Acupalpus (Stenolophidius) quadrisetosus, Arlington, 2015

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 : 518-522

Acupalpus (Stenolophidius) quadrisetosus nov.sp. ( Figs 9-17 )

Acupalpus ustus ANDREWES : DARLINGTON 1968: 73, 75 [partim: specimens from Dobodura and Popondetta]

T y p e m a t e r i a l: Holotype: 3 ( MCZ) labelled "Dobodura / Papua N.G. / Mar-July, 1944 / Darlington ", "3", "ustus / det. Darlington / at B.M. 1947-48 / Notes p." [first line hw], "Mers 3" [hw], " Acupalpus / ustus Andr. / det. Darl. '66" and " HOLOTYPE 3 / Acupalpus / ( Stenolophidius ) / quadrisetosus sp.n. / des. B. Jaeger 2013 ". The holotype is in good condition without missing body parts.

Paratypes: 933, 15♀♀ (MCZ, cJAE) labelled "Dobodura / Papua N.G. / Mar-July, 1944 / Darlington" and " Acupalpus / ustus Andr. / det. Darl. '66", 13 additionally with "Mers. / ♀ ". 13 (RMNH) with same locality and identification labels, and additionally "Museum Leiden / ex. collection / C.J. Louwerens / rec. 1979" and " Acupalpus / ( Stenolophidius ) / ustus / Andrewes, 1930 / det. B. Jaeger 2011". 13 (BMNH) labelled "Dobodura / Papua N.G. / Mar-July, 1944 / Darlington" and " Acupalpus / ustus Andr. / det. Darl. '66". 13 (MCZ) labelled "NEW GUINEA: SE. / Popondetta, 60m / 30-31.VIII. '63" and "J. Sedlacek / Light Trap / BISHOP" and " Acupalpus / ustus Andr. / det. Darl. '69". 1♀ (MCZ) labelled "NEW GUINEA: SE. / Popondetta, 60m / 31.VIII.-2.IX. '63" and "J. Sedlacek / Light Trap / BISHOP" and " Acupalpus / ustus A. / det. Darl. '69".

All paratypes additionally labelled " PARATYPE 3 or ♀ / Acupalpus / ( Stenolophidius ) / quadrisetosus sp.n. / des. B. Jaeger 2013 ".

D e s c r i p t i o n: General appearance as figured ( Fig. 9 ). Body length 3.0- 3.4 mm (HT 3.3); width 1.3-1.5 mm.

Head blackish brown, with clypeus brown or dark yellowish brown, labrum and mandibles (tips darkened) paler to darker yellowish brown, palpi and antennae yellowish. The latter sometimes with antennomeres 4-11 with a thin longitudinal dark stripe. Pronotum dark brown or blackish brown, often paler than head and elytra, with apical margin and base laterally somewhat paler. Elytra blackish brown, with base, lateral margin and first interval paler reddish brown. Legs yellowish brown. Ventral surface mainly brown to dark yellowish brown, with head and proepisterna often darker brown. Pronotum weakly, elytra markedly iridescent.

Head ( Figs 9-11 ) including eyes, moderately wide, 0.75-0.80 times as wide as pronotum, with eyes moderately prominent (head 1.49-1.61 times as wide as head between eyes). Left mandible sharp to somewhat obtuse at apex, not thickened or truncate. Labrum at apical margin rounded, not asymmetric. Antennae rather short 2.33-2.50 times as long as pronotum and 0.81-0.86 times as long as elytra. Microsculpture on labrum with isodiametric, on clypeus with isodiametric to moderately transverse meshes, on frons with isodiametric meshes becoming somewhat transverse laterad, and on vertex posterior to eyes with faint and strongly transverse meshes.

