Ablepton Frivaldszky

Paweł Jałoszyński, 2018, World genera of Mastigitae: review of morphological structures and new ecological data (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 4453 (1), pp. 1-119 : 14-20

publication ID	https://doi.org/ 10.11646/zootaxa.4453.1.1
publication LSID	lsid:zoobank.org:pub:866690A9-0462-4892-AE29-9AAC623F87B3
DOI	https://doi.org/10.5281/zenodo.5976930
persistent identifier	https://treatment.plazi.org/id/2161879C-FFCB-8A00-FF7A-36506249DB0E
treatment provided by	Plazi
scientific name	Ablepton Frivaldszky
status

Treatment

Ablepton Frivaldszky View in CoL

Ablepton Frivaldszky, 1877 View in CoL : 17. Type species: Ablepton treforti Frivaldszky, 1877 View in CoL (monotypy).

Diagnosis. Ablepton differs from other Leptomastacini in two unique apomorphies: anterolateral corners of head capsule (i.e. sides of clypeus at each mandibular base) forming rounded lobes projecting anterolaterad ( Figs 10– 11 View FIGURES 10–14 ); postmesocoxal foveae directed mesad ( Fig. 20 View FIGURES 18–21 ); and in a combination of synapomorphies that occur in some other tribes and genera, but never all together: head, pronotum and elytra uniformly covered with setae ( Fig. 1 View FIGURES 1–6 ); head subquadrate ( Fig. 10 View FIGURES 10–14 ); 'neck' region broader than half width of head ( Fig. 12 View FIGURES 10–14 ); postgenae with distinct longitudinal ridges ( Fig. 12 View FIGURES 10–14 ; lr); each mandible with a median mesal tooth ( Fig. 11 View FIGURES 10–14 ); median projections of anterior and posterior margins of setose impression of mesoventrite not meeting ( Fig. 24 View FIGURES 24–28 ); mesoscutellum subtriangular, with pointed tip ( Fig. 26 View FIGURES 24–28 ); metaventrite with median longitudinal carina ( Fig. 21 View FIGURES 18–21 ).

Characteristics. Adult. Body ( Figs 1–2 View FIGURES 1–6 ) small, 1.40̄2.10 mm in length, light to moderately dark brown, flattened, sparsely setose, setae mostly modified, either flattened and broadened but strongly elongate or very short and broad, leaf-like.

Head capsule ( Figs 10–12 View FIGURES 10–14 ) divided into large and exposed anterior part and smaller, subcylindrical 'neck' region retracted into prothorax and demarcated by distinct occipital constriction; 'neck' region broader than half width of head. Anterior part of head flattened and about as long as broad or slightly longer, subquadrate in shape, with rounded sides of vertex, broadest behind middle but far from posterior margin. Composite eyes ( Fig. 10 View FIGURES 10–14 ; ce) slightly anterior to middle, on sides of head, vestigial, each composed of 2̄3 small ommatidia which are barely discernible under stereoscopic microscope. Vertex transverse, convex, with posterior margin nearly straight at middle and a pair of large lateroposterior setiferous punctures ( Fig. 10 View FIGURES 10–14 ; sp). Tempora long and rounded. Frons between antennal insertions subtriangular, anteriorly demarcated by deep and narrow frontoclypeal groove ( Fig. 10 View FIGURES 10–14 ; fcg), which is obliterated laterally. Clypeus transverse, with subtriangular and rounded lateral projections behind external margin of each mandibular base. Antennal insertions ( Fig. 10 View FIGURES 10–14 ; ai) laterodorsal, in submedian area of head. Gular plate ( Fig. 12 View FIGURES 10–14 ; gp) lacking sutures, with transverse reticulation; posterior tentorial pits ( Fig. 12 View FIGURES 10–14 ; ptp) C-shaped and located in front of transverse impression demarcating 'neck' region ventrally. Head densely but finely punctate and covered with sparse flat, broad and moderately long setae.

