Anthracus furvinus (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 : 523-527

Anthracus furvinus DARLINGTON, 1968 ( Figs 18-20 )

Acupalpus furvinus DARLINGTON, 1968: 74 (type locality: Papua New Guinea: Dobodura) Anthracus furvinus DARLINGTON: Lorenz 1998: 339 [world catalogue], 2005: 360 [world catalogue]

E x a m i n e d t y p e m a t e r i a l: Holotype: 13 ( MCZ) labelled “ Dobodura / Papua , N.G. / Mar-Jul, 1944 / Darlington "; "not furvus / det. Darlington / at B. M. 1947-48 / Notes p. 32"; [first line and "32" in last line hw], " Mers / 3" [hw], "3"; " Holotype / Acupalpus / furvinus D" [hw on red label]; "M.C.Z. / Holotype / 31391" [red label, last line hw]" and "pictogram of camera / Caribbian / Database / 2005".

Paratypes: 13, 4♀♀ ( MCZ) labelled “Dobodura / Papua , N.G. / Mar-Jul , 1944 / Darlington " ; " Paratype / Acupalpus / furvinus / Darl." [red label] and "M.C.Z. / Paratype / 31,391" [red label, last line hw], the male additionally with a label "3", and one female additionally with "Mers / ♀ " and one female with "K 27/1962". 1♀ ( BMNH) labelled "Para- /type" [circular label with yellow margin] ; “Dobodura / Papua , N.G. / Mar-Jul, 1944 / Darlington "; " Paratype / Acupalpus / furvinus / Darl." [red label] and "Brit. Mus. / 1975-567". 1♀ ( MCZ) labelled "Aitape / Brit. N.G. / Aug 1944 / Darlington " and " Paratype / Acupalpus / furvinus / Darl. " [red label] and "M.C.Z. / Paratype / 31,391" [red label, last line hw] .

All mentioned types additionally with my label " Anthracus / furvinus / ( Darlington, 1968) / det. B. Jaeger 2012, 2013 or 2014".

The paratype specimen from Lake Daviumbu mentioned in the description has not been studied.

R e d e s c r i p t i o n: General appearance as figured ( Fig. 18 ). Body length 3.5-4.6 mm (HT 4.6 mm); width 1.5-1.8 mm.

Head dark brown, blackish brown or almost black, without dark reddish spots posterior to eyes. Clypeus reddish to dark reddish, labrum and mandibles (inner margins and apices blackish) paler reddish. Pronotum dark brown to blackish brown, often slightly paler than head, with lateral margins, sometimes also middle part of base, apical margin and hind angles vaguely paler brownish. Elytra dark to blackish brown, leaving base, lateral margin and the first interval reddish brown. Legs and palpi dark yellowish brown, antennae brown, with first two antennomeres paler. Ventral surface mainly dark brown, with prosternum, metasternum, and sometimes also abdominal sternites somewhat paler. Upper surface shiny, pronotum weakly, elytra moderately iridescent.

Head ( Figs 18-20 ) including eyes 0.71-0.79 times as wide as pronotum, with eyes moderately prominent (head 1.53-1.60 times as wide as head between eyes). Labrum almost rectilinear or weakly rounded at apical margin. Mandibles medium sized, not distinctly prolonged and curved, left mandible faintly obtuse at apex, not thickened or truncate. Antennae 2.25-2.40 times as long as pronotum and 0.84-0.87 times as long as elytra. Microsculpture on labrum almost isodiametric or weakly transverse, on clypeus weakly transverse, on anterior half of head either partly obliterated or with lightly impressed isodiametric meshes, or with moderately impressed isodiametric meshes, on posterior half with more clearly impressed isodiametric meshes, becoming weakly to moderately transverse in front of pronotal anterior margin.

Pronotum ( Figs 18-20 ) 1.25-1.36 times as wide as long, 1.26-1.38 times as wide as head, widest in second quarter, lateral seta inserted at or a little posterior to beginning of second quarter. Apical margin almost rectilinear or weakly emarginate, lateral border reaching medial third. Anterior angles narrowly rounded at tips, weakly projecting forward. Sides convex in anterior half, rectilinearly narrowed to posterior angles, which are more or less widely rounded. Basal margin weakly arcuate medially, oblique to posterior angles. Lateral furrows evenly narrow in apical half or apical two thirds, becoming markedly widened at posterior third, where they are fused with the baso-lateral impressions. Baso-lateral impressions medium sized, clearly delimited from pronotal disc and median part of base, fused with basal and lateral margin. Basal impressions and other surface of pronotum impunctate. Median line fine, disappearing before reaching basal and apical margins. Anterior transverse impression obliterated. Microsculpture with very faintly impressed rudimentary lines and strongly transverse meshes on disc, at basolateral impressions and lateral furrows with distinctly impressed isodiametric to weakly transverse meshes.

