Hydraena johncoltranei, 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 : 141-142

Hydraena johncoltranei , new species

( Figs. 263 , 265 , 555 )

Type Material. Holotype (male): National Capital District, Varirata NP, 600 m, 9° 26.13' S, 147° 22.09' E, 16 xii 2007, Balke & Sagata ( PNG 159) ( ZSM) . Paratypes (10): Madang Province: Keki– Sewan , Adelbert Mts., 700 m, 4° 41.802' S, 145° 25.46' E, 30 xi 2006, Binatang Boys ( PNG 120) (4 ZSM) ; National Capital District, Same data as holotype (6 MCZ, NHM, NMW, PNG, ZSM) .

Differential Diagnosis. Very similar to and, based on the male genitalia, the sister species of, H. fundacta ( Figs. 262 , 263 ). Both species are differentiated from other members of the Fundarca group by the metaventral plaques, which are either reduced to tiny oval bumps ( H. johncoltranei ), or totally absent ( H. fundacta ). In addition, both species have P1 slightly wider than laminate, and, in males, the abdominal apex is modified. The male genitalia of each species have a greatly enlarged basal ring; the distal piece, while similar in basic plan, has distinct differences in the two species ( Figs. 264, 265 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.33/0.59; head 0.18/0.33; pronotum 0.34/0.49, PA 0.36, PB 0.45; elytra 0.80/0.59. Dorsum of head with frons and clypeus dark brown to piceous, labrum testaceous; pronotum light brown to testaceous around dark brown to piceous, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 6/12/5; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining.

Frons punctures ca. 1xef near eyes, slightly smaller and sparser medially; interstices shining, 2–3xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. 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, except margin very weakly produced in middle, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc slightly larger than largest frons punctures, interstices shining, ca. 2–4xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF1, PF2 and PF4 absent; PF3 shallow, wide.

Elytra widest slightly anterior to midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1/3 punctures ca. 1xpd of largest pronotal punctures, but shallower, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1–3xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 4/0.5/1/6. P1 0.5x P2; median carina nearly straight in profile, very slightly arcuate between coxae. P2 markedly concave, length/width ca. 5/4, sides very slightly diverging toward blunt, slightly concave apex. Plaques minute, nearly imperceptible bumps, at sides of median depression. Metaventrite between mesocoxae slightly sloping, confluent with tip of P2. AIS width at straight posterior margin slightly greater than P2. All legs of moderate length. Profemur (male) without tubercle on ventral margin near basal 1/3; protibia very slightly arcuate, slender, gradually increasing in width from base to apex. Meso- and metatibia straight, slender. Abdominal apex (male) enlarged, asymmetrical; last tergite with oblique ridge on dorsal surface. Aedeagus as illustrated ( Fig. 265 ).

Etymology. Named in honor of the jazz great, the supreme saxophonist John Coltrane.

Distribution. A very disjunct and curious distribution: one locality each in the Adelbert Mts. (Area 5, 700 m), and the Varirata National Park (Area 11, 600 m) ( Fig. 555 ).

Figures

FIGURE 262. Hydraena fundacta, holotype, dorsal and lateral habitus, and venter.

FIGURE 263. Hydraena johncoltranei, holotype, dorsal and lateral habitus, and venter.

FIGURES 264–265. Aedeagi of holotypes. 264. H. fundacta. 265. H. johncoltranei.

FIGURES 555–558. Geographical distributions of Hydraena species.