Hygrotus (Leptolambus) natrun, Fery, 2024

Hygrotus (Leptolambus) natrun nov.sp.

? Hydroporus lernaeus SCHAUM, 1857 ; SHARP 1882: 405 (partim).

? Coelambus parallellogrammus lernaeus ( SCHAUM, 1857) ; BEDEL 1895-1925: 339, footnote (partim).

Coelambus lernaeus ( SCHAUM, 1857) ; RÉGIMBART 1895: 35 (partim); ZIMMERMANN 1919: 151 (partim); 1920: 68 (partim); 1930: 101 (partim); GUIGNOT 1959: 332 (partim); ALFIERI 1976: 33.

Hygrotus (Coelambus) lernaeus ( SCHAUM, 1857) View in CoL ; ZALAT et al. 2000: 26; NILSSON 2001: 207 (partim); 2003: 72 (partim).

Hygrotus (Leptolambus) lernaeus ( SCHAUM, 1857) View in CoL ; NILSSON & HÁJEK 2024a: 46 (partim); 2024b: 197 (partim).

T y p e l o c a l i t y: Wadi El Natrun (also Wadi Natrun, Wadi an-Natrun, Wadi Natroun), ca. 100 km NW Cairo, ca. 30.41N 30.30E. N o t e s: This wadi is about 25 m below sea level and about 38 m below the level of the Nile.

M a t e r i a l e x a m i n e d: Holotype: ♀, " Wadi Natroun , 2.5.[19]27" [hw Guignot], " Coll. Alfieri, Egypte " [printed], " ♀ ", "Muséum Paris, 1960, Coll. F. Guignot " [printed] ; " Holotype, Hygrotus (Leptolambus) natrun nov.sp., H. Fery det. 2024" [red, printed] ( MNHN) [for labels see Fig. 1 View Fig ; specimen until now kept in coll. Guignot under Coelambus lernaeus var. orthogrammus ] . Paratypes: 2♁♁, "Ägypten 27.9.1982, Wadi Natrun, Kafr Daoud, Sattm." [hw?] ( NHMW, CHF). 2♁♁, " Bahariva Oases, 20.–24.3 [19]25" [printed], " Egypt, Min. Agric. ( Egypt), Coll. A. Alfieri " [printed], " Coll. Gschwendtner " [printed], " lernaeus SCHAUM. , det. Gschwendtner " [first line hw, second line printed] ( OLML). 1♀, " Egypt, W Desert Oasis Bahariva [= Bahariya, ca. 28.33N 29.00E, ca. 300 km SW Cairo], 30.IV.1996 W.G. Ullrich " [printed] ( CLH). 1♀, " Kairo " [hw Zimmermann], " Samml. A. Zimmermann " [printed], " Coelambus, lernaeus, (SCHAUM) , Fery det. 19[91] [hw Fery], "SNSB-ZSM Coleoptera, ID No. 000124" [printed] ( ZSM). All paratypes provided with the respective red label GoogleMaps .

D e s c r i p t i o n o f t h e h o l o t y p e:

H a b i t u s elongate oval, sides evenly rounded ( Fig. 1 View Fig ), body outline in dorsal view without distinct discontinuity at shoulders. Maximum width near midlength of body. Elytra brownish yellow, with blackish longitudinal vittae. Head and pronotum more reddish yellow, with brownish spots. Entire dorsal surface shiny although weakly reticulated in part.

H e a d: Anterior margin medially almost straight, but appearing semicircular if observed in perpendicular view on entire body of specimens because anterior margin not visible; anteriorly between eyes with two clypeal grooves. Whole surface finely reticulated, but not matt. Third and fourth antennomeres equal in length, thinner and shorter than first and second as well as rest of them. Punctation on clypeus fine and sparse, diameter of punctures that of one mesh, distance between punctures that of about 5 meshes; on frons punctures larger, diameter that of about three meshes, distance that of about three meshes; on vertex punctures again smaller and sparser; in clypeal groves punctures very dense; line of coarse punctures alongside inner margin of eyes. Clypeus with two ill-defined, brownish interocular spots; above insertions of antennae (between clypeal grooves and anterior margin) shining through brownish; vertex dark brownish. Antennae reddish-yellowish with antennomers progressively darkened distally, beginning with fifth.

P r o n o t u m: Sides slightly rounded, with distinct brownish rim; posterior angles more or less right-angled. Punctation on disc rather fine (as on clypeus), becoming coarser laterally; centre of disc with one small longitudinal puncture; directly behind anterior margin punctation very fine and sparse, but then before disc very coarse; before posterior margin again very coarse; near lateral margins punctation much denser. Few coarser punctures near margin with extremely short seta. Surface of pronotum smooth and shiny, but directly behind anterior margin distinctly reticulated and matt. Disc with one large ill-defined, brownish spot; anterior margin appearing dark brownish because dark vertex of head shining through.

E l y t r a: In dorsal view lateral margin of elytron visible only near elytral base and before apex because else sides of elytra turned inwards. Epipleural rim in lateral view weakly ascending towards humeral angle. Surface smooth in anterior two thirds, behind reticulated, but not distinctly matt. Punctation double; coarse punctures interspersed with small punctures; coarse punctures progressively becoming more numerous posteriad, but near apex punctures smaller. Each elytron in anterior half with two indistinct puncture lines, which coincide more or less with second and fourth vittae; in anterior quarter between fifth vitta and elytral margin some larger punctures indicating a third line; no sutural line perceptible. Most coarser punctures with very short seta, almost imperceptible on disc, otherwise slightly longer; in posterior half a very few punctures with a longer seta; however, generally setation only well visible if adequately illuminated. Each elytron with suture, four discal vittae, a lateral and a submarginal vitta blackish; elytral base medially with blackish stripe. Second vitta reaching base, fourth vitta ending just before base, first and third vittae ending far before base; lateral vitta short, only present in anterior half, and ending far before base; submarginal vitta present only in posterior half, more or less parallel to elytral margin, reaching until apex, and here fused with sutural line. First, second and third vittae fused just before apex, third and fourth vittae short behind midlength of elytra.

