Ochthebius (Enicocerus) aguilerai, Ribera, Ignacio, Castro, Agustín & Hernando, Carles, 2010

Ribera, Ignacio, Castro, Agustín & Hernando, Carles, 2010, Ochthebius (Enicocerus) aguilerai sp. n. from central Spain, with a molecular phylogeny of the Western Palaearctic species of Enicocerus (Coleoptera, Hydraenidae), Zootaxa 2351, pp. 1-13 : 5-10

Ochthebius (Enicocerus) aguilerai sp.n.

( Figs 1 – 4 , 11 – 13 )

Type locality. Madrid, Puerto de los Cotos, Arroyo de la Laguna Grande de Peñalara, 1600 m, N40º49’59’’ W3º56’09’’ ( Figs 18 – 19 ).

Type material. Holotype male ( MNCN): “ES Madrid, Puerto de los Cotos \ Arryo. Laguna Grande de Peñalara \ 1600 m, N40º49’59’’ W3º56’09’’ \ rd M604 pk 38 20.7.2006 I. Ribera leg.” and holotype label (aedegus extracted and mounted on the same card). Paratypes (31 exx): 1 male and 1 female ( NMW), 1 male ( CVL) and 4 exx ( IBE) labelled as holotype; 2 males ( IBE) and 1 female ( MNCN, DNA voucher MNCN- AI957) “2 ES Madrid Puerto de Cotos 1.7.2006 \ Arroyo de la Laguna Grande de Peñalara \ 1600m N40º49’59’’ W3º56’09’’ \ rd M604 pk 38 IR [I. Ribera] & AC [A. Cieslak] & BR [Bernard Ribera] leg”; 3 males 4 females ( CDTB) “ July 2008, Spain Madrid, Sierra de Guadarrama, Arroyo de la Laguna Grande de Peñalara below Puerto del Coto, D.T. Bilton leg.”; 1 male ( RMNH) “ES: Rascafria, Rio Lozoya \ [WGS84] 30T VL257272 [= 30T 425.7 4527.2] M19W \ 5.vi.2007 \ leg. O.Vorst \ Bergriviertje”; 1 male, 1 female ( COV) “ES: Rascafria, Rio Lozoya \ 30T VL253262 [=30T 425.3 4526.2] M6n \ 1.vi.2007 \ leg. O.Vorst \ Bergbeek”; 1 male ( MNCN, DNA voucher MNCN-AI387) “10 SPAIN Avila, Arenas de S. Pedro \ r. Pelayo, rd. AV924 \ 500m N40º12’06” W5º06’42” \ I.Ribera leg. 15.5.2005 ”; 1 male ( IBE) “2 ES Ávila, Sa. Gredos 280506 \ rv. Pelayo in Arenas de S. Pedro \ rd. AV924, ca. 2Km W Arenas \ 500m N40º12’5,6’’ W5º06’41,5’’ \ I. Ribera & A. Cieslak leg.”; 3 males ( CAC, IBE, MNCN DNA voucher MNCN-AI648) and 1 female ( IBE) “CÁCERES. Jarandilla \ Gta. De Jaranda \ 8.2002 A. Castro leg.”; 5 females ( CDS, CJV, CVL) “ ESPAÑA: Cáceres / Guijo de Sta. Bárbara / 26.06.1991 / leg. J.A. Régil & J.A. Díaz” [specimens recorded as O. legionensis in Garrido-González et al. (1994)].

Aliquots of the DNA extractions are kept in the MNCN ( DNA and tissue collection) and the IBE.

Additional material. 1 male ( CVL): “Madrid (Norte), 1978 \ E. Roy leg.” (not designated as paratype due to the imprecise location).

Description. Habitus as in Figs 1 – 2 . Body length 1.9 – 2.1 mm. Colour black, with strong greenish metallic reflections. Body appendages yellowish brown; apical half of antennae, palpi, knees and tarsi darker. Upper surface very sparsely covered with short whitish adpressed pubescence. Anterior margin of the labrum emarginated; anterior lobes transverse, exterior angle frequently with a spine. Labrum and clypeus with large punctures; surface with a distinct microreticulation. Frons more densely punctate, with a shagreened appearance. Pronotum of female and some males not very convex, roughly trapezoidal, admedian fovea and sulcus well impressed, median sulcus reaching anterior and posterior margins; pronotal punctures strongly impressed, sparse, space between punctures usually smooth and glabrous. In some males pronotum strongly convex, with admedian foveas more elongated, surface with less impressed punctation ( Fig. 1 ). Elytra oval, strongly convex, with ten strongly impressed regular striae; second interval flat and smooth, specially in male with convex pronotum; third interval strongly raised near the basis. Suture very depressed anterior to and strongly raised posterior to middle of elytra, so that in lateral view each elytron show a distinct median depression. Aedeagus as in Figs (3, 4), long and slender. Main piece, in ventral view, distinctly narrowed behind insertion of parameres, in lateral view, apex narrow and tapered; parameres short, adjoining median lobe. Female tergite X ( Figs 11 – 13 ) with a small medial protuberance visible in lateral and caudal view.

