Ochthebius (s. str.) explicitus, Perkins, 2023

Perkins, Philip D., 2023, New Neotropical and Nearctic species of water beetles in the genera Hydraena Kugelann and Ochthebius Leach, a key to North American genera and subgenera of the family, new distribution records, and a synopsis of ecology, behavior and morphology related to aquatic life (Coleoptera: Hydraenidae), Zootaxa 5367 (1), pp. 1-86 : 43-45

Ochthebius (s. str.) explicitus , new species

Figs. 4 (habitus comparison), 25 (habitus and aedeagus)

Type Material. Holotype (male): “ MEXICO: Veracruz, Coatepec, Río Huehueyapan, Agua Alegre , 12.iii.2002, 19°26’55’’ N, 96°58’ 54’’W, 1195 m, R.Arce col.” ( IEXA) . Paratypes (13): Same data as holotype, except 28.iv.2004 (10 IEXA) ; Veracruz, Apazapan, Balneario Carrizal, Rio La Antigua , 19°19’14’’N, 96°37’42’’W, 206 m, R. Arce col. (2 IEXA) . Veracruz, Xico, Xico Viejo, 16.viii.1998, Bosque mesofilo de Montaña, 19°26’42’’N, 97°03’21’’W, 1750 m R. Arce col. (1 IEXA) .

Differential Diagnosis. Readily differentiated from other species by the unusual elytral sculpture: 10 distinct series of exceeding fine, less than 1xef, closely spaced punctures, each puncture with white seta that overlaps following puncture, together each series forming unilinear white line, which are separated by the very wide, flat intervals. The combination of elytral sculpture and pronotal sculpture, with lyre-shaped discal area, clearly separate members of this species from others which also have the anterior margin of the pronotum with postocular emarginations, presented in the key to Ochthebius (s.str.) Perkins 1980: 299).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 2.02/0.95; head width 0.55; pronotum 0.48/0.71 (width including hyaline border), PA 0.59, PB 0.48 (sclerotized part only); elytra 1.25/0.95. Habitus as illustrated ( Fig. 25 ). Dorsum black, legs and maxillary palpi dark brown. Head dorsally and pronotum with distinctive moderately long white seta from each puncture. Interocular foveae only moderately deep, width of each slightly less than distance separating them. Ocelli small, shining. Frons moderately coarsely, moderately densely punctulate, punctures ca. 1–2xef, interstices 1–2xpd on disc, contiguous or nearly so near eyes, interstices shining on disc, microreticulate laterally. Clypeus punctation similar to frons, interstices very weakly shining. Labrum of male with apicomedian indentation.

Pronotum widest near anterior 1/4, sides sinuately attenuate to base. Anterior margin with shallow postocular emarginations, demarcated medially by small point; hyaline border well developed. Lateral hyaline border wide, side weakly arcuate, narrowing anteriorly, ended at about anterior 1/5, posteriorly continuing narrowly but distinctly around posterior angles and along base. Disc with hint of midlongitudinal sulcus indicated by row of punctures (see Remarks); anterior and posterior admedian foveae shallow, lateral margins abrupt and confluent, forming sinuate lines, and together delimiting lyre-shaped disc. Punctures of median area of disc moderately coarse, ca. 2–3xef, interstices ca 1–2xpd, shining. Punctures in posteromedial foveae smaller, confluent. Lateral depressions very densely punctate, rugulose. Posterior angles with broad, shallow rugulose depression.

Elytra: Elongate oval, broadest about middle. Summit of posterior declivity at ca. midlength. Explanate margins narrow. Apices in both sexes separately rounded, more distinctly so in male. Elytra shining, with ten distinct series of exceeding fine, less than 1xef, widely separated punctures, each puncture with white seta that overlaps following puncture, together forming unilinear white lines; series not striate-impressed except sutural in distal ¼, interstices. Intervals very wide, ca. 4–6xpd.

Venter. Mentum finely sparsely setiferously punctate, interstices shining. Prosternum with midlongitudinal carina. Metaventrite in both sexes hydrofuge pubescent. Abdominal ventrites 1–5 entirely clothed with dense hydrofuge pubescence; 6 effacedly mcr., weakly shining, sparsely pubescent in distal 1/2. Last abdominal tergite of male with shallow apicomedian emargination, female rounded. Basal protarsomeres in male with suction setae; suction setae absent in female.

Remarks. There is variation is the degree of development of the midlongitudinal sulcus of the pronotum: in one male it is totally absent; in the holotype it is faintly indicated by a row of punctures; in most males it is very shallow and very narrow, located only on the anterior part of the disc; in females it is deeper and wider, and again located only on the anterior part of the disc.

Distribution. Currently known only from a few localities in Veracruz State.

Etymology. Named in reference to the elytral sculpture, which has very discrete, very fine closely spaced serial punctures that are separated by very wide, flat and smooth intervals.

New species from Panama

Figures

FIGURE 4. Dorsal habitus of species of Ochthebius.

FIGURE 25. Ochthebius (s. str.) explicitus, new species, holotype habitus and aedeagus.