Hydroporus neclae, Erman, Ömer Köksal & Fery, Hans, 2006

Erman, Ömer Köksal & Fery, Hans, 2006, Hydroporus neclae sp. n. from north-eastern Turkey, a new member of the memnonius - group of Hydroporus Clairville (Coleoptera: Dytiscidae), Zootaxa 1355, pp. 39-47 : 41-45

Hydroporus neclae sp.n.

( Figs. 1 , 4, 7, 10–12 )

Type locality. Turkey: Erzurum Province, Bingöl Mountains, SSE Hamzalar, 39.23.09N 41.22.07E, ca. 2150 m.

Type material: Holotype: Male: 19.7.2004 Turkey, Erzurum, Bingöl Mts., ca. 30 km SW Tekman, SSE Hamzalar, ca. 2150 m, little ponds, Ö. Köksal Erman leg., 39.23.09N 41.22.07E [printed], “ Holotype, Hydroporus neclae sp.n., Ö. Köksal Erman & H. Fery det. 2006 [red, printed] ( NMW). Paratype: 1 female: same label data as the holotype, and with a red paratype label ( CKE).

Description. Habitus and size. Body narrowly elongate ( Fig. 1 ), elytra almost parallel in anterior two thirds, widest shortly before middle; in dorsal view without discontinuity in outline between pronotum and elytra. The measurements give the following values: Holotype (male): TL: 3.6 mm, TL-H: 3.3 mm, MW: 1.75 mm, WP: 1.55 mm; TL-H/WP: 2.12. Paratype (female): TL: 3.5 mm, TL-H: 3.2 mm, MW: 1.65 mm, WP: 1.5 mm; TL-H/ WP: 2.13.

Colour. Both specimens studied are slightly immature and, thus, the upper and ventral surface brown to dark brown. We assume, however, that mature specimens, as other similar species of the memnonius -group and in particular H. longicornis , are blackish brown or even black, with some parts being lighter brownish. Despite this immaturity, it can be recognised that the head has the anterior margin of clypeus lighter, as well as a rather broad transverse stripe on frons; the antennal articles are lighter brownish and darkened apically beginning with the fifth; most probably, the gula is lighter than the genae, and the sides of pronotum, at least the rim lighter than its disc; finally, the legs seem to be lighter brownish than most other parts of the venter.

General surface sculpture. Entire surface covered by fine reticulation of small, more or less round meshes, however, in contrast to H. longicornis , and especially to H. melanarius , not appearing dull at all, but shiny throughout, even on apex of elytra.

Head. Punctation simple and sparse, denser and coarser in two clypeal grooves between anterior margin of eyes; punctation on frons and vertex absent. Second article of antennae almost as long as third and fourth together; third and fifth articles of same length, fourth one shorter than these.

Pronotum. Punctation near margins coarse and rather dense; inside hind angles with an impression, however, not nearly as deep as in H. obsoletus ; here coarse punctures still denser and longitudinally prolonged in part. Disc of pronotum with only a few fine punctures, but a distinct scratch in its centre. Lateral margins in posterior half almost straight and converging anteriorly, stronger rounded anteriorly; lateral beading rather broad, more or less equal to half of diameter of antennal articles.

Elytra. Punctation simple and almost evenly distributed, punctures rather coarse, only finer beside suture and on apex; on disc distance between punctures ca. 1.5 that of their diameter; puncture lines almost imperceptible. Beading of margins in lateral view distinct, epipleuron not visible to humeral angle; lateral margin weakly ascending to humeral angles. Epipleura with a few coarse punctures. Setae on elytra present, but extremely fine and almost imperceptible.

Ventral surface. Sides of metasternum, metacoxae, and abdominal sternites with fine microreticulation, almost imperceptible in middle of third sternite, strongly impressed on last sternite, however, entire surface shiny. Large parts of venter provided with fine sparse yellowish setae, however these are rather indistinct. Prosternal process with a transverse ridge between procoxae, anteriorly not prolonged as a convexity, but flat and here provided with some very weak transverse grooves; shape of blade (behind procoxae) lanceolate, longitudinally carinate, sides narrowly flattened, here with a few coarse punctures and short setae; apex of process shortly rounded. Metasternum, metacoxae, and first two abdominal sternites with coarse punctures, however, centre of metasternum and areas right and left of it without punctures. Third to sixth sternite with punctures sparser and smaller. Metacoxal lines divergent anteriorly, ending short before posterior margin of metasternum; intralinear space with a few coarse and in part longitudinally prolonged punctures, in posterior half with distinct suberect yellowish setae. Posterior margin of each metasternal process almost straight, but both forming an obtuse angle ( Fig. 12 ), thus, similar to those of H. melanarius (cf. Fig. 194 in Nilsson & Holmen 1995). Protibia provided with one line of coarse punctures.

Male. Median lobe ( Fig. 4 ) in ventral view almost evenly tapering to apex in apical half, not strongly narrowed before tip and with long process as in H. longicornis (compare Fig. 5 ) (the base of the median lobe is somewhat incomplete and deformed, probably due to the immaturity); paramere as in Fig. 7 . Compare also the median lobe of H. melanarius ( Fig. 6 ) and its paramere ( Fig. 9 ) and that of H. longicornis ( Fig. 8 ). First three protar-someres—if at all—indistinctly broadened, protarsal claws more curved near base, otherwise straighter than in female.

