Hydraena ollopa, 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 : 79

Hydraena ollopa , new species

( Figs. 131 , 133, 492 )

Type Material. Holotype (male): Western Highlands Province: Kundum , 1400 m, 5° 16.096' S, 144° 27.869' E, 3 iii 2007, Kinibel ( PNG 142) ( ZSM) . Paratypes (64): Western Highlands Province: Same data as holotype (21 MCZ, NHM, NMW, PNG, ZSM); Lugup River, 1700 m, 5° 17.237' S, 144° 28.214' E, 4 iii 2007, Kinibel ( PNG 143) (43 MCZ, NHM, NMW, PNG, ZSM) .

Differential Diagnosis. Very similar in external characters to H. mercuriala ( Figs. 130 , 131 ). Reliable determinations will require examination of the distinctively different male genitalia ( Figs. 132, 133).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.95/0.82; head 0.32/0.44; pronotum 0.45/0.53, PA 0.47, PB 0.46; elytra 1.19/0.82. Dorsum piceous; legs brown; maxillary palpi brown except distal 1/2 of last palpomere darker.

Frons moderately coarsely, moderately densely punctate, punctures ca. 1–2xef; interstices shining, 0.5–5xpd, punctures sparser on disc. Clypeus microreticulate laterally, finely, sparsely punctate medially. Mentum very sparsely very finely punctulate, strongly shining, each puncture with moderately long recumbent seta; postmentum medially micropunctulate, otherwise finely sparsely punctate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2/3 of anterior margin emarginate; punctures on disc ca. 1xpd largest punctures of frons, interstices shining, 1–2xpd, punctures slightly larger and denser at posterior; PF1 very shallow; PF2 moderately deep, very shallowly confluent; PF3 deep; PF4 moderately deep.

Elytra with summit of posterior declivity at or very near midlength; lateral explanate 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. 1–2xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 4/2/10/6. P1 laminate; median carina sinuate in profile. P2 raised, l/w ca. 3/2, sides slightly converging toward apex. Plaques moderately wide, flat, converging slightly from posterior to anterior, located at sides of deep median depression. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.6x P2. All legs long and slender. Profemur (male) with tubercle near trochanter; protibia straight, except subapically bent, forming process on medial surface that, when leg flexed, opposes tubercle of femur. Mesotibia slightly arcuate, medial surface subapically widened and with small tubercle. Metatibia moderately arcuate in distal 1/2; metatarsus with large brush of setae on ventral surface of basal tarsomeres. Abdominal apex slightly asymmetrical; last tergite (male) deeply notched. Aedeagus ( Fig. 133) with large, very complicated distal piece, best viewed in dorsal aspect; left paramere very large, sinuate.

Etymology. The specific epithet is an anagram of Apollo; the mythological Apollo was the brother of Mercury. The name is to be treated as a noun.

Distribution. Currently known from two very narrowly separated localities in north central Area 1; elevations 1400 m and 1700 m ( Fig. 492 ).

Figures

FIGURE 130. Hydraena mercuriala, holotype, dorsal and lateral habitus, and venter.

FIGURE 131. Hydraena ollopa, holotype, dorsal and lateral habitus, and venter.

FIGURES 491–494. Geographical distributions of Hydraena species.