Hydroporus queneyi, Manuel & Ferreira, 2024

Manuel, Michaël & Ferreira, Jules, 2024, Hydroporus queneyi sp. n. from southern France, a new semi-subterranean diving beetle of the Hydroporus normandi-complex (Coleoptera, Dytiscidae, Hydroporini), Zootaxa 5403 (2), pp. 239-255 : 242-249

Hydroporus queneyi sp. n.

Figures 1 , 2 , 6–9 , 18–22, 26.

Type locality. Southern France, Occitanie region , Hérault department, Les Matelles, ca. 10 km NNW of Montpellier, ruisseau de la Déridière (name of the stream), GPS coordinates 43°44’N 3°48’E, altitude 110 m.

Type material. Holotype (♂): “ France, dpt. 34, Les Matelles , / ca. 10 km NNW Montpellier / 21.V.2018. 43°43'48''N / 3°48'03''E. Alt. 110 m. ” // “In hole dug into calcareous / gravel next to puddle / in brooklet bed, clear water. / Manuel & Queney leg. [white, printed]” // “Holotype, Hydroporus queneyi sp. n., Manuel & Ferreira det. 2023 [red, printed]” ( MNHN) . Paratypes (in total 13♂♂, 16♀♀) ( CHF, CMM, CPQ, MNHN, NMPC): 6♂♂, 10♀♀: same data as holotype; including five DNA vouchers ( Table 1 ). 7♂♂, 6♀♀: “ France, dpt. 34, Les Matelles , / ca. 10 km NNW Montpellier / 18.V.2021. 43°43'50''N / 3°48'14''E. Alt. 100 m ” // “Little spring with stones, / abundant vegetal debris and / orange deposit, bottom of / embankment, in bed of / ruisseau de la Déridière./ Manuel & Ferreira leg.”, including three DNA vouchers ( Table 1 ). All paratypes with the respective printed red label.

Description of holotype. Habitus ( Fig. 1 ) elongate and subparallel, with large head; posteriorly with sides converging rather shortly before rounded apex. Outline continuous between pronotum and elytron. Maximum width slightly before midlength of body. Pronotum broad; at posterior angles slightly wider than elytra at shoulders; ratio between maximum pronotum width and maximum body width about 0.95. Dorsal surface weakly convex. Dorsal surface entirely reticulated and strongly shiny, with pubescence very short and sparse.

Head dark rufous, on clypeus and medial region of vertex paler; lateral regions of vertex (behind eyes) black ( Fig. 1 ). Eyes small ( Fig. 1 ); ratio between interocular distance and maximum pronotum width about 0.5; outer eye outline continuous with clypeus outline. Clypeo-frontal depressions subcircular and shallow. Entire dorsal surface with strongly impressed reticulation (meshes small, round to vaguely polygonal); with rather fine and dense punctures, their diameter quite homogeneous (between one and two meshes of the reticulation); in clypeo-frontal depressions and along inner eye margin punctures coarser and denser, with short setae.

Pronotum in discal region dark brown, anteriorly, posteriorly and laterally gradually paler; lateral bead rufo-testaceous ( Fig. 1 ). Maximum width at posterior angles. Lateral margins more or less evenly rounded, at anterior angles more curved inwards. Posterior angle right-angled. Lateral bead thick and well-defined, continuous from posterior to anterior angle. Entire surface with strongly impressed reticulation; meshes of same size as on head, round to vaguely polygonal. On disk with fine and sparse punctures, their diameter heterogeneous (from less than one to slightly more than two meshes of reticulation); in central disk region punctures coarser and denser. Along anterior margin with irregular row of dense coarse punctures; along posterior and lateral margins with sparse coarse punctures. Laterally before posterior margin with dense group of coarse punctures in distinct, slightly elongated transverse-oblique depression. Punctures each bearing very short seta; along anterior margin and in postero-lateral depressions with longer setae.

Elytra in between discal puncture rows dark brown; along base, brown colour extending laterally beyond discal puncture rows; along suture with diffusely delimited rufous area; laterally and posteriorly gradually becoming rufo-testaceous ( Fig. 1 ). Lateral margins anteriorly subparallel until about 55% of elytral length, then progressively attenuated to rounded apex ( Fig. 1 ). In lateral view elytral margin distinctly ascending towards humeral angles; epipleuron not visible until humeral angle. Dorsal surface flat in anterior third in between discal puncture rows; in lateral view dorsal outline of elytra continuous with that of pronotum and almost perfectly horizontal until about elytral midlength. Entire surface with rather strongly impressed reticulation; meshes slightly larger than on pronotum, distinctly polygonal. On elytral disk punctures fine and moderately dense ( Fig. 1 ); puncture diameter heterogeneous, between one and two meshes of reticulation; mean distance between punctures between one and slightly more than two puncture diameters. Discal and lateral puncture rows distinct. Most elytral punctures bearing very short seta; along discal puncture row with longer setae.

