Acupalpus (Stenolophidius) papua, Darlington, 1968

Arlington, 2015, A new species of the Acupalpus subgenus Stenolophidius JEANNEL, 1948 from Papua New Guinea, and redescriptions of Acupalpus (Stenolophidius) papua DARLINGTON, 1968 and Anthracus furvinus DARLINGTON, 1968 (Coleoptera, Carabidae, Harpalini, Stenolophina), Linzer biologische Beiträge 47 (1), pp. 513-528 : 514-518

Acupalpus (Stenolophidius) papua DARLINGTON, 1968 ( Figs 1-8 )

Acupalpus papua DARLINGTON, 1968: 75-76 (type locality: Papua New Guinea: Dobodura) Anthracus papua DARLINGTON: LORENZ 1998: 339 [world catalogue], 2005: 360 [world catalogue]

T y p e m a t e r i a l e x a m i n e d: Holotype: 1 3 ( MCZ) labelled "Dobodura / Papua , N.G. / Mar-July, 1944 / Darlington "; "3"; "det. Darlington / at B.M. 1947-48 / Notes p."; "Mers /3" [hw]; " Holotype / Acupalpus / papua D" [hw on red paper]; "M.C.Z. / Holotype / 31392" [red paper, last line hw]; "Camera symbol / Aug-Dec 2006 / MCZ Image / Database". The holotype is in good condition, withouth missing appendages.

Paratypes: 4 33 ( MCZ) labelled "Dobodura / Papua , N.G. / Mar-July , 1944 / Darlington " ; " Paratype / Acupalpus / papua / Darl." [red paper] and "M.C.Z. / Paratype / 31392" [red paper, last line hw]. 1 specimen additionally with the label " Drawn 1966 / Mary Catron / no. 243". 1♀ ( MCZ) labelled "vic Hollandia / Dutch N.G. / July-Sept 1944 / Darlington " ; "Mers / ♀ " [hw] ; " Paratype / Acupalpus / papua / Darl."[red label] and "M.C.Z. / Paratype / 31392" [red paper, last line hw]. 13 ( BMNH) labelled “Para- / type" (circular label with yellow margin) ; "vic Hollandia / Dutch N.G. / July-Sept 1944 / Darlington " ; "Brit. Mus. / 1975-567" [last three letters hw] and " Paratype / Acupalpus / papua / Darl."[red label]. 13 ( MCZ) labelled " Oro Bay / Papua , N.G. / Dec' 43 - Jan' 44 / Darlington " ; " Paratype / Acupalpus / papua / Darl."[red label] and "M.C.Z. / Paratype / 31392" [red paper, last line hw].

All types additionally with my label " Acupalpus / ( Stenolophidius ) / papua / Darlington, 1968 / det. B. Jaeger 2012, 2013 or 2014".

R e d e s c r i p t i o n: General appearance as figured ( Fig. 1 ). Body length 3.6-4.2 mm (holotype 3.6 mm); width 1.6-1.8 mm.

Head dark brown to blackish brown, with clypeus dark brown, labrum and mandibles dark reddish brown, with inner margin and apices of the latter blackish. Pronotum paler than head, brown to dark brown, with lateral margin and area around hind angles yellowish brown. Elytra brown to dark brown, with apex, lateral margins, and sometimes also first interval indistinctly paler. Antennae with first two antennomeres dark yellowish, remaining ones brown. Palpi and legs paler to darker yellowish. Ventral surface mainly brown to dark brown, but pro- and metasternum often markedly paler reddish brown, and last, or last two abdominal sternites vaguely paler brown. Epipleura brown. Pronotum weakly, elytra clearly iridescent.

Head ( Figs 1-3 ) including eyes 0.79-0.83 times as wide as pronotum, with eyes large and markedly prominent (head 1.69-1.79 times as wide as head between eyes). Labrum, with apical margin weakly emarginate medially, not asymmetric. Left mandible moderately long, faintly obtuse at apex, not thickened or truncate. Antennae comparatively short, 2.50-2.65 times as long as pronotum and 0.80-0.87 times as long as elytra. Microsculpture distinct, on labrum with weakly transverse, on clypeus with almost isodiametric meshes, on frons and vertex with distinct isodiametric meshes becoming moderately transverse in front of pronotal apical margin.

