Lecanomerus trapezus ( FAUVEL , 1882)

Auvel, 2016, Two new species of the Anthracus annamensis group from Australia and New Caledonia, and notes on identity and generic placement of Acupalpus angulatus MACLEAY, 1871 and Acupalpus trapezus FAUVEL, 1882 (Coleoptera, Carabidae, Harpalini, Stenolophina, Pelmatellina), Linzer biologische Beiträge 48 (2), pp. 1295-1312 : 1302-1303

Lecanomerus trapezus ( FAUVEL, 1882) ( Figs 18-24 )

Stenolophus trapezus FAUVEL, 1882: 272 (Type locality: Nouvelle Calédonie: Koné.)

Acupalpus trapezus FAUVEL : FAUVEL 1903: 227 [fauna]

Acupalpus (Acupalpus) trapezus FAUVEL : CSIKI 1932: 1254 [world catalogue], LORENZ 1998: 338, 2005: 360 [world catalogues]

T y p e m a t e r i a l: Holotype: 6 ( IRSNB) labelled " Coll. R. I. Sc. N. B. / Nouvelle Calédonie / Koné rec Deplanche / ex. Coll. Fauvel " [large pale reddish label, with "Koné" on a white label, glued on the large label], "Coll. et det. A. Fauvel / Acupalpus / trapezus Fvl. " [last two lines hw Fauvel]; "TYPE" [red label with black border] and " Lecanomerus / trapezus / ( Fauvel, 1882) / det. B. Jaeger 2016". The holotype is in good condition without missing body parts.

A d d i t i o n a l m a t e r i a l: 266, 2 ♀♀ (Coll. Fauvel, IRSNB) from "Nouvelle Calédonie" identified as Acupalpus trapezus by Fauvel. One of the females with reduced yellowish colouration on apical part of elytral intervals bears the two handwritten labels of Fauvel: " trapezus Fvl. var.?" and "Elytres apice aliter coloratis".

A third male of " Acupalpus trapezus " from "Païta" deposited in the coll. Fauvel, does not belong to L. trapezus but to a new species of the Anthracus annamensis group which is described earlier in this paper.

R e d e s c r i p t i o n: General appearance as figured ( Fig. 18 ). Body length 4.1- 5.0 mm (HT 4.3); width 1.6-2.0 mm.

Shiny. Head blackish brown with labrum and mandibles (inner margin and apex darker) reddish, palpi pale yellowish brown. Pronotum dark brown with lateral margins, base and sometimes also apex paler reddish brown. Elytra dark brown or blackish brown, with first, seventh and eights interval and apex yellowish. Usually also the apical parts of interval 2, 3, 4 and 6 yellowish. Antennae yellowish or pale reddish brown, sometimes antennomeres 1-4 partly infuscated. Ventral surface mainly blackish or dark reddish brown, but epipleura of pronotum weakly and those of elytra moderately paler reddish brown, and ventrites laterally with a yellowish patch at sides.

Head ( Fig. 18-20 ) moderately large, including eyes 0.72-0.74 times as wide as pronotum, with eyes moderately prominent (head 1.54-1.64 times as wide as head between eyes). Clypeal suture only very weakly impressed, clypeo-ocular prolongations deeply impressed reaching supraorbital ridge. Mandibles rather long and sharp at apices. Labrum rather long, with apex weakly emarginated. Antennomere 1 smooth, except for usual seta, 2 with few setae apically, and antennomeres 3-11 densely pubescent. Microsculpture on labrum, clypeus, frons and vertex distinct, consisting of isodiametric meshes.

