Hydraena dilutipes Fairmaire

Hydraena dilutipes Fairmaire

Figs. 98 (habitus), 100, 101 (aedeagus), 275 (map)

Hydraena dilutipes Fairmaire 1898b: 468.

Type Material. Lectotype (male): Labels on lectotype: "Madag [illegible]; TYPE [red]; MUSEUM PARIS MADAGASCAR PERRIER DE LA BATHIE COLLECTION LEON FAIRMAIRE 1906; LECTOTYPE Hydraena dilutipes Fairmaire 1898, design. P. D. Perkins 2015 [red]". Two female paralectotypes: 1) " Hydraena dilutipes Farm Madag; MUSEUM PARIS MADAGASCAR PERRIER DE LA BATHIE COLLECTION LEON FAIRMAIRE 1906; PARALECTOTYPE Hydraena dilutipes Fairmaire 1898, design. P. D. Perkins 2015 [red]". 2) "Madag Perrier; MUSEUM PARIS MADAGASCAR PERRIER DE LA BATHIE COLLECTION LEON FAIRMAIRE 1906; PARALECTOTYPE Hydraena dilutipes Fairmaire 1898, design. P. D. Perkins 2015 [red]" (MNHN).

Specimens examined (883): Antananarivo, 18.158S 47.2104E Analamanga, Manankazo river by the bridge of RN4, medium size river over bedrock, elev. 1450 m, 18° 9' S, 47° 12' E, 21 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren (MAD14-75) (4 NHRS); Manakambahiny, in seepage over exposed granite cliff face, 18° 55' S, 47° 32' E, 12 i 1990, W. E. Steiner (28 USNM); Antsiranana, 14.4345S 49.7606E Sava Marojejy NP Camp II, wide river forming hygropetric rocks, wide river forming hygropetric rocks and rockpools, elev. 710 m, 14° 26' S, 49° 45' E, 9 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren (MAD14-54) (3 NHRS); 14.4369S 49.7749E Sava, Marojejy NP, 300m N from Camp I, upstream, waterhole with dead leaves next to the stream, elev. 490 m, 14° 44' S, 49° 46' E, 8 xi 2014, P. D.

