Ochthebius (s. str.) bajaensis, 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 : 41-43

Ochthebius (s. str.) bajaensis , new species

Figs. 4 (habitus comparison), 24 (habitus and aedeagus)

Type Material. Holotype (male): “ MEXICO: Baja California, Sur, 2.3 mi. W Mexico 1 on Bahia Tortugas road, III-19-1981, F. Andrews & D. Faulkner ” ( CDFA) Paratypes (105): Same data as holotype (4 CDFA) ; Mexico: Baja California, Norte , 1.9 mi. NE Catavina, collected among roots of grasses at margin of algae filled stream, 16.iii.1981, leg. F. Andrews & D. Faulkner (5 CDFA) ; Norte , 14.3 mi. SE Catavina, collected at margin of stock pond, 16.iii.1981, leg. F. Andrews & D. Faulkner (2 CDFA) ; Norte , 2.1 mi. NW Catavina, in small algae covered stream, 3.vii.1979, leg. A. R. Hardy & F. G. Andrews (9 CDFA) ; Norte , 2.1 mi. S Rosarito, Collected in marsh pools, 23.iii.1981, leg. F. Andrews & D. Faulkner (2 CDFA) ; Norte , 2.2 mi. S Rosarito, collected in marsh pools, 22.ix.1981, leg. F. Andrews & D. Faulkner (1 CDFA) ; Norte , 2.5 mi. NW Catavina, 13.vii.1979, leg. Giuliani, Hardy & Andrews (2 CDFA) ; Norte , 30.3 mi. E El Rosario, Collected in pools of intermittant stream, 24.iii.1981, leg. F. Andrews & D. Faulkner (24 CDFA) ; Norte, 57 mi. E El Rosario , 2 mi. E San Fernando Velicata, Collected at blacklight, 2.vii.1972, leg. F. G. Andrews & A. R. Hardy (3 CDFA) ; Norte, Isla Cedros north point, collected at night in pools of intermittant stream, 20–21.iii.1981, leg. F. Andrews & D. Faulkner (53 CDFA) . Some duplicates deposited in MCZ .

Differential Diagnosis. This member of the O. interruptus Group will key Ochthebius (s.str.) couplet 17 in Perkins (1980: 301), but diverges here in that the metaventrite in males has a large glabrous area, whereas in females the metaventrite is completely hydrofuge pubescent. The aedeagus is somewhat similar to that of O. aztecus Sharp , but differs in shape of both the main-piece and the distal piece. There are differences in the dorsal habitus of the two species, and the 6 th abdominal ventrite, which is totally hydrofuge pubescent in O. aztecus , and only sparsely pubescent (non-hydrofuge) in O. bajaensis n. sp. Reliable determinations will require dissection and careful examination of the male genitalia ( Fig. 24 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.95/0.85; head width 0.50; pronotum 0.42/0.68 (width including hyaline margin), PA 0.57, PB 0.45 (PB sclerotized part); elytra 1.23/0.85. Habitus as illustrated ( Fig. 24 ). Dorsum black, legs and maxillary palpi brown. Interocular foveae large and deep, each equal to distance separating them. Ocelli distinct, shining. Frons finely, moderately densely punctulate, punctures ca. 1xef, interstices 1–2xpd on disc, contiguous or nearly so near eyes, interstices shining on disc, microreticulate laterally. Clypeus more finely and more densely punctulate, interstices very weakly shining. Labrum with apicomedian indentation.

Pronotum widest near anterior 1/4, sides sinuately attenuate to base. Anterior margin without postocular emarginations; hyaline border well developed. Lateral hyaline border wide, side weakly arcuate, narrowing anteriorly, ended at about anterior 1/4, posteriorly continuing narrowly but distinctly around posterior angles and along base. Disc with microreticulate, moderately wide, moderately deep midlongitudinal sulcus, ended well before anterior and posterior hyaline borders, anterior and posterior admedian foveae moderately deep, microreticulate, coarsely punctate, some punctures confluent, posterior foveae very large, much larger than anterior; relief shining, finely sparsely punctate, more coarsely punctate laterally. Lateral depression, lateral fossulae and area between fossula and posterior foveae more densely coarsely punctate than central area of discal relief. Posterior angles with broad, very shallow depression.

Elytra: Elongate oval, broadest about middle. Summit of posterior decliving at ca. midlength. Explanate margins narrow. Apices in male narrowly separately rounded, in female conjointly rather sharply rounded. Ten distinct series of punctures, series not striate-impressed except sutural in distal 1/4, punctures and interstices about 2–3xef on disc, becoming finer and more separated laterally and apically, each puncture with fine recumbent distinctive seta. Intervals rounded, weakly shining, effacedly microreticulate, ca. 1xpd.

Venter. Mentum finely sparsely setiferously punctate, interstices shining. Metaventrite in male pubescent laterally, disc with large glabrous area, microreticulate, dull; female metaventrite completely hydrofuge pubescent. Abdominal ventrites 1–5 entirely clothed with dense hydrofuge pubescence; 6 effacedly mcr., weakly shining, sparsely pubescent in distal 1/2. Basal protarsomeres in male with suction setae; suction setae absent in female.

Distribution. Currently known only from Baja California, Mexico.

Etymology. Named in reference to the known geographical distribution.

Figures

FIGURE 4. Dorsal habitus of species of Ochthebius.

FIGURE 24. Ochthebius (s. str.) bajaensis, new species, holotype habitus and aedeagus.