Macropterous. Elytra ( Fig. 18 ) with sides weakly to moderately widened posteriorly, widest just posterior to middle, 1.48-1.54 times as long as wide, 2.60-2.82 times as long and 1.34-1.45 times as wide as pronotum. Elytral striae distinctly impressed and impunctate, scutellar striole long. Intervals weakly convex on disc, becoming narrowed and moderately convex at apex. Basal pore at beginning of scutellar striole present, interval 3 in third quarter with one setiferous pore, adjoining stria 2. Microsculpture on scutellum almost isodiametric, on elytral intervals almost obsolete, only here and there traces of very lightly impressed transverse lines visible.

Metepisterna at inner margin about 1.4 times longer than wide at basal margin. Prosternum medially with 6-9, and in front of apical margin with 4-8 longer setae. Prosternal process posteriorly with 3-5 long and distinct setae. Abdominal sternites 4-6 with distinct and dense pubescence, in sternite 4 often reduced laterally. Last visible abdominal sternite of males moderately emarginate and that of females almost rectilinear or very faintly convex at apex, at apical margin with two longer setae in males and four in females.

Protarsomeres 1-4 of males markedly dilated and with distinct, biseriately arranged adhesive hairs on ventral surface. Protarsomere 4 markedly bilobed. Mesotarsomeres 1-4 of males moderately dilated and with adhesive hairs on ventral surface, mesotarsomere 4 moderately bilobed. In females pro- and mesotarsomeres unmodified. Male profemora somewhat thickened in relation to females and with a row of closely arranged long and fine setae at upper inner margin.

Median lobe of aedoeagus ( Figs 21-23 ) with general appearance and structures of internal sac as figured. Apex in dorsal aspect markedly widened and asymmetric. Internal sac (dorsal aspect) composed of two large apical teeth, and a row of 10-12 medium sized teeth medially.

N o t e s o n v a r i a t i o n: The type specimens from Dobodura and Aitape, as well as the non-type specimens from Sepen show a considerable variation in size, pronotal shape and microsculpture. It might be that all differences fall in the normal range of variation of Anthracus furvinus . However more material, including males, particularly from Aitape and Sepen, are needed to clarify the individual variation of A. furvinus and to ensure that no similar species occurs in these localities.

C o m p a r i s o n s A. furvinus belongs to the Anthracus annamensis group due to its quadrisetose ligula and other characters. Within this species group it has closer relations to the taxa related to A. furvus ANDREWES which were recently revised ( JAEGER 2012). These species occur further north in continental SE Asia, India and Sri Lanka, and one occurs at the Sunda Islands of Java and Bali. A. furvinus can be easily separated from all these species by the peculiar chaetotaxy of the profemora with a row of closely arranged long setae at upper inner margin, and by the different shape of the median lobe of the aedoeagus with its characteristic asymmetric apex and the particular structures of the internal sac (figs 21-23). Externally, A. furvinus is rather similar to A. furvus and A. wrasei . It differs from both species by the less distinct and much finer microsculpture on disc of the pronotum, the almost obsolete microsculpture on elytral intervals (meshes fine and strongly transverse, but fully developed in A. furvus and A. wrasei ) and the shorter respectively broader elytra (EL/EW: A. furvinus <1.55, A. furvus > 1.54, A. wrasei > 1.61). From A. wrasei it differs also by the different colour of head without reddish spots behind eyes, and the ratio of elytra/pronotum length (EL/PL: furvinus <2.81, wrasei> 2.88). From A. glabrus LOUWERENS which has the southernmost distribution of the Oriental members of the A. furvus complex, A. furvinus can be separated externally by the ratio of elytra/pronotum length (EL/PL: A. furvinus <2.81, A. glabrus > 2.92) and the different microsculpture on pronotal surface (with more distinct and rough meshes in A. glabrus ).

D i s t r i b u t i o n A. furvinus is so far known only from Papua New Guinea. The records from Aitape (about 900 km W of Dobodura) based on a very small atypical female and those from Sepen (about 600 km NW of Dobodura) based on two females should be confirmed by males. In addition to the types two females from the following locality have been examined:

P a p u a N e w G u i n e a: Madang Province: Sepen vill n°2, IV. 1988, Van Stalle (2 - cBAE).

Figures

Figs. 18-20: Anthracus furvinus (DARLINGTON). Habitus, head and pronotum. (18, 20) Paratypes, PNG, Dobodura, (19) Holotype.

Figs. 21-23: Anthracus furvinus (DARLINGTON). Median lobe of aedoeagus, dorsal and lateral aspect. (21) Holotype; (22, 23) Paratype, PNG, Dobodura.