V e n t r a l s u r f a c e: Head, prosternum, epipleura and legs light brownish, metaventrite and abdomen predominantly black; metacoxal processes apically, neighbouring small parts of metacoxal plates, first abdominal ventrite, hind margins of third to fifth abdominal ventrites and sixth abdominal ventrite apically shining through brownish. Almost entire venter reticulated, only slightly shining, but not distinctly matt; metaventrite medially without reticulation and here more shiny; small brownish parts of metacoxal plates neighbouring apex of metacoxal processes smooth and shiny. Punctation on metacoxal plates and metaventrite distinct; on metaventrite punctures somewhat larger; punctures absent in small posterior part of metacoxal plates and on areas right and left of medial part of metaventrite; medial part of metaventrite with irregular lines of small punctures; metacoxal processes with sparse small punctures. Abdominal ventrites generally punctured; punctures progressively becoming smaller to last ventrite; second and third ventrites medially fused and here with only very few small punctures. Third to fifth ventrites medially with few densely arranged punctures, these with long and backwardly directed setae. Prosternal process ( Fig. 2 View Figs 2-3 ) lanceolate, longitudinally carinate, with tectiform cross section; apex rounded, sides slightly flattened and here with some punctures, lateral margin rimmed (for comparison see flat process of H. (L.) orthogrammus in Fig. 3 View Figs 2-3 ); prosternal column coarsely punctured with small transverse elevation between anterior coxae; medial part of prosternum (before column) vaulted and very coarsely sculptured. Epipleura in anterior third more or less as broad as apex of mesotibia, with some punctures and extremely weak reticulation; evenly narrowed behind; humeral part of epipleura with oblique carina delimiting genicular fossa; carina forming with epipleural rim an angle of about 25° (see details in VILLASTRIGO et al. (2017)). Hind margins of metacoxal processes slightly slanted, interlaminary bridge well exposed, forming a more or less triangular (or wing-like shaped) elevation on first and second abdominal ventrites (see details in FERY & RIBERA (2018)). Metacoxal lines diverging forwards, ending before hind margin of metaventrite. Protarsal claws thin, evenly curved and more or less identical.

G e n i t a l i a: Gonocoxae in ventral view as in Fig. 4 View Figs 4-12 ; in lateral view ( Fig. 5 View Figs 4-12 ) distinctly flatter than in H. (L.) lernaeus ( Fig. 8 View Figs 4-12 ); proximal portion less curved upwards than in H. (L.) lernaeus ( Figs 7, 8 View Figs 4-12 ), but more than in H. (L.) orthogrammus ( Figs 10, 11 View Figs 4-12 ); distal margins slightly concavely emarginate (see arrow in Fig. 4 View Figs 4-12 ). Gonocoxosternum as in Fig. 6 View Figs 4-12 ; differences to those of H. (L.) lernaeus ( Fig. 9 View Figs 4-12 ) and H. (L.) orthogrammus ( Fig. 12 View Figs 4-12 ) present, but irrelevant for diagnostic purposes.

M a l e s: Externally similar to females, but pro- and mesotarsi broader and anterior (inner) claw of protarsi strongly enlarged and curved ( Fig. 22 View Figs 13-22 ). Median lobe of aedeagus in ventral and lateral view as in Figs 13 and 14 View Figs 13-22 ; apex simple, not bulged as in H. (L.) orthogrammus ( Figs 18 and 18a View Figs 13-22 ); left paramere as in Fig. 19 View Figs 13-22 . Medial part of median lobe in lateral view significantly thinner (see arrow in Fig. 14 View Figs 13-22 ) than in other two species (compare Figs 16 and 18 View Figs 13-22 ); corrugated membrane (see FOSTER & ANGUS (1985: 8)) extending less far distally (compare Figs 13, 15 and 17 View Figs 13-22 ); for comparison of parameres see Figs 20 and 21. View Figs 13-22

M e a s u r e m e n t s: TL: 3.7–4.25 mm, MW: 1.8–2.2 mm, TL/MW: 1.93–2.01 (holotype: TL: 3.9 mm, MW: 1.95 mm, TL/MW: 2.00).

V a r i a b i l i t y: The variation of external morphological characters of the specimens studied is scanty. Worth mentioning are only: the spots on head and pronotum and the elytral vittae can be more blackish; the degree of fusion of the elytral vittae can vary; the small brownish parts on metathorax and abdomen can be darker or even black; the areas with coarser punctures on pronotum can be extended more mediad. The variation in the shape of the median lobe is small, but in some specimens the corrugated membrane extends a little more distally (ventral view). The variation in the shape of the parameres is somewhat greater, particularly because the distal part may be slightly curved inward. This also applies to the other two species and therefore the shape of the parameres is more or less unsuitable for diagnostic purposes. N o t e s: The females studied have a shiny upper surface, but the existence of a matt morph cannot be excluded.

D i s t r i b u t i o n: Endemic to Egypt. In ALFIERI (1976: 33) is given: " in swamps around Cairo ". In ZALAT et al. (2000: 26) is given: " Nile valley & Delta, eastern & western desert. Months of abundance: April, July-August. Habitat: collected from margins of swamps and marshes of rich vegetation; fresh and brackish water. " (both under " lernaeus "). Unfortunately, I was not enabled to study respective material.

D e r i v a t i o n o m i n i s: The new species is named after the type locality.