Hydraena buquintana, Perkins, 2011

Perkins, Philip D., 2011, New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944, Zootaxa 2944 (1), pp. 1-417 : 126-127

Hydraena buquintana , new species

( Figs. 231 , 233 , 513 )

Type Material. Holotype (male): Western Highlands Province: Mt. Hagen town area, 1600 m, 5° 51.491' S, 144° 20.194' E, 7 xii 2006, Balke & Kinibel ( PNG 130) ( ZSM) . Paratypes: Same data as holotype (1 male ZSM) .

Differential Diagnosis. Differentiated from other members of the Quintana group by the larger size (ca. 1.33 vs. 1.23 mm), the denser pronotal punctation, the more regularly serial discal elytral punctures, the more strongly microreticulate frons, the narrower testaceous borders around the pronotal fascia, and the slightly longer dorsal setae ( Fig. 231 ). Males have the abdominal ventrites modified similar to those of H. quintana (SEM Figs. 356, 357 ). The male genitalia of all three species in the Quintana group distinctively differ from one another in the shapes of the processes of the distal piece ( Figs. 229, 232, 233 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.33/0.56; head 0.19/0.31; pronotum 0.33/0.45, PA 0.35, PB 0.42; elytra 0.82/0.56. Dorsum of head dark brown to piceous, lateral areas of clypeus slightly lighter; pronotum light brown in front of and behind dark brown to piceous, diffusely margined fascia, ratios of color bands, as measured in midline, ca. 5/12/5; elytra dark brown; legs light brown to testaceous; maxillary palpi testaceous, tip not darker. Dorsum moderately shining.

Frons punctures ca. 1xef near eyes, smaller and sparser medially; interstices 1–5xpd, microreticulate and dull laterally, shining medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum microreticulate, finely punctulate, dull. Postmentum concave, microreticulate, dull. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3/4 of anterior margin slightly arcuate to posterior, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc very fine and very sparse, slightly smaller than largest frons punctures, interstices shining, ca. 4–6xpd, punctures anteriorly and posteriorly slightly larger and denser than those on disc; PF1 and PF4 absent; PF2 very shallow, obsolete; PF3 moderately deep, wide.

Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1/3 some punctures subserial, ca. 1xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2–3xpd. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 3/2/7/4. P1 laminate; median carina sinuate in profile, slightly raised between coxae. P2 length/width ca. 5/3, sides very slightly diverging toward blunt, slightly raised apex. Plaques flat, lateral margins arcuate, at sloping sides of median depression, anteriorly tapering and slightly convergent. Metaventrite flat between mesocoxae. AIS width at straight posterior margin ca. equal P2. All legs of moderate length. Profemur (male) without tubercle on ventral margin; protibia very slightly arcuate, medial margin slightly widened in distal 1/2 and with row of short spines. Meso- and metatibia straight, slender. Abdominal apex markedly modified in males, similar to that of H. quintana (SEM Figs. 356, 357 , 361 ); 5th ventrite with oblique tubercle on each side of midline; 6th ventrite weakly concave. Aedeagus as illustrated ( Fig. 233 ).

Etymology. Named in reference to the size and relationship to H. quintana .

Distribution. Currently known only from the type locality, Mt. Hagen town area, in south central Area 1; elevation 1600 m ( Fig. 513 ).

Figures

FIGURE 231. Hydraena buquintana, holotype, dorsal and lateral habitus, and venter.

FIGURES 232–233. Aedeagi of holotypes. 232. H. ramuquintana. 233. H. buquintana.

FIGURES 511–514. Geographical distributions of Hydraena species.

FIGURES 352–357. Scanning electron micrographs of H. quintana.

FIGURES 358–363. Scanning electron micrographs of H. quintana (358–361) and H. otiarca (362–363).