Hydraena diazi, Trizzino, Marco, Jäch, Manfred A., Audisio, Paolo & Ribera, Ignacio, 2011

Trizzino, Marco, Jäch, Manfred A., Audisio, Paolo & Ribera, Ignacio, 2011, Molecular and morphological analyses confirm two new species of the Hydraena emarginata – saga clade (Coleoptera, Hydraenidae) from Spain and France, Zootaxa 2760, pp. 29-38 : 30-32

Hydraena diazi n. sp. Trizzino, Jäch & Ribera

( Figs 1 –4)

Type locality. Spain, Barcelona province, Montseny, La Costa, Sot de Ritronyes, 620 m, N41º45’23.5” E2º24’49.8”.

Type material. Holotype male ( MNCN): “ES Barcelona, Montseny 10.9.2006 / La Costa de M.: Sot de Ritronyes / 620m N41º45’23.5” E 2º24’49.8” /Ribera, Hernando & Aguilera leg.”. Paratypes (58 specimens: CSR, IBE, MNCN, NMW): 6 males and 10 females same locality and data as holotype; one of the males used for DNA extraction and sequencing, voucher number MNCN-AI479. 2 males and 4 females Spain, Barcelona province, Montseny, Santa Fe del Montseny, road Turo del Home to Sot de Bernadal, 1134 m a.s.l., N41º45’45.2” E2º26” 55.0”, 23.7.2005, Ribera leg. 2 males Spain, Guipuzkoa province, Oiartzun, 240 m a.s.l., N43°16’10.2” W01°48’20.5”, 16.7.2006, Ribera & Cieslak leg.; one used for DNA extraction and sequencing, voucher number MNCN-AI1011. 1 male and 1 female Spain, Girona province, Meranges, Fontanera, torrent de la Mata de l’Os, Ribera & Aguilera leg. 10.6.1995. 1 male Spain, Barcelona, Bagà, Riera de Gréixer, N38°12’52.4” E02°59’18.5”, 1000 m, 22.6.1994, Fresneda leg. 5 males and 8 females Spain, Barcelona, Mosqueroles, Riera Ciuret, N41°43’50.5” E02°26’04.2”, 440 m, 20.3.1989, Fresneda leg. 1 male and 4 females Spain, Barcelona, Mosqueroles, Riera Ciuret, N37°46’20.5” E03°21’34.8”, 440 m, 23.3.1989, Fresneda leg. 1 male Spain, Vizcaya, Villaro, Río Arratia, N38°55’ 45.9 E03°47’35.9”, 140 m, 5.6.1985, Rico leg. 1 male and 6 females Spain, Lleida, Salardú-Naut Aran, Montgarri, N38°35’49.2” E02°27’49.7”, 1650 m, 15.10.1985, Fresneda leg. 1 female Spain, Lleida, Es Bordes, Artiga de Lin, N42°43’04.3” E0°43’26.3”, 1012 m, 11.5.1986, Fresneda leg. 2 males and 2 females Spain, Lleida, Vielha-Mig Aran, Boca nord túnel de Vielha, N38°31’26.2” E02°20’41.7”, 1510 m, 2.4.1989, Fresneda leg.

Additional material. 1 male France, Eastern Pyrenees, Les Angles. 1 male and 1 female France, Eastern Pyrenees, Larrau. 1 male France, Eastern Pyrenees, Suchon. 1 male France, Eastern Pyrenees, Gabas. 2 males Spain, Catalonia, Lleida.

Description. 2.2–2.4 mm long. Head, pronotum and elytra dark brown to black, distal third of elytra in some specimens dark reddish brown to paler reddish brown. Palpi and legs paler reddish brown.

Head: labrum with V–shaped notch anteriorly (but not as deep as in e.g. Hydraena larissae ). Fronto–clypeal suture slightly arcuate, not strongly impressed. Middle of frons moderately densely punctate, lateral portion of frons very densely punctate, as in related species. Occipital ridge well developed. Eyes moderately large, maxillary palpi very long, about twice as long as distance between eyes.