Perkins (MAD14-50) (10 MCZ); 14.4369S 49.7749E Sava Marojejy NP 300m N from Camp I, upstream, waterhole with dead leaves next to the stream, elev. 490 m, 14° 26' S, 49° 46' E, 8 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren (MAD14-50) (22 NHRS); 14.5221S 49.7545E Sava, bridge 80km from Sambava, where tributary river enters Lokoho river, rockpools and sandy waterpools at river margin, elev. 120 m, 14° 31' S, 49° 45' E, 17 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren (MAD14-73) (9 NHRS); Antsaba, Galoko Mountains, hygropetric cascade, elev. 303 m, 13° 39' S, 48° 45' E, 1 xi–29 xii 2004, M. Balke (MD 016) (124 ZSMC; one male " MNCN AI-547 DNA specimen"); Diana: Antsaba: Ambolamena mountain, 4km SE Antsaba village,“Antohatea be Cascade ”, S 13.67593 E 48.75589, GB nets, sieves, aspirator, forceps: waterfall with hygropetric rocks, elev. 381 m, 13° 41' S, 48° 45' E, 27 xi 2012, J. Bergsten, R. Bukontaite, J.H. Randriamihaja & T. Ranarilalatiana (MAD12-29) (1 NHRS); Diana: Antsaba: Galoko mountains, S 13.60974 E 48.72175, sieves and aspirator: hygropetric rocks and water pools, elev. 263 m, 13° 37' S, 48° 43' E, 25 xi 2012, J. Bergsten, R. Bukontaite, J.H. Randriamihaja & T. Ranarilalatiana (MAD12-26) (1 NHRS); Forêt d' Antsahabe, 11.4 km 275° W Daraina, malaise trap, tropical dry forest, elev. 550 m, 13° 12' S, 49° 33' E, 12 xii 2003, B.L.Fisher (BLF 10117) (1 CAS); Forêt d'Anabohazo, 21.6 km 247° WSW Maromandia, malaise trap- in tropical dry forest, elev. 120 m, 14° 18' S, 47° 54' E, 11–16 iii 2001, Fisher, Griswold et al. (BLF 3336) (1 CAS); Marojejy NP, camp 2, hygropetric habitat, 14° 26' S, 49° 46' E, 30 x 2007, J. Stastny (1 NHRS); Montagne d'Ambre, Grande Cascade, elev. 740 m, 13° 34' S, 49° 10' E, 1 xi–30 xii 2004, M. Balke (MD 004) (20 ZSMC); Sambava: Marojejy NP, Camp 2 long waterfall along smooth rock area (hygropetric), N:-14.43400, E:49.75633, elev. 717 m, 14° 26' S, 49° 45' E, 7 xii 2006, Isambert et al. (P57 Bi 12) (8 NHRS); Sava, Marojejy NP, 800m N from Camp I, Humbert waterfall; 14.4333S 49.773E, waterfall, elev. 550 m, 14° 26' S, 49° 46' E, 8–12 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren (MAD14-48) (12 NHRS); Marojejy NP, 800m N from Camp I, Humbert waterfall; 14.4333S 49.773E, ex. bedrock pools at side of waterfall, elev. 550 m, 14° 26' S, 49° 46' E, 8 xi 2014, P. D. Perkins (MAD14-48) (256 MCZ); Atsinanana, NP Midongy, 23° 30' S, 46° 55' E, 17 viii 2011, (collector not given on label) (4 NHRS); Fianarantsoa, 20.1711S 47.091E, Amoron'i, ManiaUpstream Talaviana river from the crossing with RN7, 37km S of Antsirabe, rocky river with sandy bottom and some hygropetric rocks, elev. 1360 m, 20° 10' S, 47° 5' E, 1 xi 2014, P. D. Perkins (MAD14-01) (1 MCZ); 21.2581S 47.4213E, Vatovavy-Fitovinany, Ranomafana NP, Namorona river by bridge at park entrance, rockpools and hygropetric sites by river, elev. 890 m, 21° 15' S, 47° 25' E, P. D. Perkins (MAD14-09) (37 MCZ); 7 km W Ranomafana, from seepage over sunlit rock at river, montane rainforest, elev. 900 m, 21° 16' S, 47° 25' E, 6 ix 1993, W. E. Steiner & M. Stebbins (32 USNM); same locality, W. E. Steiner & J. E. Cadle (41 USNM); 7 km W Ranomafana, on seepage over exposed rocks at bank of Namorona River, elev. 900 m, 21° 16' S, 47° 25' E, 1–7 iii 1990, W. E. Steiner (44 USNM); Ionilahy (Fianarantsoa), first left affl. of Riv. Ionilahy upstr. railroad bridge to Manakara, 200 m, 23.5°C, 0.088 mS/cm; hygropetric, elev. 200 m, 21° 43' S, 47° 38' E, 11 viii 2001, Gerecke & Goldschmidt (MD 20c) (4 NMW); Ionilahy (Fianarantsoa) Mahavavona, spring 3 Exp. NW, (hygropetric on rocks exposed to sun in rice field), elev. 284 m, 21° 42' S, 47° 38' E, 20 iv 2011, R. Gerecke (MD 218) (1 NMW); Namorona River, 7 km W Ranomafana, from semi-shaded temporary pond in montane rain forest, elev. 1100 m, 21° 15' S, 47° 25' E, 1–7 xi 1988, W. E. Steiner (55 USNM); Namorona River, 7 km W Ranomafana, on seepage over exposed rock at bank of Namorona River, elev. 900 m, 21° 16' S, 47° 25' E, 8– 21 x 1988, W. E. Steiner (38 USNM); Ranomafana, Namorona main river, rockpools, elev. 927 m, 21° 15' S, 47° 25' E, 1 xi–30 xii 2004, M. Balke (MD 029) (93 ZSMC); Vatovavy Fitovinany: Ranomafana NP: Namorona river by the bridge below park entrance: S 21.25809 E 0 47.42165, GB Nets & sieves, rockpools, elev. 920 m, 21° 15' S, 47° 25' E, 1 xi 2011, J. Bergsten, R. Bukontaite, T. Ranarilalatiana, & J.H. Randriamihaja (MAD11-09) (9 NHRS); Melaky: Tsingy de Bemaraha NP. S 18.75875 E 0 44.71648, elev. 112 m, 18° 46' S, 44° 43' E, 17 xii 2009, J. Bergsten, N. Jönsson, T. Ranarilalatiana, HJ. Randriamihaja (MAD09-68) (1 NHRS); Toliara, Andhahela (Tulear), Isaka, stream exp. W 1 km N from the vill., elev. 250 m, 24° 48' S, 46° 51' E, 7 ix 2001, Gerecke & Goldschmidt (MD 63) (1 NMW); Ifaty, under seaweed drift on sand beach, 23° 9' S, 43° 37' E, 19 ix 1993, W. E. Steiner & R. Andriamasimanana (1 USNM); Tsimelahy (Tulear), Riv. Antarantsa, ca. 1 km upstream from village, elev. 300 m, 24° 56' S, 46° 38' E, 4 ix 2001, Gerecke & Goldschmidt (MD 58) (20 NMW).

