Epuraea (Orthopeplus) plenasulca Cline

Cline, Andrew R. & Carlton, Christopher E., 2004, Two New Species of Epuraea (Orthopeplus) (Coleoptera: Nitidulidae) from Mexico, The Coleopterists Bulletin 58 (2), pp. 261-270 : 268-269

Epuraea (Orthopeplus) plenasulca Cline , new species

( Figs. 3 , 6, 9, 12, 15, 18, 21)

Type Series. HOLOTYPE ($). 60 km S. Mexico D. F., Mex. 7,600 9, pines, 24 June 1948, F. Werner and W. Nutting . PARATYPES (2 $$). MEXICO, Michoacan District, Rosencheve, Rt. 15, km 129, 7–8 July 1965, Flint and Ortiz collr. All types deposited in USNM .

Description. Body uniformly dark reddish black, legs lighter, nearly testaceous. Minute fine grey pubescence covering dorsum. Length: mean¼2.2 mm, Width: mean¼1.0 mm, Depth:mean¼ 0.8 mm. Head broad with a large U-shaped furrow extending from one side of the head to the other. The furrow originates just behind each orbit, and terminates medially near the clypeus ( Fig. 3 ). Head surface densely punctate, punctures,1 eye facet wide, interspaces finely rugulose on vertex becoming smooth and shiny at occiput. Labial palpus large and swollen apically. Labial palpus with terminal segment broad and somewhat square-shaped, and with large pit at apex that extends across entire width of the segment (Fig. 6). Maxillary palpi with terminal segment much longer than basal two segments combined. Basal segments distinctly dorso-ventrally flattened into disc-shaped segments (Fig. 9). Antennal club compact. Terminal segment broadly rounded at the apex, subequal to preceding segment, and smaller than the basal segment. Small erect setae originating laterally from antennomeres 9–11. Antennal segments 3–5 all triangular in shape, segment 3 equal in length to segment 2. Antennal grooves short and convergent. Pronotum moderately concave along anterior one-third, with two pronounced humps on each side of the concavity. Concavity not more than one-tenth the length of the pronotum. Sides moderately explanate anteriorly becoming obsolete posteriorly (Fig. 15). Surface densely finely punctate, punctures 1.5 width of head punctures, interspaces smooth and shining, punctures separated by 1– 1.5 puncture width. Scutellum somewhat hemispherical with distinct lateral angles, but apex rounded. Elytra surface finely densely punctate, similar to pronotum, but less shining. Apices separately rounded exposing most of the pygidium. Lateral margins narrowly explanate. Epipleura narrow, extending the entire length of the elytra. Pygidium broadly triangular with apex only slightly rounded, nearly truncate. Apical margin with sparse scattered pubescence. Surface densely finely punctate, particularly in the middle of the structure, and less so along the lateral margin. Anterior margin with two distinct indentations near lateral angles (Fig. 18). Prosternal process in ventral aspect elongate and narrow, extending past procoxae. In lateral aspect somewhat convex over procoxae, but with pronounced declivity posteriad to the coxae (Fig. 12). Mesocoxae narrowly separated. Abdominal sternite 1 subequal in length to sternites 2–4 combined. Abdominal process forming acute tip between metacoxae. Ventral view of the anterior margin of the pronotum exhibiting small lobes near the lateral angles. Protibia expanded in apical third. Lateral margin with fine crenulations. Apical spine small, as long as first tarsomere. Broad flat teeth on apical posterior margin. Setae in serial row along medial ridge. Few scattered setae throughout the tibia. Mesotibia with medial margin broadly concave. Setae originating from the medial margin present along most of the entire length. Few setae present on the lateral margin. Two fossae present, one on the apical third of the tibia and one on the medial half. The median fossa being deeper than the apical fossa. Paired apical spines small and symmetrical in length. Several broad flat teeth on apical margin. Metatibia very slender in proximal third. Lateral border moderately convex. Both medial and lateral border bearing short stiff setae. Apical border bearing flat teeth. Apical spines short and slender, not longer than tarsomeres 1–2 combined.

Male genitalia not known. Ovipositor small and compact, paraprocts greatly reduced. Gonocoxites heavily sclerotized, fused medially, distinctly separated basally and apically (Fig. 21). Basal indentation with heavily sclerotized median furrows present on each gonocoxite. Apical border of gonocoxite broadly rounded with one large socket. Each socket bearing a short gonostylus. Gonostyli oriented obliquely.

Etymology. Specific epithet derived from the condition of the depression (‘‘sulcus’’) on the head completely (‘‘plena’’) extending across the vertex from one side of the head to the other.

Diagnosis. Noticeable external differences between E. (O.) plenasulca and other species of the subgenus include: the subquadrate shape of the labial palpus, the elongate cone shape of the maxillary palpus, the broad apex of the protibia, and the broad medial fossa on the mesotibia. Epuraea (Orthopeplus) plenasulca is also unique in the structure of the female genitalia, in particular the small tubular shape and oblique placement of the gonostyli, the degree of separation of the basal indentation of the gonocoxite, and relatively small compact size of the gonocoxite in toto. Notable intraspecific character variation includes the number of teeth present on the protibia and mesotibia apices.

Distribution. The species is known from southcentral Mexico ( Fig. 32 ).

Figures

Figs. 1–3. Dorsal aspect of head. 1) Epuraea (O.) quadricollis; 2) E. (O.) setosa; 3) E. (O.) plenasulca. Figs. 4–6. Labial palpus. 4) Epuraea (O.) quadricollis; 5) E. (O.) setosa; 6) E. (O.) plenasulca. Figs. 7–9. Maxillary palpus. 7) Epuraea (O.) quadricollis; 8) E. (O.) setosa; 9) E. (O.) plenasulca. Figs. 10–12. Prosternal process, lateral view. 10) Epuraea (O.) quadricollis; 11) E. (O.) setosa; 12) E. (O.) plenasulca. Figs. 13–15. Pronotum. 13) Epuraea (O.) quadricollis; 14) E. (O.) setosa; 15) E. (O.) plenasulca. Figs. 16–18. Pygidium. 16) Epuraea (O.) quadricollis; 17) E. (O.) setosa; 18) E. (O.) plenasulca. Scale bars ¼ 0.25 mm for Figures 1–3, 0.1 mm for Figures 4–9, 0.4 mm for Figures 13–15, and 0.3 mm for Figures 16–18.

Fig. 32. Geographic distribution of the three species of E. (Orthopeplus). The stippled regions indicate the presumed distributions of each species. The question mark indicates the likely location of the Texas ‘‘state only’’ record for E. (O.) quadricollis.