Hydraena altapapua, 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 : 57

Hydraena altapapua , new species

( Figs. 83 , 85 , 464 )

Type Material. Holotype (male): Southern Highlands Province: Sopulkul , 30–35 km NE Mendi, 2680 m, 6° 2.944' S, 143° 46.485' E, 16 vi 2006, John ( PNG 79) ( ZSM) . Paratypes (32): Eastern Highlands Province: Akameku– Brahmin , Bismarck Range, 2400 m, 5° 55.615' S, 145° 22.699' E, 23 xi 2006, Balke & Kinibel ( PNG 107) (3 ZSM) ; Akameku– Brahmin , Bismarck Range ,, 2200 m, 5° 56.801' S, 145° 22.238' E, 23 xi 2006, Balke & Kinibel ( PNG 106) (4 ZSM) ; Madang Province: Sepik-Ramu Basin , Cold Creek, montane stream tumbled down among moss-covered rocks which alternated with short sandy runs in more level sections, almost completely shaded, [GE est.] 2000–2200 m, 5° 45' S, 145° 8' E, 7 vi 1988, D. Dudgeon (2 NMW) ; Southern Highlands Province: Same data as holotype (23 MCZ, NHM, NMW, PNG, ZSM) .

Differential Diagnosis. Differentiated from other members of the Tetana group by the large size (ca. 2.03 mm), the comparatively deep pronotal foveae PF2, the convex elytra, and the comparatively small (for this group) and widely spaced metaventral plaques that are more widely spaced posteriorly than anteriorly ( Fig. 83 ). The male genitalia distinctly differ from that of other members of the Tetana group ( Fig. 85 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 2.03/0.83; head 0.31/0.44; pronotum 0.48/0.58, PA 0.48, PB 0.50; elytra 1.25/0.83. Dorsum piceous; legs and maxillary palpi dark brown.

Frons punctures ca. 1–2xef, slightly larger near eyes than medially; interstices shining, 1–3xpd, anterolateral angles microreticulate. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate, dull. Genae raised, shining, without posterior ridge, posteromedially with small pit into which apicomedian process of prosternum fits when head retracted. Pronotum cordiform, median 2/3 of anterior margin emarginate; punctures on disc ca. 1xpd those of frons, interstices shining, 2–3xpd, punctures slightly larger and denser at anterior and posterior; PF1 extremely shallow or absent; PF2 moderately deep, posterior margins obsolete, shallowly confluent; PF3 deep; PF4 absent.

Elytra transversely convex, summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1/3 punctures ca. 1xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2–3xpd, as are interstices between punctures of a row, a few punctures subserial. 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. 4/3/10/4. P1 laminate; median carina sinuate in profile. P2 raised, l/w ca. 2/1, sides slightly diverging toward blunt apex. Plaques moderately large, converging anteriorly, twice as widely separated posteriorly as anteriorly, weakly raised. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin very slightly wider than P2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slightly arcuate, distal 1/3 weakly widened on anterior surface, moderately long spine on medial surface at ca. distal 1/3. Meso- and metatibia straight. Meso- and metatarsi with short setae along lower margin. Fifth abdominal ventrite simple. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated ( Fig. 85 ).

Etymology. Named in reference to the high elevation at which this species lives; the 2680 m locality record is the highest known for PNG Hydraena .

Distribution. Currently known from eastern Area 1; elevation range 2200–2680 m ( Fig. 464 ).

Figures

FIGURE 83. Hydraena altapapua, holotype, dorsal and lateral habitus, and venter.

FIGURES 84–85. Aedeagi of holotypes. 84. H. aulaarta. 85. H. altapapua.

FIGURES 463–466. Geographical distributions of Hydraena species.