Differential Diagnosis. Closely related to H. dilutipoides, differing therefrom by the larger size (ca. 1.81 mm vs. 1.73), the more coarsely densely punctate pronotum, and having the elytral intervals strongly raised and forming unbroken lines. The plaques of H. dilutipoides are more widely separated, especially posteriorly, and more sharply rounded at the posterior edge. Males of both species have large metatibial brushes. The aedeagi also show a relationship, having a large, flat distal extension of the main piece; the complex gonopore bearing distal piece differs significantly in the two species (Figs. 100–102).

Description. Size: Lectotype (length/width, mm): body (length to elytral apices) 1.81/0.76; head width 0.43; pronotum 0.42/0.60, PA 0.44, PB 0.53; elytra 1.11/0.76. Dorsum dark brown, head darkest; legs brown; maxillary palpi brown to light brown, distal ½ of last palpomere darker. Mentum sparsely finely punctulate, shining; postmentum rugulose, dull. Genae raised, weakly rugulose, dull, without distinct posterior ridge.

Head and pronotum coarsely densely punctate, punctures of pronotum slightly larger than those of head; interstices narrow ridges, shining.

Pronotum slightly sinuate laterally; anterior margin straight behind eyes, emarginate behind frons; PF1 very shallow; PF2 shallow, very shallowly confluent medially forming weak U-shaped impression; PF3 moderately deep; PF4 absent.

Elytra weakly arcuate laterally; summit of posterior declivity near distal 2/3; lateral explanate margins moderately narrow; serial punctures deeply impressed, round, and closely spaced, slightly larger than pronotal punctures. Intervals raised, narrow, shining, ca. 0.5xpd. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming very shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/1/2/1.3. P1 laminate; median carina sinuate in profile. P2 l/w ca. 2/1, sides parallel, apex blunt, apex raised slightly above mesoventral intercoxal process. Plaques large, anteriorly and posteriorly rounded, parallel, anterior at level of surrounding cuticle, gradually elevating posteriorly such that posterior border is slightly raised above surrounding cuticle, located at sides of median depression. Metaventrite with very short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at slightly arcuate posterior margin ca. 1.5x P2. Protibia moderately wide, slightly arcuate on medial margin, slightly more so on lateral margin. Mesotibia straight; medial margin with 7–8 very short spines (microslide mount), margin not notched between spines. Metatibia slightly arcuate, distal ½ of medial margin slightly emarginate and with large brush of setae. Abdominal apex slightly asymmetrical; last tergite with apicomedian notch.

Females average slightly smaller than males; male metafemur longer and more sinuately shaped than in female; female metatibia simple and slightly shorter than in male.

Remarks. Fairmaire (1898) in the original description notes the differences in the shape of the abdomen of the male and female. It is therefore unquestionable that he had both sexes; however, he does not indicate how many specimens total he had.

The locality given is "Dans l'Ikopa"; Ikopa is the river that flows through Antananarivo. Although the river is quite long, ca. 300 km, the type specimens were most likely collected in or very near the capital. Specimens were collected in the capital as late as 1990, by W. E. Steiner. However, these were not collected in the river, which is now quite polluted.

Trizzino et al. (2012) presented the DNA sequence information of one male specimen ("MNCN AI-547 DNA specimen") with this locality data: Antsaba, Galoko Mountains, hygropetric cascade, elev. 303 m, 13° 39' S, 48° 45' E, 1 xi–29 xii 2004, M. Balke (MD 016).