Antennae ( Figs 1–2 View FIGURES 1–6 , 12, 14 View FIGURES 10–14 ) much shorter than body; scape ( Fig. 12 View FIGURES 10–14 ; sc) only 3̄4 times as long as broad; pedicel only slightly longer than antennomere III and distinctly broadening from relatively narrow base to apex; antennomeres III–X ( Fig. 14 View FIGURES 10–14 ) mostly transverse and thickening distad, each with short and narrow stalk and sharp basal ring, antennomeres covered with dense and evenly distributed short and only slightly flattened setae and much longer, strongly flattened and broadened sparse setae around distal margin of each antennomere except I, II and XI, all setae inserted on small papillae, so that surface of antennomeres appears coarse.

Labrum ( Figs 10–11 View FIGURES 10–14 ; lbr) strongly transverse, with slightly rounded and anteriorly divergent lateral margins and concave anterior margin with deep median subtriangular emargination; dorsal surface with only several long and thick setae. Mandibles ( Figs 10–12 View FIGURES 10–14 ) symmetrical, each subtriangular but relatively slender, with broad base and long, curved and moderately sharp apical tooth; mesal tooth ( Figs 10–11 View FIGURES 10–14 ; mt) present, subtriangular and shifted dorsad; setose prostheca ( Fig 11 View FIGURES 10–14 ; pst) present, small. Maxilla ( Figs 15–16 View FIGURES 15–17 ) with large and nearly semicircular cardo ( Fig. 15 View FIGURES 15–17 ; cd); basistipes ( Fig. 15 View FIGURES 15–17 ; bst) subtriangular and elongate; mediostipes ( Figs 15–16 View FIGURES 15–17 ; mst) large and sharply demarcated from lacinia ( Figs 15–16 View FIGURES 15–17 ; lac) and galea ( Figs 15–16 View FIGURES 15–17 ; gal), which are both elongate and curved mesad and each bears a dense row of flattened distal setae; palpifer ( Figs 15–16 View FIGURES 15–17 ; ppf) broad and elongate; maxillary palp ( Figs 15– 17 View FIGURES 15–17 ) composed of minute palpomere I ( Figs 15–16 View FIGURES 15–17 ; mxp1), elongate and broadening distad palpomere II ( Figs 15, 17 View FIGURES 15–17 ; mxp2), and palpomeres III ( Fig. 17 View FIGURES 15–17 ; mxp3) and IV ( Fig. 17 View FIGURES 15–17 ; mxp4) forming large compact oval in which palpomere III is pedunculate and with strongly oblique apex and palpomere IV is broader than long and broadly subconical with rounded but distinctly marked apex. Labium ( Fig. 15 View FIGURES 15–17 ) with broad submentum ( Fig. 15 View FIGURES 15–17 ; smn) posteriorly not demarcated from gular region and laterally indistinctly demarcated from postcardinal portions of hypostomae by weakly marked and incomplete ridges; mentum ( Fig. 15 View FIGURES 15–17 ; mn) subtrapezoidal with anterior margin slightly concave; prementum ( Figs 15–16 View FIGURES 15–17 ; pm) long, subtrapezoidal, broadest distally, without demarcated ligula, with broadly separated bases of labial palps; lateral lobes of hypopharynx ( Fig. 15 View FIGURES 15–17 ; lhl) moderately large; labial palp composed of three palpomeres: palpomere I ( Fig. 15 View FIGURES 15–17 ; lp1) small, elongated, palpomere II ( Fig. 15 View FIGURES 15–17 ; lp2) largest, strongly elongated and broadened distally, palpomere III ( Fig. 15 View FIGURES 15–17 ; lp3) narrow, long and pointed. All mouthparts and clypeus covered with sparsely distributed porous fields ( Fig. 13 View FIGURES 10–14 ; pf); maxillary palpomeres IĪIV covered with elongate and only slightly broadened and flattened setae ( Fig. 17 View FIGURES 15–17 ).

