Scarodytes antoni, Fery & Šťastný, 2007

Fery, H. & Šťastný, J., 2007, Notes on the Scarodytes savinensis-complex with the description of two new taxa (Coleoptera: Dytiscidae), Linzer biologische Beiträge 39 (2), pp. 877-899 : 880-883

publication ID	https://doi.org/ 10.5281/zenodo.5416778
persistent identifier	https://treatment.plazi.org/id/03C387AA-D319-D905-A8B5-26B8FE52FC81
treatment provided by	Valdenar
scientific name	Scarodytes antoni
status	sp. nov.

Treatment

Scarodytes antoni View in CoL nov.sp.

Deronectes (Potamonectes) halensis (FABRICIUS) ; MÜLLER 1926: 292 (partim).

Scarodytes savinensis View in CoL ruffoi FRANCISCOLO View in CoL ; ANGELINI 1975: 60 (partim), 1978: 89 (partim). - FRANCISCOLO 1978: 176 (partim), 1979: 419 (partim).

Scarodytes ruffoi FRANCISCOLO View in CoL ; NARDI 1998: 75 (partim). - ROCCHI 2000: 13 (partim). - NILSSON 2003: 69 (partim).

T y p e l o c a l i t y: Hrvatska Republic (= Croatia), Istria, WSW Rijeka, SSW Vranja, N Boljunsko Polje, 45.2992N 14.1286E {16}. T y p e m a t e r i a l:H o l o t y p e:, " 8.6.2007 (HR = Croatia), Istria, WSW Rijeka, SSW Vranja, N Boljunsko Polje", "brook, 137 m, Fery leg., 45°17'57N 14°07'43''E, UTM: VL 31682 16647", " Holotype, Scarodytes antoni View in CoL sp. n., Fery & Šťastný det. 2007" [red, printed] {16} ( NMW).P a r a t y p e s:C r o a t i a:13, 16, same data as holotype ( CHF, CJS, XXX). 1, same data as holotype, but with additional DNA voucher reference number "MNCN-AC6" ( MNCN). 1, " Croatia, Rabac, Mór J. 20.6.1996 " {17} ( CJS). 1, "Istr. [= Istria] Quieto [= river Mirna ], 21.5.[19]33, Springer", "Tte. [= torrente = brook] Mulaz" [hw?] {15 GoogleMaps }; "Mulaz" in Italian = "Mulec" in Croatian, a tributary of river Mirna , SW Krasica, ca. 45.37N 13.67E ( MCTR). I t a l y: 1, "Prči Dol, bei Triest " [hw J. [G.] Müller]{14 GoogleMaps }; "Prči Dol" (Slovenian) = "Percedol" ( Italian ) ; NE Trieste, between Opicina and Monrupino , ca. 45.72N 13.80E GoogleMaps ; this should be the specimen cited in MÜLLER (1926: 292) ( MCTR). 1, " Trieste, 10.8.1935 " [hw?], " Hydroporus halensis F." [hw?] ( MCTR). 1, 1, " Trieste , 10.8.[1]935 [hw?]" ; both specimens immature, median lobe of male strongly damaged, only apex present, but nevertheless correctly identifiable (MCTR). All paratypes provided with a red printed paratype label. A d d i t i o n a l m a t e r i a l s t u d i e d: C r o a t i a: 1, male sex symbol, "Istr.

Quieto, 24.4.[19]35, Springer" [printed except date, most probably an original Springer label],

" Iugoslavia, Istria, Quieto , 1.IV.1935, leg. Springer " [label made by F. Angelini] ; specimen

damaged, inner parts of abdomen absent (Dermestids?) (CFA). 1, "Iugoslavia, Istria, Quieto,

1.IV.1935, leg. Springer" [label made by F. Angelini]; specimen strongly damaged, inner parts

absent (Dermestids?) (CFA).

D e s c r i p t i o n: Habitus: Body elongate oval, more or less evenly vaulted; lateral outline with a slight discontinuity in dorsal view. Dorsal surface yellowish to reddish, with black spots on head and pronotum, and vittae on elytra.

C o l o u r a t i o n: Head and pronotum slightly more reddish yellow than elytra. Head next to inner side of each eye with a blackish spot of varying shape; spots reaching anteriorly margin of clypeus and posteriorly fused with black vertex. Pronotum with anterior margin somewhat transparent and thus appearing dark brownish since black vertex of head shining through; posterior margin narrowly blackish; disc with two large black spots, weakly variable in size; lateral rim slightly darkened, in particular posteriorly.

