; anterior lobes slightly more prominent than intermediate lobes that project triangularly.
Scutellum. Scutellar shield minute, narrow, apex acute.
Elytra. Surface with flattened intervals strongly alutaceous, costae weakly alutaceous; each elytron with five elevated costae separated by five flattened intervals. Costae moderately convex, low, not sharply convex; with row of minute setose punctures on each side. Juxtasutural costa complete from base to apex. Discomedian costa broader than others, straight from base to apex; gradually swelling at apex, extending over trichome and broadly touching caudal bulb. Discolateral costa slightly narrower than discomedian costa, nearly straight, curving into trichome apically. Posthumeral costa narrower that preceding, equally prominent, turning inward to trichome at apex. Submarginal costa slightly wider than posthumeral costa; with distinct angulate lobe at point where it turns inward to caudal bulb. Elytral humerus at base of posthumeral costa bearing fine punctures with short setae. Costal intervals of elytron flat; with two rows of strial punctures of moderate size, separated by more than two diameters within a row and between the rows; third interval with third intermediate row of punctures of nearly equal size, row ending in apical quarter; punctures in fourth interval larger, more distinct and somewhat transverse giving a slightly wrinkled appearance to surface. First and second elytral costal intervals with two rows of widely separated punctures, third costal interval with three puncture rows. Caudal trichomes small, narrowed. Caudal bulbs large; in dorsal view transverse, strongly angulate at end of submarginal costa, medially curving caudally near juxtasutural costa; dorsally rounded in posterior view; lacking distinct puncture, with fine scattered setae; surface of bulb and area between bulb and elytral margin equally alutaceous; posterior surface of bulb with large, coarse punctures.
Ventral thorax. Surface weakly dull, alutaceous. Metaventrite flattened, in the middle with distinct deep longitudinal median impression in posterior three-quarters, impression equally deep and wide along length; disc on either side with row of coarse punctures just outside of medial impression, rest of surface with coarse and irregularly spaced punctures, separated by one puncture diameter or more, decreasing in size anteriorly and laterally, all punctures bearing a short seta.
Abdomen. Abdominal ventrites 2–4 with narrow, transverse, anterior groove that is crenately margined, somewhat fluted interiorly; ventrites laterally with large, distinct, triangular depression, rest of surface with scattered, fine punctures bearing a short seta. Abdominal ventrite 5 (last) as long as preceding two ventrites medially; surface evenly coarsely punctate, punctures separated by one puncture diameter or less; with a small, transversely elongate, punctate fovea laterally; anterior margin with a narrow, crenated groove extending to lateral margin. Pygidium with central carina strong, split at basal third, Y-shaped, ending abruptly at apical third, not complete to apex; surface in lateral view angularly concave at base; each side with large, triangular, alutaceous areas occupying most of surface.
Legs. Profemur alutaceous, with large, impressed punctures; mesofemur and metafemur weakly glossy with fine punctures; all punctures bearing a very short seta. Mesofemur robust, with posterior margin bearing two weak angulations at middle and apical third. Metafemur narrow, weakly widened medially third. Protibia with bidentate apex; inner tooth greatly reduced; medial margin straight. Mesotibia with apex truncate; lacking medially projecting spine on inner apical angle; inner margin straight in apical third. Metatibia weakly widened to truncate apex; lacking medially projecting spine of inner apical angle small; inner margin straight in apical third. Mesotarsomere 1 as long as mesotarsomeres 2–4. Metatarsomere 1 as long as metatarsomeres 2–5 combined.
Male. Unknown.
Variation. The paratype female has a body length 4.38 mm, width 1.63 mm. Other than body measurements, there are no notable variations between the two specimens.
Material examined. Holotype female deposited in FSCA: “ GUATEMALA: Dept. Zacapa / Sierra de las Minas; Cerro los / Monos; nr. 15.11690, −89.68064; / 4 km nnw San Lorenzo; 2230 m / 18–21-V-2010; cloud forest / P. Skelley, at light // [red paper] HOLOTYPE ♀ / Rhyparus / cucullatus / des. 2024 / Skelley & Smith”.
Paratype. Only one additional female studied: “ GUATEMALA: Baja Verapaz / Los Ranchitos, Res. Quetzal / 31-V-2-VI-2015, 1680m / Coll. J.B. Heppner & E. Fuller” (1 CMNC).
Etymology. The species epithet refers to the enlarged caudal end of the discomedian elytral costa which covers the trichome. It is derived from the Latin “ cucullus ” meaning cap or hood, combined with “- atus ” meaning to have or provided with.
Comments. Rhyparus cucullatus presents a number of odd character states that make its placement into a species group difficult. However, the enlarged caudal bulb of the elytron is somewhat similar to the enlarged bulbs of R. isidroi Cartwright and Woodruff and R. vitikaboureki Mencl and Rakovič (see Mencl and Rakovič 2013). Both of these species have three rows of coarse punctures on the second elytral interval, while R. cucullatus has only two rows of moderate punctures. The elongate and swollen posterior end of the discomedian elytral costa that covers the trichome and touches the caudal bulb is unique for the genus in the Western Hemisphere.
description: Published as part of Smith, Paul E. Skelley Andrew B. T., 2024, Five unusual new species of Rhyparus Westwood, 1845 from Mexico and Central America (Coleoptera: Scarabaeidae: Aphodiinae: Rhyparini), pp. 1-19 in Insecta Mundi 2024 (91) on pages 2-4, DOI: 10.5281/zenodo.14662346