Ventral surface. Head rufo-testaceous, including gula; genae black.Ventral surface of prothorax and mesothorax, and elytral epipleura, rufous; antero-medial region of prosternum not darker than lateral regions; prosternal process rufo-testaceous. Ventral surface of metathorax and metacoxa black; metacoxal processes rufo-testaceous.Abdominal ventrites dark brown. Surface of genae with rather weakly impressed reticulation, without punctures; surface of gula smooth and very shiny, with coarse rather sparse punctures. Antero-medial region of prosternum (before procoxae) with surface micro-granulose, with large and dense shallow punctures. Prosternal column (between procoxae) without distinct protuberance at level of anterior third of procoxae; before anterior third of procoxae, file with about five weakly impressed transverse ridges, with surface smooth and with strong declivity. Prosternal process lanceolate; in cross section strongly and evenly convex; apex bluntly pointed; with very narrow lateral bead; surface smooth; laterally with sparse and rather short setae. Elytral epipleura along inner margin with thick bead; surface with weakly impressed reticulation, with sparse shallow punctures, along inner marginal bead punctures larger. Surface of metaventrite smooth, medially with fine and rather sparse punctures, laterally with very coarse, large and dense punctures. Surface of metepisternum with obsolete reticulation, impunctate. Surface of metacoxal plate on lateral two thirds with very weakly impressed reticulation, on inner third partly with obsolete reticulation and partly smooth; on lateral third with fine and sparse punctures, on inner two thirds with much coarser and denser punctures. Metacoxal lines strongly impressed, weakly divergent, ending shortly behind posterior margin of metaventrite ( Fig. 2 ); in between metacoxal lines surface smooth, with few fine punctures. Metacoxal processes conjointly with posterior margin medially produced, laterally on both sides slightly concavely sinuate ( Fig. 2 ). Surface of ventrites I–III with weakly impressed reticulation, on ventrite II medially smooth; surface of ventrites IV–VI with strongly impressed reticulation. Surface of ventrites I–II with rather coarse and moderately dense punctures, on ventrite II medially with fine and sparse punctures; surface of ventrites III–VI with fine and sparse punctures. Whole ventral surface with short and sparse pubescence; in antero-median region of prosternum, and along midline shortly before posterior margin of metacoxal processes ( Fig. 2 ), with small rather long and dense golden setae.

Appendages. Antennae with antennomeres I–IV testaceous, antennomeres V–XI slightly infuscate in distal twothirds; antennomeres V–X twice as long as broad ( Fig. 1 ). Palps entirely testaceous. Legs rufo-testaceous. Ventral surface of pro- and mesotarsomeres I–III with dense short trumpet-like (distally enlarged) setae; ventral surface of pro- and mesotarsomere I additionally with several centrally located sucker cups. Protarsal claws unmodified, regularly arcuate, narrow and equal.

Aedeagus. Median lobe in lateral view as in Fig. 6 (holotype) and Fig. 8 (paratype); in ventral view as in Fig. 7 (holotype) and Fig. 9 (paratype); parameres as in Fig. 18 (holotype).

Posterior wings. Extracted from three paratypes (two males and one female); in each case with short but well-defined posterior cubital vein ( Fig. 26 ).

Females. Pro- and mesotarsomere I slightly narrower than in males, their ventral surfaces without sucker cups. No other conspicuous external differences to males (except one matt female, see Variation). Gonocoxosternum as in Fig. 19 ; gonocoxa as in Figs 20–22 .

Measurements. Holotype: TL = 3.4 mm, TL without head = 3.0 mm, MW = 1.55 mm, ratio TL/MW = 2.21. Paratypes: TL = 3.25–3.7 mm (3.48 ± 0.13), TL without head = 2.85–3.3 mm (3.06 ± 0.10), MW = 1.50–1.65 mm (1.58 ± 0.05), TL/MW = 2.12–2.31 (2.21 ± 0.05).

