Oosternum bacharenge, Deler-Hernandez, Albert, Cala-Riquelme, Franklyn & Fikacek, Martin, 2014

Deler-Hernandez, Albert, Cala-Riquelme, Franklyn & Fikacek, Martin, 2014, A review of the genus Oosternum Sharp of the West Indies (Coleoptera: Hydrophilidae: Sphaeridiinae), Deutsche Entomologische Zeitschrift 61 (1), pp. 43-63 : 43

Oosternum bacharenge sp. n. Figs 3-42030405461

Type-locality.

Dominican Republic, Hatomayor province: Parque Nacional Los Haitises, 19°1 ’4.26” N, 69°37 ’17.24” W, 250 m, W of Sabana de la Mar.

Type-specimens

(1 spec.). Holotype dry mounted, with genitalia mounted in Euparal on a microslide pinned below the specimen. Original label: "DOM REP: Hatomayor province, Par. Nac. Los Haitises W. of Sabana de la Mar, 01.iv.1992, M. A. Ivie, D. S. Sikes & W. Lanier, 19°1 ’4.26” N, 69°37 ’17.24” W, elevation 250 m, [printed] / Holotype, Oosternum bacharenge sp. n., Deler-Hernández & Fikáček det. 2013 [red, printed]" (WIFP).

Diagnosis.

Body widest ca. at midlength. Lateral margin of pronotum angulate. Pronotal punctation uniform in size, moderately dense consisting of small rasp-like punctures. Pronotal interstices without microsculpture. Mesal part of prosternum not divided from lateral portions. Lateral margin of antennal grooves rounded. Elytral interval 2 narrower than interval 3, lower than intervals 1 and 3, reaching elytral apex. Elytral intervals 5, 7 and 9 as convex as adjacent intervals. Elytral interstices shiny, without microsculpture. Preepisternal plate narrow, suboval, 2.8 × longer than wide. Interstices of median part of metaventrite without microsculpture, shiny. Anterolateral ridges of metaventrite meeting together and bent posteriad mesally. Parameres 0.8 × as long as phallobase, bearing two short setae apically. Median lobe ca. as long as parameres, nearly parallel-sided, bottle-shaped apically. Membranous lateral projections of median lobe absent.

Description.

Habitus. Body elongate oval, gradually narrowing posteriad; total length /total widht ratio = 1.6. Length: 1.4 mm; width: 0.84 mm.

Coloration. Coloration of dorsal side of head, pronotum and elytra dark brown. Ventral side brown.

Head. Clypeus with sparse punctation consisting of fine punctures, each puncture bearing fine decumbent seta; setae pale; interstices without microsculpture; anterior margin of clypeus slightly concave. Frons with moderately dense punctation, consisting of coarse, crescent-like punctures, punctures of same shape medially and laterally; interstices without microsculpture. Eyes moderately large. Mentum 1.8 × wider than long, anterior margin slightly emarginate; anteromedian part not distinctly impressed; with sparse punctation consisting of small and isolated, nearly indistinct punctures bearing minute setae; interstices with very fine microsculpture, opaque. Submentum without poriferous disc-like fields. Maxillary palpus with palpomeres 2 and 4 ca. 1.5 × longer than palpomere 3. Antenna with 9 antennomeres; scapus shorter than antennomeres 2-6 combined.

Prothorax. Pronotum evenly convex forming continuous curve with elytra in lateral view. Lateral margin of pronotum angulate, with narrow marginal bead. Pronotal punctation uniform in size, moderately dense, slightly denser than that on frons, consisting of small, rasp-like punctures similar on whole surface of pronotum; all punctures bearing long setae; interstices without microsculpture. Median portion of prosternum not elevated and demarcated from lateral portions, median carina of prosternum narrow, projecting more anteriad mesally than anterior margin of median portion, with anterior portion elevated into small tooth in lateral view. Postero-mesal projection with deep notch. Antennal groves moderately large. Lateral margin of antennal grooves rounded.

Mesothorax. Scutellar shield bearing a few tiny punctures; interstices without microsculpture. Elytral punctures coarse, shallowly impressed, rounded to slightly transverse. Serial punctures small; transverse; sparsely arranged, with minute setae (indistinct under binocular microscope). Interval 2 narrower than interval 3, lower than intervals 1 and 3, reaching elytral apex, intervals 5, 7 and 9 as convex as adjacent intervals. Elytral interstices shiny, without microsculpture. Preepisternal plate narrow, suboval, 2.8 × longer than wide, widely attached to metaventrite; posterior part of preepisternal elevation slightly overlapping over anterior margin of metaventrite; median part flat; bearing sparsely arranged shallow setiferous punctures; interstices without microsculpture.

Metathorax. Metaventrite distinctly longer than preepisternal elevation of mesothorax, median portion markedly differing from lateral portion in punctation and microsculpture; punctation of median portion sparse, consisting of minute punctures, interstices without microsculpture, shiny. Anterolateral ridges bent posteriad along lateral margin of metaventrite, concave laterally, meeting together and proyecting posteriad mesally. Anterior margin of metaventrite not crenulate.

Abdomen. Ventrite 1 with additional longitudinal ridges laterally. Ventrites 2-5 without longitudinal ridges; posterior margin of all ventrites lacking denticles.

Male genitalia. Aedeagus 0.48 mm long, parameres 0.8 × longer than phallobase. Parameres continuously narrowing apicad, bearing two short setae apically. Phallobase wide, 2 × longer than wide. Median lobe ca. as long as parameres, nearly parallel-sided, with wide apical projection. Membranous lateral projections of median lobe absent. Gonopore absent.

Etymology.

The new species is dedicated to the Dominican radio station El Bacharenge, a source of the Caribbean music for the first author during his studies in the Czech Republic.

Distribution.

Oosternum bacharenge sp. n. is a Hispaniolan endemic species currently only known from the type locality in the northeastern part of the Dominican Republic (Hato Mayor province) (Fig. 61).

Habitat.

Based on the label data, the type specimens was collected in litter between tree buttresses in the rain forest.