Pronotum ( Figs 1-3 ) 1.42-1.49 times as wide as long, 1.21-1.26 times as wide as head, widest in second quarter, lateral seta inserted at beginning of second quarter. Apical margin almost rectilinear, faintly bordered laterally. Anterior angles narrowly rounded at tips, not or only weakly projecting forward. Sides convex in anterior half or two thirds and at posterior half or third rectilinearly converging to base, or very faintly sinuate in front of the latter. Posterior angles distinct and rather sharp at apices. Basal margin between posterior angles about 1.08-1.13 times as wide as apical margin between anterior angles, and 0.80-0.84 times as wide as maximum pronotal width, arcuate medially and oblique to posterior angles, not bordered at sides. Lateral furrows evenly wide in anterior half, becoming markedly widened in posterior half or third where they are fused with baso-lateral impressions. Baso-lateral impressions rather large and deep, clearly separated from the convex pronotal disc and median part of base, flattened to the markedly reflexed basal and lateral margins. Base with rather coarse and close punctation in the lateral impressions, between impressions impunctate or with only few single punctures. Pronotal surface at anterior quarter without punctation. Median line fine and impunctate, disappearing before reaching apical and basal margins. Anterior transverse impression at least suggested. Microsculpture with very lightly impressed strongly transverse meshes on disc, and weakly transverse to almost isodiametric meshes at baso-lateral impressions.

Macropterous. Elytra ( Fig. 1 ) 1.38-1.48 times as long as wide, 3.04-3.16 times as long and 1.46-1.52 times as wide as pronotum. Surface moderately convex. Sides moderately enlarged posteriorly, widest just behind middle, subapical sinuation moderate to distinct. Elytral striae weakly impressed and impunctate, scutellar striole long. Intervals rather flat and wide on disc, becoming somewhat narrowed and weakly convex in front of apex. Basal pore at beginning of scutellar striole present, interval 3 in third quarter with one setiferous pore, adjoining stria 2. Microsculpture on elytral intervals nearly obliterated, only here and there very lightly impressed transverse meshes and line rudiments visible. Scutellum and its nearest surrounding with isodiametric meshes.

Ventral side: Prosternum medially with 6-8 and in front of anterior margin with 3-4 long erect setae. Metepisterna at inner margin about 1.4 times as long as wide at basal margin. Abdominal sternite 2-3 medially, 4 at medial two quarters and 5-6 entirely with moderate pubescence. Last visible sternite in males with two and in females with four longer setae at apical margin.

Legs: Pro- and mesotarsomeres 2-4 of males with biseriately arranged adhesive hairs on ventral surface.

Aedoeagus ( Figs 4-8 ) medium sized, with lateral sclerotization markedly reduced at medial portion and in some specimens replaced by a reddish swelling or dilatation typical for members of Stenolophidius . The internal sac shows the characteristic ground composition of structures for a Stenolophidius species (see JAEGER 2013) without significant specific modifications.

C o m p a r i s o n s: A. papua is closely related to A. sinuellus BATES from continental SE Asia and represents probably a southern vicariant of the latter. Both species are rather similar in general appearance, colour and also in aedeagal features, the latter do not provide significant differences. However, though similar A. papua differs externally by the pronotal shape which is on average more transverse and has rather acute hind angles usually with sharp tips (in sinuellus more obtuse with tips usually narrowly rounded), the shorter elytra (EL/EW 1.38-1.48 in A. papua and 1.50-1.62 in A. sinuellus ) and the microsculpture on head which is rather distinct on frons (instead of obliterated or represented by mesh rudiments in A. sinuellus ).

From A. quadrisetosus nov.sp. which occurs sympatrically at least at Dobodura, A. papua differs by its larger size, the darker antennae which leaves only the first or the first two antennomeres yellowish (in A. quadrisetosus entirely yellowish), larger and strongly produced eyes, the more transverse pronotum, and the elytra which are longer (EL/PL: in A. quadrisetosus 2.85-2.89) and broader (EW/PW: in A. quadrisetosus 1.43-1.45) relative to pronotum.

From A. brunnicolor (SLOANE) which is not treated here (one syntype deposited in ANIC, has been examined by me), but occurs also in New Guinea, A. papua can be easily separated by the different colour and shape of the pronotum (reddish yellow, with widely rounded hind angles in A. brunnicolor ).

D i s t r i b u t i o n: The species is so far known only from Papua New Guinea. In addition to the type material one male from the following locality has been studied:

P a p u a N e w G u i n e a: Madang Province, Baiteta, canopy mission, light AR 27, VII. 1995, Missa (1 - cBAE)

This specimen agrees with the members of the type series in size, colour, microsculpture and general appearance, but differs slightly by the shape of the pronotum which is weakly narrower and longer.

Figures

Figs. 1-3: Acupalpus (Stenolophidius) papua DARLINGTON. Habitus, head and pronotum. (1, 3) Paratypes, PNG, Dobodura, (2) Holotype.

Figs. 4-8: Acupalpus (Stenolophidius) papua DARLINGTON. Median lobe of aedoeagus, lateral and dorsal aspect. (4, 7) Paratype, PNG, Hollandia; (5, 6, 8) Paratypes, PNG, Dobodura.