Variation. Very little variation in habitus; a minority of paratypes with pronotum at posterior angles not broader than elytra at shoulders. Head colour from pale rufous to dark brown; pronotum and elytra in some specimens paler and in others darker than in holotype. Antennomeres V–XI from very slightly (albeit distinctly) to rather strongly infuscate. Specimens with antennomeres V–XI darker also with dorsal surface and legs darker. One female paratype with elytral surface distinctly matt. Shape of median lobe of aedeagus in ventral view variable, in apical third below apical region with lateral outlines parallel as in holotype ( Fig. 7 ) or more or less progressively narrowing from base to apical region (as in Fig. 9 ).

Differential diagnosis. Within the H. normandi -complex, the new species differs from all previously described species by the antennomeres V–XI slightly but distinctly darker than antennomeres I–IV (in all other species, antennae entirely testaceous, Manuel 2013, Vorst & Fery 2014). It can be furthermore recognised by the following diagnostic combination of characters: habitus strongly elongated and parallel (lateral outline of elytra parallel until about half of elytral length); maximum pronotum width at posterior angles; pronotum at posterior angles broader than elytra at shoulders (in most specimens); elytral punctures moderately fine; reticulation on pronotum and elytra strongly impressed; pubescence weak; metacoxal lines weakly divergent; posterior cubital vein (posterior wing) short but distinct; ventral outline of median lobe of aedeagus slightly sinuated in lateral view below apex; proximal extremity of gonocoxae more or less dilated. Comparisons with H. galloprovincialis , H. normandi , H. lluci and H. productus for these characters are presented in Table 2 , with reference to illustrations when available (for habitus characters of species other than H. queneyi sp. n., see illustrations in Fery 1999 and Manuel 2013). Finally, H. queneyi sp. n. differs from H. emergens by the more strongly parallel-sided habitus and by different shapes of the median lobe of aedeagus and parameres (illustrations in Vorst & Fery 2014).

In the identification key to western Mediterranean species and subspecies of the H. normandi -complex published by Manuel (2013), H. queneyi falls in couplet 6, which should be modified as follows:

6. Antennomeres V–XI slightly darker than antennomeres I–IV; species from southern France (Occitanie).... H. queneyi sp. n.

- All antennomeres testaceous............................................................................ 7

7. Body distinctly more elongate and parallel; head large with inter-ocular distance at least equalling half of pronotum width at hind angles; clypeus broadly truncate; pronotum at hind angles generally wider than body at shoulders; pronotal sides subparallel in posterior half; species from south-east France (Provence)........................... H. galloprovincialis

- Body subparallel but less elongate; head narrower, inter-ocular distance smaller than half of pronotum width at hind angles; clypeus more narrowly truncate; pronotum at hind angles not wider than body at shoulder; pronotum sides converging from hind angles; species from Balearic Islands ............................................................. H. lluci

Habitat. Specimens were found on two occasions, in May 2018 and May 2021, at two different places about 250 m apart from each other along the same small stream. The first site (May 2018; Figs 29–31 ) was a small pool (about 2 m x 1 m; maximum depth about 10 cm) with clear water and a bottom of calcareous gravel and small stones, with no vegetation. Water was very slowly seeping from a sloppy surface of concrete, located below a pipe ( Fig. 30 ) draining water from the underside of a nearby dirty road. The place was semi-shaded as the stream was rather strongly embanked and was lined with grass and shrubs, with a dominant vegetation of Pistacia lentiscus , Phillyrea angustifolia , Celtis australis , Rhamnus alaternus , Juniperus oxycedrus , Rosa sp. and Rubus sp. At this place, most specimens of H. queneyi sp. n. were not obtained by sweeping the net directly into the pool, but by digging holes into the gravel around the pool, letting water seep into these holes then filtering ( Fig. 30 ). Other Dytiscidae species collected at this site were Agabus brunneus (Fabricius, 1798) and Hydroporus obsoletus Aubé, 1838 (this species with a localised distribution in southern France, Bameul & Queney 2014; first record for the French department of Hérault).