Pronotum wider than long, moderately cordiform, anterior margin emarginate, anterior angles more or less rounded. Lateral margin slightly denticulate. Disc slightly more convex than in Hydraena larissae , rather densely punctate near anterior and posterior margins, along midline and around posterior foveae. Foveae hardly impressed.

Elytra elongate, parallel–sided, rather strongly declivous laterally. Nine rows of punctures between suture and shoulder. Strial punctures moderately large, slightly more deeply impressed than in H. saga and H. larissae . Explanate margin of elytra moderately wide, as in all members of the H. emarginata – saga complex.

Mentum and submentum microreticulate. Posterior genal ridge not particularly prominent, mostly glabrous. Prosternum with indistinct median keel. Angles between mesoventral disc and mesoventral process small as in e.g. H. larissae and H. saga . Metaventral plaques well developed, divergent posteriorly. Glabrous areas behind metacoxal sockets not very pronounced; abdominal ventrites III–VI more or less entirely covered with hydrofuge pubescence, abdominal ventrites VII and VIII largely glabrous, as in related species.

Aedeagus ( Fig. 1 ): Length of main piece 572 μm (holotype), with four setae, three on left side and one very reduced (typical of members of the H. emarginata – saga group) on right side. Apex distinctly more rounded than in H. saga and H. alpicola (Figs 9, 10); a peculiar and clearly visible small V–shaped incision on pre–apical dorsal side of main piece. Distal half of main piece in right side view markedly more curved and wider (about 1.3 times) than in H. saga . Pre–basal tooth not very prominent, phallobase symmetrical in ventral view. Distal lobe as in H. saga and H. alpicola , seemingly without variability in size.

Gonocoxite and female tergite X as in Figs 2–3.

Secondary sexual characters: male elytral apices conjointly rounded, with very small sutural notch. Female elytral apices slightly conjointly rounded (Fig. 4), with a more or less large sutural notch. Female ventrites V and VI with fringe of long setae. Male ventrite VI enlarged. Male mesotibia with a row of ca. eight minute denticles along mesial face of posterior half. Male metatibia with fringe of long setae along mesial face of posterior half. Male tergite X as in H. saga and related species.

Differential diagnosis. H. diazi is clearly related to H. saga , H. larissae , H. emarginata , H. alpicola , and especially to the second new species described in this paper (see below; see also Fig. 12 ). The aedeagus of H. diazi ( Fig. 1 ) could be easily distinguished from the other related species by the markedly curved and wide apical half of the main piece and by the peculiar distal apex of the main piece. The aedeagus of H. emarginata ( Fig. 11) can be distinguished also by its distinctly larger size (PL: 610–665 μm), and by the distinctly larger distal lobe.

Distribution. H. diazi has a typical Pyrenean distribution, occurring in the southern (Spanish) and in the northern (French) side, and extending to some mountain massifs in Catalonia ( Fig. 13 ). All Pyrenean specimens previously attributed to H. saga almost certainly belong to H. diazi .

Etymology. We are pleased to dedicate this species to our dear friend and colleague Juan Angel Díaz (University of Santiago de Compostela, Spain).

Figures

FIGURE 1. Aedeagus in right side view of Hydraena diazi (Spain, Guipuzkoa prov., Oiartzun). Scale bar = 0.2 mm. FIGURE 2. Female gonocoxite of Hydraena diazi (Spain, Barcelona prov., Santa Fe del Montseny). Scale bar = 0.2 mm. FIGURE 3. Female tergite X of Hydraena diazi (Spain, Barcelona prov., Santa Fe del Montseny). Scale bar = 0.2 mm. FIGURE 4. Female elytral apices (not scaled) of Hydraena diazi (Spain, Barcelona prov., Santa Fe del Montseny). FIGURE 5. Aedeagus in right side view of Hydraena fosterorum (Spain, Burgos prov., Fresneda de la Sierra). Scale bar = 0.2 mm.

FIGURE 12. Phylogram of the species of the H. gracilis lineage obtained with RAxML. Numbers at nodes represent Bootstrap support values in RAxML / Bayesian posterior probabilities (only if> 70 % and 0.7 respectively).

FIGURE 13. Geographic distribution of members of the H. emarginata – saga clade. Sequenced populations of the two new species are marked with a black dot within the symbol.