Hydraena manuloides Perkins 2011, new species

Hydraena manuloides, new species

(Figs. 23, 25, 440)

Type Material. Holotype (male): Central Province: Port Moresby – Brown River road, ex gravel banks of small fast running stream, [GE est.] 50–100 m, 9° 24' S, 147° 14' E, 15 iii 1965, M. E. Bacchus (MEB 199a) (NHM). Paratypes (263): Central Province: Kokoda, under stones, river side, 365 m, 8° 39' S, 147° 15' E, 1–30 viii 1933, L. E. Cheesman (577) (22 NHM); nr. Port Moresby, Sogeri Plateau, Musgrave River, ex dead leaves caught among rocks, [GE est.] 100–200 m, 9° 46' S, 147° 41' E, 16 iii 1965, M. E. Bacchus (MEB 200b) (5 NHM); Port Moresby – Brown River road, ex gravel banks of large slow muddy river, [GE est.] 50–100 m, 9° 24' S, 147° 14' E, 15 iii 1965, M. E. Bacchus (MEB 198) (5 NHM); Port Moresby – Brown River road, ex gravel banks of small fast running stream, [GE est.] 50–100 m, 9° 24' S, 147° 14' E, 15 iii 1965, M. E. Bacchus (MEB 199a) (19 NHM); Madang Province: Finisterre Mts., Naho River Valley, Budemu, ex gravel banks of large river, 1264 m, 5° 56' S, 146° 40' E, 18 x 1964, M. E. Bacchus (MEB 61) (1 NHM); Ramu Valley, Sare River, 4 km N Brahman, [GE est.] 130–150 m, 5° 39' S, 145° 22' E, 16 iv 1991, D. Larson (43 MCZ); Sepik-Ramu Basin, Mom Creek, substrate of smooth cobbles set in coarse sand, loosely packed, 20% shaded, water shallow, 170 m, 5° 45' S, 145° 20' E, 1 vi–30 vii 1988, D. Dudgeon (72 NMW); Morobe Province: c. 3 m. Lae–Busu road, ex gravel banks of small swift river, [GE est.] 50–70 m, 6° 41' S, 147° 0' E, 21 i 1965, M. E. Bacchus (MEB 155a) (70 NHM); Lae, Umg. [=environs of] Oomsis, Buang River, [GE est.] 20–30 m, 6° 53' S, 146° 57' E, 15 vii 1979, W. G. Ullrich (23 MHNG); Oro Province: Northern District, Tanbugal Afore village, [GE est.] 300–500 m, 9° 7' S, 148° 23' E, 16 viii 1975, R. W. Hornabrook (3 NMNZ).

Differential Diagnosis. Very similar to H. manulea in habitus, size, and shape of the male protibia (Figs. 22, 23). Reliable determinations will be based on close examination of the male genitalia (Figs. 24, 25); refer to the differential diagnosis of H. manulea.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.42/0.58; head 0.25/0.33; pronotum 0.34/0.42, PA 0.36, PB 0.38; elytra 0.85/0.58. Dorsum of head piceous; pronotum brown in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 6/13/3; elytra dark brown; legs and maxillary palpi light brown, tip of palpus not darker.

Frons punctures ca. 1xef, slightly larger near eyes than medially; interstices shining, 1–4xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, median 2/3 of anterior margin emarginate; punctures on disc ca. 1xpd those of frons, interstices shining, 1–4xpd, punctures slightly larger and denser at anterior and posterior; PF1 absent; PF2 very shallow, obsolete; PF3 moderately deep; PF4 absent.

Elytra with 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. 1–2xpd, as are interstices between punctures of a row, a few punctures subserial. 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. 3/2/6/2. P1 laminate; median carina sinuate in profile. P2 raised, l/w ca. 2/1, sides converging toward blunt apex. Plaques moderately wide, converging anteriorly, roundly raised, located at sides of deep, median depression. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin slightly greater than P2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slightly arcuate, distal 1/3 slightly widened on anterior surface, medial margin apically with cluster of very short spines. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 25).

Etymology. Named in reference to the relationship with H. manulea.

Distribution. With a wide distribution pattern in eastern PNG, but without records from Area 1; found in Areas 2, 3, 5, 7, 8 and 11; elevation range 20–1265 m, but with only one record above 500 m (Fig. 440).