Hydraena carmelita, 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 : 129-130

Hydraena carmelita , new species

( Figs. 238 , 240, 542 )

Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex dead leaves in small stream in dense forest, 1220 m, 6° 48' S, 146° 48' E, 6 i 1965, M. E. Bacchus (MEB 139) ( NHM) . Paratypes (4): Morobe Province: Same data as holotype (1 NHM); NE, McAdam Park , [GE est.] 700–900 m, 7° 16' S, 146° 40' E, 29 viii 1968, J. Balogh (No. NG –W–B.38) (3 ISNB) .

Differential Diagnosis. Differing from the other maculate members of the Incisiva group by the carmel-like dorsal color and small size (ca. 1.61 mm); otherwise very similar ( Fig. 238 ). The aedeagus is very distinctive and should be examined for reliable determinations ( Fig. 240).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.61/0.66; head 0.23/0.36; pronotum 0.41/0.55, PA 0.41, PB 0.51; elytra 0.97/0.66. Dorsum of head with frons dark reddish brown, clypeus brown, labrum testaceous; pronotum testaceous around light brown rectangular macula, ratios of color bands, as measured in midline, ca. 6/14/7; elytra dark brown; legs light brown; maxillary palpi light brown to testaceous, tip not darker. Dorsum shiny.

Frons punctures ca. 1–2xef near eyes, smaller and much sparser medially; interstices shining, 1–2xpd laterally, ca. 2–6xpd medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate, weakly shining. Genae very slightly raised, shining, without posterior ridge. Pronotum subtrapezoidal, ca. median 3/4 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate between midlength and posterior angle; punctures on disc slightly smaller than largest frons punctures, interstices strongly shining, ca. 2–5xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF1, PF2 and PF4 absent; PF3 shallow.

Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1/3 punctures slightly smaller than largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2–3xpd, as are interstices between punctures of a row. 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. 4/2/7/5. P1 laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P2 markedly concave, length slightly greater than width, sides very slightly converging toward blunt apex. Plaques roundly slightly raised, very slightly converging anteriorly, at sides of median depression. Metaventrite between mesocoxae flat. AIS width at straight posterior margin ca. 1.5x P2. All legs of moderate length. Profemur (male) without tubercle next to trochanter; protibia slightly arcuate, medial margin increasing in width from base to distal 1/4, then excavate to apex, few large spines at base of excavation, and contiguous row of very short spines along excavation. Mesotibia straight. Metatibia straight, very weakly emarginate on medial margin in distal 1/2. Abdominal apex symmetrical; last tergite (male) with small apicomedian notch. Aedeagus as illustrated ( Fig. 240).

Etymology. Carmen (sing, charm) plus mellita (honey sweet); named in reference to the rich caramel-like dorsal coloration.

Distribution. Currently known from two localities in Area 6: Herzog Mts. (1220 m) and McAdam National Park (700–900 m) ( Fig. 542 ).

Figures

FIGURE 238. Hydraena carmellita, holotype, dorsal and lateral habitus, and venter.

FIGURES 539–542. Geographical distributions of Hydraena species.