Elytra with suture narrowly darkened over entire length; base of elytra narrowly blackish; each elytron with up to seven dark brown to black, partly fused longitudinal vittae, however, only four of them on disc more or less complete; lateral ones considerably reduced or even absent. Three innermost vittae anteriorly shortened, only fourth vitta reaching base of elytra; second vitta anteriorly longer than first and third, first one distinctly shorter than second and third. Fifth vitta reduced to two longitudinal spots, sixth vitta reduced to a single spot beside anterior one of fourth vitta or totally absent; seventh vitta parallel to elytral margin, usually starting before elytral midlength, posteriorly fused with sixth vitta, apically not fused with ends of first, second and fourth vittae, rarely fused with end of third. First to third vittae fused shortly before and shortly behind middle of elytral length, in some specimens also fused with fourth vitta.

Ventral surface largely black; labrum, gula, sides of prosternum, prosternal process behind middle of procoxae, centre of metasternum and apical part of metacoxal processes reddish brown; hind margins of abdominal sterna shining through, brownish; last ventrite often lighter in larger extent. Epipleura yellowish; legs predominantly reddish brown, pro- and mesotarsomeres darker brown on upper side; mesotarsomeres darkened apically. Posterior margin of profemora, and anterior margin of meso- and metafemora diffusely darkened; metatibia in posterior half darkened on upper side. Antennomeres progressively darkened apically beginning with sixth antennomere; last palpomeres darkened apically. Epipleuron yellowish in anterior half, behind slightly darkened.

S t r u c t u r e: Clypeus with two impressions between eyes. Base of pronotum as wide as base of elytra or rarely slightly broader; lateral margins almost evenly rounded over entire length; maximum width short before or at posterior angles; posterior angles shortly rounded. Rim at sides of pronotum distinct, broad near anterior angles, becoming smaller in posterior half ( Fig. 9 View Figs 9-14 ). Pronotum with a small and indistinct impression near each anterior angle; in posterior two thirds with a distinct longitudinal impression parallel to each side, broadened and flattened before base; between impression and side broadly bulged. These longitudinal impressions particularly deepened at outer margins of large black spots, often groove-like but never as deep and distinct as e.g. in Oreodytes. Elytra slightly constricted near shoulders in dorsal view, sides less rounded in anterior two thirds than behind, maximum width before midlength. Lateral margins weakly ascending to humeral angles in lateral view, epipleura visible but short before shoulders.

Prosternal process weakly vaulted between procoxae but without a distinct transverse ridge; lanceolate, with rather flat longitudinal carina, flat sides and indistinct lateral beading behind procoxae. Metacoxal lines divergent anteriorly, ending shortly before posterior margin of metaventrite (metasternum). Third antennomere slightly shorter than fourth, both shorter than second and fifth. Protibia with outer margin weakly curved outwards apically ( Fig. 17 View Figs 17-22 ), a character which separates S. antoni (and S. ruffoi ) not only from S. savinensis but also from S. halensis .

S u r f a c e s c u l p t u r e: Head weakly microreticulated, shiny; reticulation interspersed with sparse punctation of two different diameters; coarser punctures sparser on clypeal disc; vertex not punctured.

Surface of pronotum shiny, sides broadly appearing matt due to very strong structure; weak microreticulation present near anterior margin, absent on disc, here shiny; disc densely punctate, diameter of punctures equal to that of coarser ones on head, distance between these at most equal to their diameter; before anterior margin with a row of very coarse punctures; laterally densely punctured and irregularly wrinkled. Centre of pronotal disc in most specimens with short longitudinal scratch.

Elytra on entire surface densely and evenly punctate, punctures slightly smaller than small ones on pronotum, distance between them smaller than their diameter; nevertheless, elytra not matt but with silky shine. Each elytron with rather regular puncture line next to suture, present over entire length of elytron; five additional, mostly rather indistinct lines consisting of irregularly placed punctures: first discal line situated between first and second black vittae but present only in anterior third; second discal line more distinct than others, placed more or less on outer margin of second vitta, present until short before apex of elytron, becoming less impressed posteriorly; third discal line placed on fourth vitta, weakly impressed, disappearing behind elytral midlength; fourth line very irregular and indistinct, consisting of some punctures behind shoulders and some further ones in posterior half, placed between seventh vitta and margin of elytron.

Ventral surface without microreticulation except posterior margins of metacoxae, latter areas variable in extent. Head with gula shiny, anteriorly with some coarse punctures; genae densely covered with very small punctures, not shiny. Pronotal process between anterior margin of prosternum and procoxae very roughly sculptured, matt; behind shiny, punctation absent or indistinct. Rest of ventral surface shiny in large extent, although densely covered with large punctures, distance between punctures mostly somewhat smaller than their diameter; space between punctures smooth; a small area one each side of midline of metasternum not punctured. Punctation on middle of first and second ventrite less dense; last ventrite with particularly dense punctation near anterior margin and apically. Epipleura covered with very dense and fine punctation, appearing matt.