Distribution. Mountains of the Spanish Sistema Central, from north-east of the province of Cáceres to Sierra de Gredos and Guadarrama ( Fig. 17 ). The record of O. legionensis in Garrido-González et al. (1994) from NE Cáceres corresponds to this species (see Type Material). Although there are no genetic data available, according to the external morphology the populations of the north Iberian System (Burgos and Soria, Valladares et al. 2000) and Málaga ( Jäch et al. 1999) ( Fig. 17 ) would belong to O. exsculptus (J. Garrido, L.F. Valladares and M.A. Jäch, personal communication 2009). The records from Albarracín (Teruel) in d’Orchymont (1941) have been considered as O. exsculptus in Fig. 17 , although we have not examined the specimens.

Etymology. Named after our friend and water-beetler Pedro Aguilera, who died in an accident in February 2009.

Ecology. The new species is found in fast flowing, clean mountain streams in granitic substratum, usually on the surface of large semi-submerged rocks ( Figs 18 – 19 ). In the type locality (the one in which the species seems to be more abundant) it was collected in the company of an abundant and diverse fauna of Hydraenidae ( H. brachymera d’Orchymont , H. corinna d’Orchymont , H. exasperata d’Orchymont , H. iberica d’Orchymont , H. hispanica Ganglbauer , Hydraena sharpi Rey , Limnebius truncatellus Thunberg , Ochthebius heydeni Kuwert ), all of them Iberian endemics except L. truncatellus ( Jäch 2004) .

Comparative notes. Ochthebius aguilerai sp.n. is very similar to O. legionensis in its external morphology, but females of both species can easily distinguished by the shape of the last terguite, specially when observed in lateral and caudal view ( Figs 11 – 16 ). We have not found any other constant external character to separate these two species, although O. aguilerai sp.n. tends to be slightly smaller and with a more strongly puncturated pronotum. The aedeagus of O. legionensis ( Figs 5 – 6 ) differs from that of O. aguilerai n.sp. ( Figs 3 – 4 ) by its more robust main piece, ventrally less narrowed behind insertions of parameres, and with a broadly truncate apex. The apical lobe of O. aguilerai n.sp. is more slender and with a less sharp bend that that of O. legionensis ( Figs 3 – 6 ).

Ochthebius aguilerai n.sp. and O. legionensis can be easily distinguished from the other Iberian species of the O. exsculptus group by the presence of an elytral depression. The apex of the median lobe of the aedeagus of O. aguilerai n.sp. is less truncated in ventral view than that of O. exsculptus , and less pointed in lateral view ( Figs 3 – 4, 7 – 10 ). The apical lobe of both species are very similar.

The size of the species of the O. exsculptus group is rather variable, and there is a significant correlation between body and aedeagus size (for Iberian specimens of the three species r2 = 0.74, p <0.01, n = 13). Specimens of O. aguilerai sp.n. and of the southern clade of O. exsculptus (see below) seem to have proportionally smaller aedeagus, but in any case, and due to the large overlap between species, these would be statistichal trends without diagnostic value.

Ochthebius aguilerai sp.n. seems to be in some characters closer to the Central European O. halbherri . Both species share an aedeagus with a dorsally constricted main piece, ending in a narrow apex, although both species can be easily distinguished by the shape of the apex of the median lobe (see Jäch 1992: Fig. 8 ). The female tergite X is also similar in both species (see Jäch 1992: Fig. 4 ), although the apical protuberance is distinctly less developed in O. aguilerai sp.n.

Figures

FIGURE 17. Distribution map of the Iberian species of the Ochthebius (Enicocerus) exsculptus group. With black circles, localities from which at least one specimen has been sequenced.

FIGURES 1 – 2. Habitus of Ochthebius aguilerai sp. n., 1) male (paratype, NMW); 2) female (paratype, NMW).

FIGURES 3 – 10. Aedeagus of O. aguilerai sp. n. 3) lateral and 4) ventral view (Paratype from type locality); O. legionensis 5) lateral and 6) ventral view (voucher specimen MNCN-AI 906); O. exsculptus (northern clade, voucher specimen MNCN-AI 1069) 7) lateral and 8) ventral view; and O. exsculptus (southern clade, Granada, Río Genil) 9) lateral and 10) ventral view. See Table 1 for details of the localities. Scale bar, 0.25 mm.

FIGURES 11 – 16. Last abdominal tergites of O. aguilerai sp. n. 11) ventral, 12) lateral and 13) caudal views (paratype from type locality) and O. legionensis 14) ventral, 15) lateral and 16) caudal views (León, Rioscuro, 30.6. 1985 L. F. Valladares leg.). Scale bar, 0.25 mm.

FIGURES 18 – 19. Type locality of O. aguilerai sp. n. (Arroyo de la Laguna Grande de Peñalara), 18) top, 2 June 2007, with D. T. Bilton and F. Bameul; 19) bottom, 20 July 2006, detail of the microhabitat (fotos, IR).