Pronotum ( Figs 9-11 ) 1.34-1.41 times as wide as long, 1.26-1.33 times as wide as head, widest in second quarter, lateral seta inserted somewhat posterior to beginning of second quarter. Apical margin weakly to moderately emarginate, faintly bordered laterally. Anterior angles narrowly rounded at tips, weakly to moderately projecting forward. Sides convex in anterior two thirds, rectilinearly converging at posterior third, not or very faintly sinuate in front of pronotal base. Posterior angles distinct and sharp. Basal margin between posterior angles slightly wider as apical margin between anterior angles, and 0.78-0.81 times as wide as maximum pronotal width, weakly arcuate medially and almost straight or slightly oblique to posterior angles, not bordered at sides. Lateral furrows narrow, becoming widened and confluent with baso-lateral impression at basal half or third. Baso-lateral impressions rather large and deep, clearly delimited from the convex pronotal disc and the somewhat depressed middle portion of base, flattened to basal and lateral margin, which are weakly reflexed. Base with rather coarse, but not very close punctation in the baso-lateral impressions, sometimes extending somewhat forward along sides, between impressions impunctate or with few small punctures. Surface otherwise impunctate. Median line very fine, impunctate, disappearing before reaching apical and basal margins. Anterior transverse impression obsolete or only suggested. Microsculpture strongly obliterated, only here and there traces of fine transverse lines are visible, which are more distinct at baso-lateral impressions.

Macropterous. Elytra ( Fig 9 ) 1.38-1.44 times as long as wide, 2.80-2.95 times as long and 1.43-1.51 times as wide as pronotum. Sides weakly to moderately widened posteriorly, widest behind middle, subapical sinuation moderate. Elytral striae weakly impressed and impunctate, scutellar striole long. Intervals rather flat and wide on disc, becoming 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 only with indistinct traces of transverse lines, scutellum with almost isodiametric meshes.

Ventral side: Prosternum medially with six longer erect setae. Metepisterna comparatively short, though distinctly narrowed posteriorly, at inner margin about 1.3 times longer as wide at basal margin. Abdominal sternite 4-6 usually moderately pubescent, in sternite 4 pubescense lacking laterally. Last visible sternite in males and females with four longer setae at apical margin.

Legs: Protarsomeres 2-4 and mesotarsomeres 3-4 of males with biseriately arranged adhesive hairs on ventral surface.

Aedoeagus ( Figs 12-17 ): Comparatively small, with typical reduced lateral sclerotization which is replaced by a reddish swelling or dilatation in some specimens. Internal sac with no significant specific structures.

C o m p a r i s o n s a n d r e m a r k s A. quadrisetosus nov.sp. was reported as A. ustus ANDREWES from Papua New Guinea (specimens from Dobodura and Popondetta) by DARLINGTON (1968: 75) who noted "My identification is tentative, although based on comparison of specimens with the type." A. quadrisetosus is in general appearance actually rather similar to A. ustus ANDREWES from Sumatra and Kalimantan and represents obviously a closely related southern vicariant of the latter. It differs from A. ustus by the generally darker body with head blackish instead of reddish or brown, pronotum dark brown instead of reddish or pale brown and elytra blackish brown instead of reddish to dark brown, the microsculpture on frons of head which is much more distinct (very lightly impressed and partly obliterated in A. ustus ), the eyes which are weakly smaller (HW/HWbE in A. quadrisetosus mostly <1.60 in A. ustus > 1.58), the pronotum which is broader relative to head (PW/HW> 1.25, in A. ustus <1.26), the elytra which are broader and shorter (EL/EW <1.45, in A. ustus > 1.43), and the chaetotaxy of the anal sternite, which is at apical margin quadrisetose in males of A. quadrisetosus instead of bisetose in males A. ustus . However, the latter character needs verification because it might be that in the two old paratype male specimens of A. ustus the outer two setae were broken, though I was not able to detect any insertion pore. The median lobe of the aedoeagus is rather similar in both taxa but in A. quadrisetosus it is more clearly curved ventrad.

From A. brunnicolor and A. papua which also occur in New Guinea, the latter species even sympatrically at Dobodura, A. quadrisetosus differs by its smaller size, the colour of antennae with antennomeres 3-11 not darkened, the shape of the pronotum with sides almost rectilinearly narrowed to the sharp posterior angles, and the smaller and less produced eyes.

It should be remarked that the single specimen from "vic. Hollandia " which DARLINGTON (1968) reported also as A. ustus does not belong to the new species described here. It represents probably an undescribed species close to A. papua DARLINGTON.

D i s t r i b u t i o n A. quadrisetosus nov.sp. is so far known only from Papua New Guinea.

Figures

Figs. 9-11: Acupalpus (Stenolophidius) quadrisetosus nov.sp. Habitus, head and pronotum. (9) Holotype, (10, 11) Paratypes, PNG, Dobodura.

Figs. 12-17: Acupalpus (Stenolophidius) quadrisetosus nov.sp. Median lobe of aedoeagus lateral and dorsal aspect. (12) Holotype; (13-17) Paratypes, Dobodura.