S e t a t i o n: Head without setae. Pronotum and elytra covered with fine, short, rather evenly distributed yellowish setae, less dense on sides of pronotum and becoming somewhat denser and longer near apex of elytra. On ventral side, lanceolate part of prosternal process with some setae beside carina; abdomen covered with indistinct, fine and sparse yellowish setae, becoming denser on last four ventrites; middle of third to fifth ventrite with some particularly long setae.

V a r i a b i l i t y: The variability of S. antoni mainly concerns the colouration: the spots on the head are rather variable in size (those on pronotum are surprisingly constant in size and shape); the extent of the elytral vittae towards the base varies; in particular, the lateral vittae vary strongly between (a series of) longitudinal spots and complete absence; the extent of the dark brown parts on the venter is also variable, but this may be due to various maturity stages.

: Basal three protarsomeres expanded (Fig. 23), underside provided with dense setae; mesotarsomeres expanded less than protarsomeres; protarsal claws (Fig. 26) distinctly prolonged, posterior one longer, slightly sinuate in dorsal view; in lateral view strongly curved near base and provided with a tooth, almost straight in central part and curved again at apex; anterior claw more evenly curved; mesotarsal claws only a little prolonged, evenly curved, both more or less equal in shape. Median lobe of aedeagus ( Fig. 1 View Figs 1-4 ) in ventral view evenly tapering to apex, here broadly rounded; in lateral view sinuate at apex; parameres as in Fig. 5.

: Brownish areas on ventral side often larger than in males, however, abdomen never totally reddish as e.g. in females of S. h. halensis. Pronotum with very weak microreticulation; punctation on elytra somewhat finer and denser, with recognisable traces of reticulation between punctures; thus females appearing slightly duller than males. Punctation on venter less impressed and sparser, particularly on metacoxae, reticulation on posterior margins of metacoxae on average more reduced, often absent. Last four ventrites at least partly with weak reticulation. Protibia somewhat narrower than in males, outer margin apically less curved ( Fig. 18 View Figs 17-22 ). Pro- and mesotarsomeres as well as pro- and mesotarsal claws not modified. Gonocoxosternum and gonocoxae as in Figs 15 and 16.

M e a s u r e m e n t s: TL: 4.1-4.5 mm, MW: 2.1-2.3 mm, TL/MW: 1.91-2.05.

M o l e c u l a r d a t a: A fragment of 480 bp of the mitochondrial gene rrnL (primers 16SaR - 16Sb, SIMON et al. 1994), obtained from the paratype voucher MNCN-AC6, is deposited in GenBank with accession number: EU156492 View Materials

D i s t r i b u t i o n: Croatia and Italy (Fig. 29); so far only known from Istria; modern records only from the Croatian part. The locality "Prči Dol" [= "Percedol"] NE Trieste is

less than 5 km apart from the Italian-Slovenian border. Thus, it seems likely that the species occurs also in the Slovenian part of the peninsula.

E c o l o g y: Little is known about the ecology and life history of the new species. The holo- and paratypes from Boljunsko Polje were collected in fine gravel and sand near the water edge in a brook with slowly running water, little submerged vegetation and a maximum depth of ca. 50 cm at the site. It has a maximum width of about 3 m, with the bed situated between larger rocks; it appeared that the brook should have more water in spring but might dry up in summer. The specimens were collected together with Deronectes moestus inconspectus (LEPRIEUR 1876), but no other Hydradephaga were present. The paratype from Rabac was found in the bed of a small brook which runs from Labin to Rabac; at the time of collecting (end of June) this brook was almost dry and consisted of only few isolated pools on limestone (J. Mór, personal communication). The brook was entirely dried-up when the senior author visited it in early June 2007.

The brook near Boljunsko Polje is a tributary of the river Boljunšćica, which is seemingly canalised into tubes several kilometres more south, and lead to a power plant at Plomin Luka; the water finally flows into a gulf called "Kvarner". The small brook at Rabac also flows into the "Kvarner", and the Mirna river (= fiume Qieto) flows into the Adriatic Sea at Novigrad (= former Cittanova).

Except one male, all specimens from Boljunsko Polje were fully coloured. However, some specimens were slightly immature and thus not fully sclerotised.

D e r i v a t i o n o m i n i s: The new species is named after Anton Fery, the younger grandson of the senior author.