Hydraena ambra, 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 : 19-21

Hydraena ambra , new species

( Figs. 10 , 12 , 388 , 431 )

Type material. Holotype (male): Eastern Highlands Province: Wanitabi Valley, nr. Okapa , ex muddy gravel banks of small shaded stream, 1524 m, 6° 32' S, 145° 37' E, 5 ii 1965, M. E. Bacchus (MEB 177a) ( NHM) . Paratypes (276): Eastern Highlands Province: Akameku-Brahmin, Bismarck Range , 700 m, 5° 52.754' S , 145°

23.209' E, 24 xi 2006, Balke & Kinibel ( PNG 109) (1 ZSM); Marawaka, Ande , 1700 m, 7° 1.697' S, 145° 49.807' E , 8 xi 2006, Balke & Kinibel ( PNG 86) (25 MCZ, NHM, NMW, PNG, ZSM); Marawaka, Ande ,, 1700–1800 m, 7° 1.697' S, 145° 49.807' E , 9 xi 2006, Balke & Kinibel ( PNG 87) (2 ZSM); Okapa , ex muddy gravel banks of fast, clear stream, 1524 m, 6° 32' S, 145° 37' E , 9 ii 1965, M. E. Bacchus (MEB 183) (1 NHM); Okapa , under stones in small river, 1524 m, 6° 32' S, 145° 37' E , 10 ii 1965, M. E. Bacchus (MEB 186) (8 NHM); Purosa Valley, nr. Okapa , on submerged stones, [GE est.] 1500–1700 m, 6° 32' S, 145° 37' E , 8 ii 1965, M. E. Bacchus (MEB 182a) (2 NHM); Umg. [=environs of] Joginofi [?=Iganofi], Mukafanka River , [GE est.] 1700–1900 m, 6° 17' S, 145° 41' E , 13 vi 1979, W. G. Ullrich (6 MHNG); Umg. [=environs of] Kainantu, Onerunka , [GE est.] 1500–1700 m, 6° 17' S, 145° 52' E , 3 ii 1980, W. G. Ullrich (2 MHNG); same locality , 16 ii 1980, W. G. Ullrich (16 MHNG); same locality , 24 ii 1980, W. G. Ullrich (8 MHNG); Umg. [=environs of] Onerunka, Ramu River , [GE est.] 1500–1700 m, 6° 20' S, 145° 47' E , 13 vi 1979, W. G. Ullrich (14 MHNG); same locality , 18 vi 1979, W. G. Ullrich (1 MHNG); same locality , 9 xii 1979, W. G. Ullrich (7 MHNG); same locality , 1–30 iii 1980, W. G. Ullrich (3 MHNG); Waisa, nr. Okapa , in holes in partly burnt and decayed logs in small fast river, 1524 m, 6° 38' S, 145° 32' E , 15 ii 1965, M. E. Bacchus (MEB 192) (14 NHM); Waisa, nr. Okapa , in holes under stones in small fast river, 1524 m, 6° 38' S, 145° 32' E , 15 ii 1965, M. E. Bacchus (MEB 192a) (24 NHM); Wanitabi Valley, nr. Okapa , ex dead leaves caught among rocks in small swift river, 1372 m, 6° 32' S, 145° 37' E , 5 ii 1965, M. E. Bacchus (MEB 171b) (3 NHM); Wanitabi Valley, nr. Okapa , ex muddy gravel banks of small shaded stream, 1524 m, 6° 32' S, 145° 37' E , 5 ii 1965, M. E. Bacchus (MEB 177a) (17 NHM); Wanitabi Valley, nr. Okapa , on partly rotted floating logs, 1524 m, 6° 32' S, 145° 37' E , 5 ii 1965, M. E. Bacchus (MEB 176a) (1 NHM); Wapi Creek, Kimiagomo, Okapa , ex debris and submerged logs in creek, 1900 m, 6° 25' S, 145° 34' E , 9 viii 2005, K. Sagata (WB 123) (4 ZSM); Gulf Province: Marawaka, Mala , 1400 m, 7° 5.664' S, 145° 44.467' E , 11 xi 2006, Balke & Kinibel ( PNG 90) (4 ZSM); Madang Province: Simbai area , 1200 m, 5° 13.389' S, 144° 37.285' E , 10 iii 2007, Kinibel ( PNG 152) (3 ZSM); Morobe Province: ca. 10 km S Garaina Saureri , 1600 m, 7° 55' S, 147° 5' E , 24 iii 1998, A. Riedel (1 NMW); 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) (4 NHM); Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, 1220 m, 6° 48' S, 146° 48' E , 6 i 1965, M. E. Bacchus (MEB 140a) (2 NHM); Herzog Mts., Vagau [Wagau], ex gravel banks of small stream in dense primary forest, 1680 m, 6° 48' S, 146° 48' E , 12 i 1965, M. E. Bacchus (MEB 149a) (20 NHM); Herzog Mts., Vagau [Wagau], ex leaves caught among rocks in small stream in dense primary forest, 1680 m, 6° 48' S, 146° 48' E , 12 i 1965, M. E. Bacchus (MEB 149) (4 NHM); Kaindi ( Wau ), [GE est.] 1200–1400 m, 7° 20' S, 146° 42' E , 6 xii 1978, L. Deharveng (2 MHNG); Lae–Bulolo road, Gurakor Creek , ex gravel banks, [GE est.] 900–1100 m, 6° 50' S, 146° 37' E , 30 xii 1964, M. E. Bacchus (MEB 133) (3 NHM); Markham Valley, Gusap , 90 miles NW of Lae, ex small muddy pools in almost dry stream bed, much algae, 305 m, 5° 59' S, 146° 5' E , 27– 30 i 1965, M. E. Bacchus (MEB 158) (1 NHM); Western Highlands Province: Kundum , 1400 m, 5° 16.096' S, 144° 27.869' E , 3 iii 2007, Kinibel ( PNG 142) (22 MCZ, NHM, NMW, PNG, ZSM); Simbai , 1800–2000 m, 5° 14.276' S, 144° 28.741' E , 1 iii 2007, Kinibel ( PNG 138) (51 MCZ, NHM, NMW, PNG, ZSM) .

