Lecanomerus angulatus ( MACLEAY , 1871) Auvel, 2016

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 : 1300-1302

Lecanomerus angulatus ( MACLEAY, 1871) , comb. nov. ( Figs 15-17 )

Acupalpus angulatus MACLEAY, 1871: 104 (type locality: Australia: Gayndah)

Acupalpus angulatus MACLEAY : MASTERS 1885: 421 [catalogue]

Acupalpus (Acupalpus) angulatus MACLEAY : CSIKI (1932: 1243) [catalogue]; LORENZ 1998: 337, 2005: 359 [catalogues]

T y p e m a t e r i a l: Syntype: 1♀ (AMS) with original labels as figured (fig. 15) and " Lecanomerus / angulatus / ( MacLeay, 1871) / det. B. Jaeger 2016". In addition to the attached labels there is a handwritten notice (in the collection obviously arranged close to the specimen) "No Acupalpus / a Lecanomerus /id. M. Baehr '07".

R e m a r k s: Although the specimen bears a label " Holotype " [a subsequent label, obviously attached by museum staff] it should be regarded a syntype because in the original description MacLeay neither designated a holotype nor stated that he studied only one specimen. The syntype has the left antennomeres 4-11 and the right antennomeres 2-11 missing but is otherwise in good condition.

R e d e s c r i p t i o n: General appearance as figured ( Fig. 16 ). Body length 4.9 mm; width 2.2 mm.

Shiny, pronotum and elytra weakly iridescent. Head and pronotum mainly blackish brown, with labrum and mandibles (apex and inner margin darkened) paler and clypeus, posterior part of head, lateral margins and medial part of base darker reddish brown. Elytra paler than pronotum, mainly dark brown with first elytral interval paler reddish brown. Legs and antennae, at least the first three antennomeres (others missing) yellowish to pale reddish brown. Ventral surface blackish to dark reddish brown, with mouthparts and epipleura paler.

Head ( Fig. 17 ) very small relative to pronotum, including eyes 0.62 times as wide as pronotum, with eyes moderately prominent (head 1.54 times as wide as head between eyes). Clypeal suture moderately, clypeo-ocular prolongations deeply impressed reaching supraorbital ridge. Mandibles rather long and sharp at apices. Labrum rather long, with apex weakly emarginated. Antennomeres 1 and 2 with few setae apically, antennomere 3 moderately pubescent. Microsculpture on labrum, clypeus, frons and vertex distinct, consisting of isodiametric meshes.

Pronotum ( Fig. 17 ) 1.32 times as wide as long, 1.62 times as wide as head, widest in second quarter, lateral seta inserted just posterior to beginning of second quarter. Apical margin markedly concave (character not well seen in figures), with anterior angles rather widely rounded and moderately projecting forward. Sides convex in anterior half, rectilinearly narrowed to posterior angles, which are distinct and moderately sharp. Basal margin weakly convex medially, and very weakly oblique to posterior angles. Lateral channels rather evenly narrow in apical half, becoming gradually widened posterior to middle and markedly widened in posterior third, where they are fused with the basolateral impressions. Baso-lateral impressions medium sized, clearly delimited from the markedly convex pronotal disc and somewhat depressed median part of base, flattened to 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 suggested. Microsculpture distinct consisting of strongly transverse meshes on disc and at sides, and of weakly transverse to isodiametric meshes at medial portion in front of apical margin, at medial part of base and at baso-lateral impressions.

Elytra ( Fig. 16 ) strongly convex and rather short with sides moderately widened posteriorly, widest about at middle, 1.40 times as long as wide, 2.68 times as long and 1.47 times as wide as pronotum. Elytral striae distinctly impressed and impunctate, scutellar striole lacking. Intervals rather flat, becoming narrowed and weakly convex at apex. 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 very dense, markedly transverse meshes and/or lines. 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, proepisterna and prosternal process, meso- and metasternum, mes- and metepisterna impunctate, without setae. Metepisterna long. Ventrites smooth, without pubescence, but with the usual pair of ambulatory setae, and last visible ventrite of the female type with one additional pair of setae at apical margin.

R e m a r k s: MACLEAY (1871: 104) described Acupalpus angulatus from an unknown number of specimens collected by Masters in Gayndah, a town on the Burnett River, in SE Queensland. The short description includes few characters, such as length, colour, shape of head, pronotum and elytra, used to differentiate the species from the " Acupalpus mastersi " [= junior synonym of Lecanomerus vestigialis (ERICHSON, 1842) ] described by MacLeay on the same page, but no other characters which allow verification of the generic placement of the species. After the description, the species was only listed in catalogues ( MASTERS 1885: 421, CSIKI 1932: 1243, MOORE et al. 1987: 243, LORENZ 1998: 337, 2005: 359) but was not taxonomically revised. Thus, the generic placement of Acupalpus angulatus has remained doubtful.

Study of the syntype reveals that the species neither belongs to the genus Acupalpus nor to the related genus Anthracus . Although most of the important characters of the female type specimen, such as penultimate segment of labial palpi bisetose, ligula bisetose, mentum dentate, mentum and submentum divided by a distinct suture, prosternum and prosternal process without any seta, abdomen without any pubescence, clypeo-ocular prolongations fully developed and scutellar striole lacking, occurs also in some genera of the subtribe Stenolophina , Acupalpus angulatus does obviously not belong to this subtribe. Though the type of arrangement of adhesive hairs of the ventral surface of male pro- and mesotarsomeres remain unknown, other important characters match modern definitions of the genus Lecanomerus of the subtribe Pelmatellina given by DARLINGTON (1968: 45) and LAROCHELLE & LAVRIERE (2005: 60-61). Thus, I follow here M. Baehr (according to his note on the type specimen) and place the species into the genus Lecanomerus . However, further studies, particularly on the arrangement of adhesive on ventral surface pro- and metatarsomeres of male specimens are necessary to confirm this placement.

Figures

Figs 15-17: Lecanomerus angulatus (MACLEAY, 1871). Original labels, Habitus, head and pronotum. (15-17) Syntype.