In May 2021, the water level was much higher than three years before. Our attempts to find specimens at the same place as in May 2018 were unsuccessful. However, about 250 m downstream, we could sample the species in a small marginal spring located in a depression along the stream bank (about one meter higher than water level in the stream bed) ( Figs 32–33 ). The new species was very strictly localised to a single puddle ( Fig. 33 ) which was the head of this micro-spring, whereas several other similarly looking puddles located immediately downstream (such as the one shown in Fig. 32 ) delivered no specimen. This puddle was about 50 cm in diameter and less than 10 cm in depth. Water was very slowly flowing from the calcareous substratum. The puddle was heavily loaded with decaying organic matter and orange deposit from iron bacteria ( Fig. 33 ), with a few calcareous stones on the bottom. There were sparse tufts of Scirpoides holoschoenus subsp. romanus ( Cyperaceae ) ( Fig. 33 ), and the site was fully shaded under dense trees and shrubs, with a dominant vegetation of Quercus alba , Fraxinus angustifolia , Phillyrea latifolia , P. media , Osyris alba and abundant Rubus sp. Hydroporus queneyi sp. n. was the only dytiscid species collected in this puddle; a few meters downstream, in a narrow channel fed by the micro-spring, we found two specimens of Agabus brunneus .

Distribution. So far known only from the type locality, Les Matelles, north of Montpellier in southern France, Hérault department ( Fig. 34 ).

Derivatio nominis. This species is dedicated to Pierre Queney, in recognition of his invaluable contribution to the knowledge of French water beetles. The specific epithet is a name in the genitive case (singular).

Figures

FIGURE 1. Habitus in dorsal view of Hydroporus queneyi sp. n. (holotype). Scale bar: 1 mm.

FIGURE 34. Distribution map of the western Mediterranean species of the H. normandi-complex (i.e., excluding H. emergens). Data from Fery (1999), Fery & Fresneda (2007), Manuel (2013), Millán et al. (2014), Elder (2015) and this study. Empty violet symbol: specimen of H. galloprovincialis collected in 1926 by L. Puel among detritus on the beach of Saintes-Maries-de-la- Mer (probably flowed out from an unknown inland locality). Empty blue symbol: uncertain data for H. normandi in the French Pyrénées-Orientales (see Discussion). Surface currents according to https://www.culture-maritime.com/fr/page-mme3_cours. xhtml.

FIGURES 2–5. Metacoxal processes of: (2) Hydroporus queneyi sp. n. (male paratype); (3) H. galloprovincialis (male specimen from Jouques, France); (4) H. normandi normandi (male specimen from Los Pozuelos de Calatrava, Spain); (5) H. lluci (male specimen from Majorca, Balearic Islands). Scale bar: 0.2 mm.

FIGURES 6–17. Median lobe in lateral (6, 8, 10, 12, 14, 16) and ventral (7, 9, 11, 13, 15, 17) view of: (6–9) Hydroporus queneyi sp. n. (6, 7: holotype; 8, 9: paratype); (10, 11) H. galloprovincialis (holotype); (12, 13) H. normandi normandi (specimen from Los Pozuelos de Calatrava, Spain); (14–17) H. lluci (14, 15: paratype; 16, 17: specimen from Majorca, Balearic Islands). Scale bar: 0.1 mm.

FIGURES 18–25. Left paramere (18) (holotype), gonocoxosternum (19), and gonocoxa in inner (20) and dorsal (21–25) view of (18–22) Hydroporus queneyi sp. n. (18: holotype; 19–22: paratypes); (23) H. galloprovincialis (paratype); (24) H. normandi normandi (specimen from Aljezur, Portugal); (25) H.lluci (specimen from Majorca, Balearic Islands).Arrow:proximal extremity of gonocoxa. Scale bar: 0.1 mm.

FIGURES 26–28. Detailed view of the posterior wing in the region of the posterior cubital vein (for the venation pattern on the whole posterior wing, see Figures 53–54 in Manuel 2013) of: (26) Hydroporus queneyi sp. n. (male paratype); (27) H. galloprovincialis (paratype); (28) H. normandi normandi (specimen from Los Pozuelos de Calatrava, Spain).AA3: third branch of the anal anterior vein; Cu: cubital vein; CuA: anterior cubital vein; CuP: posterior cubital vein. Scale bar: 0.05 mm.

FIGURES 29–33. Habitat of Hydroporus queneyi sp. n. (Les Matelles, Hérault, France). (29) General view of the locus typicus (21.V.2018); (30) Hole dug into the gravel on the stream bed, below the extremity of a pipe from which water was slowly seeping; (31) Detailed view of the pool; (32) General view of the second sampling site (18.V.2021), showing the vegetation context around a large puddle just downstream from the micro-spring where the new species was sampled; (33) Detail of the puddle in which specimens of H. queneyi sp. n. were concentrated.