Differential diagnosis. Quite similar in dorsal habitus to H. ambroides and H. ambripes ( Figs. 10 , 11 , 14 ); differing from H. ambroides by the bicolored head, the less strongly punctate dorsum, and the larger size (ca. 1.82 vs. 1.71 mm); differing from H. ambripes by the confluent pronotal foveae PF2, the differently shaped pronotum (PA greater than PB), the longer elytra, and the larger size (ca. 1.82 vs. 1.76 mm). Males of H. ambra are distinguished from males of both compared species by the widened mesotibiae. The male genitalia of the three species ( Figs. 12, 13 , 16 ) clearly show a relationship; among other differences, in H. ambra the left paramere differs from that of H. ambripes , and the right paramere differs from that of H. ambroides .

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.82/0.75; head 0.30/0.38; pronotum 0.41/0.50, PA 0.42, PB 0.39; elytra 1.11/0.75. Dorsum amber colored, head bicolored, frons darker than clypeus and labrum, legs light brown, maxillary palpi testaceous.

Frons punctures ca. 1xef; interstices shining, 1–3xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctate, shining; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; lateral margins turning outward slightly at posterior angles; punctures on disc ca. 1xpd those of frons, interstices shining, 1–3xpd, punctures denser at anterior; PF1 united to form shallow transverse impression across anterior 1/3 of pronotal disc; PF2 well impressed, oval, oblique, very shallowly confluent in middle, conjointly forming U-shaped impression; PF3 and PF4 moderately deep.

Elytra distinctively humped just behind midlength, at summit of posterior declivity; lateral margins evenly arcuate; on basal 1/3 punctures ca. 1xpd largest pronotal punctures, a few random, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2xpd, as are interstices between punctures of a row. Apices in dorsal aspect very 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. 4/1.5/6/5. P1 narrow, not laminate; median carina sinuate in profile. P2 raised, l/w ca. as 3/2, sides slightly converging toward apex, apex joined to raised mesoventral intercoxal process. Plaques narrow, slightly arcuate, slightly converging toward one another anteriorly, weakly raised, weakly carinate laterally, located at sides of deep, median depression. Metaventrite with short midlongitudinal ridge between mesoventral intercoxal process and median depression, also with longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS and adjacent area on first ventrite conjointly forming shallow concavity; AIS width at straight posterior margin ca. 1.5x P2. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slender, straight. Mesotibia slightly widened on medial surface near distal 2/3. Metatibia slender, straight. Abdominal apex symmetrical. Female tergite X, gonocoxite, and spermatheca as illustrated ( Fig. 388 ).

Etymology. Named in reference to the color and transparency of the cuticle.

Distribution. With a wide geographical distribution, present in six Areas; usually collected at 1200 m or higher ( Fig. 431 ).

Figures

FIGURE 10. Hydraena ambra, holotype, dorsal and lateral habitus, and venter.

FIGURE 11. Hydraena ambripes, holotype, dorsal and lateral habitus, and venter.

FIGURE 14. Hydraena ambroides, holotype, dorsal and lateral habitus, and venter.

FIGURES 12–13. Aedeagi of holotypes. 12. H. ambra. 13. H. ambripes.

FIGURES 388–391. Female tergite X, gonocoxite, and spermatheca of Hydraena species.

FIGURES 431–434. Geographical distributions of Hydraena species.

FIGURES 16–17. Aedeagi of holotypes. 16. H. ambroides. 17. H. sagatai.