Prothorax ( Figs 1–2 View FIGURES 1–6 , 18–19 View FIGURES 18–21 ) flattened and elongate, broadest near anterior third. Pronotum with all margins rounded; anterior corners not marked, posterior corners distinct, obtuse-angled; pronotal base lacking pits, impressions, grooves or carinae. Prosternum ( Figs 18–19 View FIGURES 18–21 ) with basisternal part ( Figs 18–19 View FIGURES 18–21 ; bstr) about as long or only slightly longer than coxal part ( Fig. 19 View FIGURES 18–21 ; cxst), laterally completely fused with hypomera and lacking any noticeable traces of notosternal sutures. Coxal region demarcated anteriorly by rounded carina extending laterally up to apices of subtriangular postcoxal hypomeral lobes ( Fig. 18 View FIGURES 18–21 ; pchl) projecting mesad. Procoxal cavities broadly open; profurcal foveae ( Fig. 10 View FIGURES 10–14 ; pff) small but distinct. Prosternal intercoxal process ( Fig. 19 View FIGURES 18–21 ) subtriangular and posteriorly very narrow, diffuse, indistinctly demarcated laterally and very weakly elevated, so that procoxae are not separated. Ventral surface of prothorax largely asetose and glabrous; short, broad and strongly flattened setae present along anterior and posterior margins of basisternal area ( Figs 18–19 View FIGURES 18–21 ).

Mesoventrite ( Figs 20–24 View FIGURES 18–21 View FIGURES 22–23 View FIGURES 24–28 ) subtrapezoidal, broadening posteriorly. Prepecti ( Fig. 21 View FIGURES 18–21 ; pre) long and together with anteromedian mesoventral area forming continuous 'collar', with a narrow and shallow transverse groove just behind its anterior ridge ( Fig. 21 View FIGURES 18–21 ; ar) and deeply bisinuate posterior margin with rounded and asetose subtriangular posteromedian expansion. Region just behind collar strongly and abruptly constricted laterally and impressed medially, forming a transverse setose impression ( Figs 20–23 View FIGURES 18–21 View FIGURES 22–23 ; si) filled with dense, strongly flattened, leaf-like setae. Posterior margin of setose impression forming a large median subtriangular projection directed anterad, but not meeting with anterior projection of collar. Mesoventral intercoxal process ( Fig. 21 View FIGURES 18–21 ; msvp) long, narrow and weakly convex, fully separating mesocoxae, slightly narrowing posteriorly and fused with metaventrite. Mesanepisterna ( Fig. 23 View FIGURES 22–23 ; aest2) large and subtriangular, demarcated from mesepimera by carinate ridge; mesepimera ( Fig. 23 View FIGURES 22–23 ; epm2) indistinctly demarcated from metepimera and partly exposed in ventral view ( Fig. 21 View FIGURES 18–21 ).

Mesonotum with subtriangular and pointed mesoscutellum ( Fig. 26 View FIGURES 24–28 ; scl2) not visible between elytral bases in intact specimens, scutoscutellar suture absent.

Metaventrite ( Figs 20–22 View FIGURES 18–21 View FIGURES 22–23 ) short, subtrapezoidal, broadest at level of metacoxae, with lateral margins rounded; mesocoxal cavities with nearly continuous marginal carina encompassing nearly entire cavity except for its external portion; posterior margin of metaventrite deeply bisinuate laterally in admetacoxal region and with a broad metaventral intercoxal process ( Fig. 21 View FIGURES 18–21 ; mtvp) with nearly straight posterior margin and subtriangular lateral corners weakly projecting posteriorly; metaventrite with median longitudinal carina ( Fig. 21 View FIGURES 18–21 ; mc) and three pairs of foveae, whose openings are filled with leaf-like setae: lateral meso-metaventral foveae ( Figs 20–23 View FIGURES 18–21 View FIGURES 22–23 ; lmf) laterad mesocoxal insertions; lateral mesocoxal foveae ( Figs 20 View FIGURES 18–21 ; 22 View FIGURES 22–23 ; lmcf) posterolaterad mesocoxal insertions; and postmesocoxal foveae ( Figs 20–24 View FIGURES 18–21 View FIGURES 22–23 View FIGURES 24–28 ; pmcf) posterad mesocoxal cavities, in submedian region of ventrite. Admetacoxal margin of metaventrite with a short thickening demarcated by a groove, forming adcoxal carina ( Fig. 21 View FIGURES 18–21 ; acxc). Metanepisterna ( Figs 20–21 View FIGURES 18–21 , 23 View FIGURES 22–23 ) partly visible in ventral view, relatively narrow, distinctly broadening posterad; metepimera ( Fig. 23 View FIGURES 22–23 ; epm3) about three times as broad as metanepisterna, with indistinctly demarcated inner and outer component, posteriorly extending far behind metacoxae.