Female. Gonocoxosternum as in Fig. 11 ; gonocoxae ( Fig. 10 ) without any angularity on inner side (cf. Figs. 78–80 in Fery 1999). Reticulation on head and pronotum slightly more strongly impressed than in males, nevertheless, surface not appearing dull. Protarsal claws evenly curved. Transverse grooves on base of prosternal process more distinct than in male holotype, this, however, possibly due to individual variation.

Distribution. Turkey; known only from the type locality.

Etymology. Named for Necla, the first name of the senior author's mother.

Faunistics. Hydroporus neclae was found in an assemblage of about 10 ponds on a mountainous plain at an altitude of ca. 2150 m. These ponds have diameters of 5–30 m, and a depth of 1 m or somewhat more. The smaller ponds have well developed vegetation, the bigger ones less so. Other Dytiscidae found in these ponds are: Agabus bipustulatus (Linnaeus) , A. caraboides Sharp , A. congener (Thunberg) , A. glacialis Hochhuth , A. labiatus (Brahm) , A. nebulosus (Forster) , Platambus lunulatus (Fischer von Waldheim), Hydroporus erzurumensis (recorded with doubt since both specimens collected are very immature), H. kozlovskii , H. marginatus (Duftschmid) , H. nigellus , H. palustris (Linnaeus) , H. pubescens (Gyllenhal) , H. thracicus , H. transgrediens Gschwendtner , Hygrotus lernaeus (Schaum) , H. marklini (Gyllenhal) , Scarodytes halensis (Fabricius) , and Stictotarsus griseostriatus (De Geer) .

Discussion. Hydroporus neclae is most similar to H. longicornis and H. melanarius Sturm. It can be separated from the latter by the narrower habitus (cf. Figs. 1, 3 ), shape of the median lobe (cf. Figs. 4, 6 ), and the surface of the cuticle which is reticulate in both species, but dull in both sexes of H. melanarius , and shiny in H. neclae . Both the holotype and paratype have the TL-H more than twice as long as the WP, a feature which was used by Nilsson & Holmen (1995: 44) to separate H. longicornis from H. melanarius , and, thus, H. neclae 's body shape clearly fits more that of the narrowly elongate H. longicornis than that of the broader H. melanarius . The shape of the hind margins of the metacoxal processes is more or less the same in both species ( Fig. 12 ). On a first glance, H. neclae could also be taken for a member of the H. longulus -group, but these have the hind margins of the metacoxal processes distinctly sinuate and the males in most cases have an asymmetric median lobe (cf. e.g. that of H. erzurumensis , Fig. 5 in Erman & Fery 2000).

Hydroporus longicornis is similar to H. neclae with respect to the habitus ( Fig. 2 ); the shape of the median lobe is also similar, but in ventral view much more distinctly narrowed before the apex in H. longicornis ( Fig. 5 ). The latter also has the hind margins of the metacoxal processes slightly sinuate and distinctly protruded backwards in the middle ( Fig. 13 ), while in the new species ( Fig. 12 ) each margin is almost straight and together they form an oblique angle as in H. melanarius . In addition, the surface of H. longicornis is less shiny than that of H. neclae since the reticulation is more strongly impressed in both sexes.

Notes: The drawings of the ventral aspect of the median lobe of H. longicornis in Schaeflein (1972: 31) and Nilsson & Holmen (1995: 54) are somewhat misleading since the narrowing before the apex is figured as too weak; this may be due to a slightly different angle of observation. Foster & Angus (1985: 12), Friday (1988: 83), and Fery (1999: 257) provide more appropriate figures of the median lobe since the apex is figured in a more or less perpendicular view.

Finally, it shall be mentioned that we have also taken into consideration that the new species might be H. jacobsoni , a species which was described from the adjacent Caucasian mountains. The study of a female syntype revealed, however, that this latter species has strongly sinuate hind margins of the metacoxal processes and, thus, belongs to the longulus -group of genus Hydroporus .

Figures

FIGURES 1 – 3. Habitus. 1 — Hydroporus neclae sp. n. (holotype); 2 — H. longicornis (male; Germany, Bavaria); 3 — H. melanarius (male; Czech Republic, Bohemia).

FIGURES 4 – 13. 4 – 6 — Median lobe of aedeagus in ventral and lateral view. 4 — Hydroporus neclae sp. n.; 5 — H. longicornis (Germany, Bavaria); 6 — H. melanarius (Czech Republic, Bohemia). 7 – 9 — Left paramere. 7 — H. neclae sp. n.; 8 — H. longicornis; 9 — H. melanarius. 10 – 11 — H. neclae sp. n. 10 — gonocoxae; 11 — gonocoxosternum. 12 – 13 — Metacoxal processes. 12 — H. neclae sp. n. (holotype) 13 — H. longicornis (male; Germany, Bavaria).