Pronotum ( Fig. 18-20 ), 1.23-1.27 times as wide as long, 1.35-1.38 times as wide as head. Lateral seta inserted just at, or just anterior to beginning of second quarter. Apical margin moderately concave, with anterior angles weakly projecting forward (characters not well seen in figures) and rather narrowly rounded at apices. Sides weakly convex in anterior two thirds, rectilinearly narrowed at posterior third with a short sinuation in front of hind angles, which are distinct with apices slightly projecting laterad. Basal margin rectilinear medially, and weakly oblique to posterior angles. Lateral channels very thin, evenly narrow from anterior to posterior angles. Lateral bead very fine, becoming more distinct in front of hind angles, prolonged around hind angles reaching medial third of base. Baso-lateral impressions very flat and indistinct, weakly delimited from the moderately convex pronotal disc and the slightly depressed medial part of base. Basal impressions and other surface of pronotum impunctate. Median line fine, disappearing before reaching basal and apical margins. Anterior transverse impression weak to moderate. Microsculpture distinct consisting of weakly transverse meshes on disc and at sides, and of isodiametric meshes at medial portion in front of apical margin, at medial part of base and at baso-lateral impressions.

Elytra ( Fig. 18 ) weakly convex, with sides weakly to moderately widened posteriorly, widest about at middle, 1.50-1.55 times as long as wide, 2.67-2.86 times as long and 1.44-1.48 times as wide as pronotum. Elytral striae weakly impressed and impunctate, scutellar striole lacking. Intervals rather flat from base to apex, becoming weakly narrowed in front of the latter. Basal pore at beginning of second stria present, interval 3 in third quarter with one setiferous pore, adjoining stria 2. Microsculpture on scutellum isodiametric, on elytral intervals distinct, consisting of weakly to moderately transverse meshes. Macropterous.

Ventral side: Penultimate segment of labial palpi bisetose, ligula bisetose, mentum with a distinct medial dent, mentum and submentum divided by a distinct suture. Prosternum, with two or three larger punctures, proepisterna and prosternal process, meso- and metasternum, mes- and metepisterna impunctate, without setae. Metepisterna at inner margin about 1.6 times longer than wide at basal margin. Ventrites smooth, without pubescence, but with the usual pair of ambulatory setae, and last visible ventrite of the males with two and that of females with four setae at apical margin.

Pro- and mesotarsomeres 1-4 markedly (the former) or moderately dilated (the latter), protarsomeres 1-4 and mesotarsomeres 2-4 with spongious vestiture on ventral surface.

Median lobe of aedeagus ( Figs 21-24 ) with general appearance as figured. Apex with characteristic shape in lateral ( Fig 21a ) and dorsal aspect ( Fig 24 ). Internal sac without larger apical teeth or sclerites but with characteristic fine structures (fig. 24).

R e m a r k s FAUVEL (1882: 272) described the species from one specimen from Koné, New Caledonia, collected by Deplanche, and placed it in the genus Stenolophus DEJEAN , including Amphibia MONTROUSIER (now a junior synonym of Stenolophus subgenus Egadroma). According to Fauvel’s "Obs." and his key of New Caledonian Stenolophus (species, which partly belong to the genus Stenolophus and partly to genus Lecanomerus ), S. trapezus differs from other members of the genus by its small size, its cordate, non-transverse pronotum, and metatarsomeres not carinate at outer margin. Later, in his "Fauna Analytique des coléoptères de la Nouvelle-Calédonie " FAUVEL (1903: 227) listed the species as a member of the genus Acupalpus and quoted "Deux exemplaires". In subsequent catalogues ( CSIKI 1932: 1254, LORENZ 1998: 338, 2005: 360) S. trapezus was also listed as a member of the genus Acupalpus . Because FAUVEL’ s original description did not include characters which allow verification of the generic assingement of S. trapezus , its placement within the genus Acupalpus has remained doubtful. The recent examination of the holotype and additional specimens revealed that the species displays the diagnostic characters, including the spongious ventral surface of pro- and mesotarsomeres of males, of the genus Lecanomerus of the Harpalini subtribe Pelmatellina and is therefore transferred to this genus.

Figures

Figs 18-20: Lecanomerus trapezus (FAUVEL, 1882). Habitus, head and pronotum. (18) Holotype; (19, 20) "Nouvelle Calédonie".

Figs 21-24: Lecanomerus trapezus (FAUVEL, 1882). Median lobe of aedoeagus, lateral and dorsal aspect. (23) Holotype; (21, 21a, 22, 24) "Nouvelle Calédonie".