Metendosternite (metafurca) Y-shaped, with very short but distinct stem and divergent lateral furcal arms ( Fig. 20 View FIGURES 18–21 ; lmfa), additionally with a short anteromedian projection.

Legs ( Figs 1–2 View FIGURES 1–6 , 21 View FIGURES 18–21 , 25, 28 View FIGURES 24–28 ) moderately long, robust. Pro- and mesocoxa short subconical, metacoxa with a nearly hemispherical basal part and subconical distal part. Mesocoxa ( Fig. 25 View FIGURES 24–28 ; cx2) with impressed lateral adtrochanteral area, border between concave and convex surface with a row of 3̄5 long coxal bristles ( Fig. 25 View FIGURES 24–28 ; cxb). All trochanters short and subtriangular. Femora weakly clavate. Tibiae robust, all nearly straight. Tarsi short, subcylindrical, tarsomeres reducing in length but not in width from I to IV, tarsomere V strongly elongate, with curved and slender claws and empodium with a pair of modified empodial setae.

Elytra ( Figs 1–2 View FIGURES 1–6 , 26 View FIGURES 24–28 ) oval, flattened, lacking humeral calli and basal impressions, with rounded apices; elytral disc with large and deep punctures arranged in nearly complete longitudinal rows.

Hind wings absent.

Abdomen ( Fig. 20 View FIGURES 18–21 ) with sternite III not fused with metaventrite, about as long as sternites IV and V together; sternite VIII in male with rounded posterior margin. Sternite III with distinct anteromedian and indistinct anterolateral (postmetacoxal) impressions filled with leaf-like setae.

Aedeagus (illustrated in (Jałoszyński et al. (2015, 2018)) symmetrical and lightly sclerotized, strongly elongate, parameres partly fused to lateral walls of median lobe, with apices strongly curved mesad; flagellum simple and broad, not coiled. Ejaculatory duct with strongly elongate and narrow sperm pump, its distal end with a sclerotized funnel-like collar.

Spermatheca (not illustrated) globular and thick-walled, nearly spherical, with 'stalk' as long as globular part and as broad as 1/3 of globular part; ductus spermathecae and duct of accessory gland inserted into the stalk.

Sexual dimorphism expressed in protrochanters, which in males are subquadrate and with a subtriangular ventral (posterior) projection ( Fig. 27 View FIGURES 24–28 ).

Larva. Unknown.

Composition and distribution. Only three species are known (but see Remarks), distributed in Romania and Serbia ( Fig. 7 View FIGURES 7–9 ).

Natural history. Some of the Serbian species of Ablepton were collected by pitfall traps with vinegar placed between roots of old beech trees on a limestone-rich ground near a stream, some others in vicinity of caves. Specimens of Ablepton treforti studied by the author were obtained by sifting leaf litter in beech forests in Romania. Nothing else is known about the natural history of this genus.

Remarks. Within Leptomastacini , Ablepton closely resembles Taurablepton . These genera can be distinguished on the basis of the following characters: the shape of head (subquadrate in Ablepton vs. subtriangular in Taurablepton ); anterolateral corners of head capsule at each mandibular base (forming rounded lobes projecting anterolaterad in Ablepton vs. not projecting in Taurablepton ); median projections of anterior and posterior margins of setose impression of mesoventrite (not meeting in Ablepton vs. nearly touching in Taurablepton ); postmesocoxal foveae (directed mesad and very close to each other in Ablepton vs. directed anteromesad and broadly separated in Taurablepton ); the mesoscutellum (subtriangular with pointed tip in Ablepton vs. subtrapezoidal with truncate tip in Taurablepton ). Additionally, Ablepton has the median area of prosternum asetose, whereas in Taurablepton there are some median setae on the basisternal region.

The three species placed in Ablepton differ in so minor characters that they may in fact represent variability within one species. Nonveiller & Pavičevič (1990, 1999) stated that the two Serbian species do not differ in the structure of the aedeagus from the type species of the genus, A. treforti . Also external diagnostic characters of their newly described two Serbian species seem rather elusive. A larger material from the entire known distributional range of Ablepton must be studied to address this issue.