Pseudobrachyhammus, Vitali, 2022

Vitali, Francesco, 2022, A new endemic flat-faced longhorn from Sulawesi (Coleoptera Cerambycidae), Baltic Journal of Coleopterology 22 (1), pp. 145-148 : 145-148

Pseudobrachyhammus n. gen.

( Figs. 1–3 )

Differential diagnosis. Pseudobrachyhammus n. gen. is characterised inside Lamiini (Breuning,

Vitali F.

1943) by the following combination of characters: claws divergent (“divariqués” according to Breuning), mesotibiae distinctly furrowed, frons not trapezoidal, apex of scape with open cicatrix and obtusely toothed at both angles, pronotum with a strong lateral spine, antennae with some recumbent setae but not evidently fringed, antennomere III as long as scape or as IV, elytra without humeral spine and with flat lustrous granules at base, procoxal cavities posteriorly closed, prosternum and mesosternum regularly rounded.

Though the habitus of Pseudobrachyhammus n.gen. reminds of local genera such as Nemophas Thomson, 1864 or Dolichoprosopus Ritsema, 1881 , the particular proportion of basal antennomeres makes it amazingly similar to the Tropical African genera Brachyhammus Kolbe, 1900 ; Docohammus Aurivillius, 1908 ; Bixadus Pascoe, 1868 ; Parabixadus Breuning, 1935 and Pseudobixadus Breuning, 1979 .

The peculiar shape of the scape separates Pseudobrachyhammus n. gen. from all quoted genera. The most similar genus seems to be the Ethiopian Brachyhammus , the only one to be characterised by lustrous granules on the elytral base and by a singularly similar coloration ( Adlbauer & Beck, 2015). In this genus, however, the antennae are much shorter (surpassing the elytral apex with two articles in male, shorter than body in female), the cicatrix of scape is closed and the claws are opposite.

Nemophas and Dolichoprosopus differ from Pseudobrachyhammus n. gen. in the usual shape of the scape, the longer antennomere III and the rounded elytral apex. In addition, Nemophas differs in the long male forelegs, the tegmen with a triangular appendix and the bilobate female pygidium, while Dolichoprosopus differs in the closer and less elevated antennal supports, the pronotum without V­shaped furrow and the elytra without granulation. This last character is however shared by the Japanese Dolichoprosopus yokoyamai (Gressitt, 1937) , whose taxonomic position should be verified.

The new genus also reminds some local Batocerini, e.g., Abatocera irregularis Snellen van Vollenhoven 1871 , Apriona punctatissima (Kaup, 1866) , Apriona jakli Jiroux 2011 , which differ in posteriorly open procoxal cavities (tribal characters), elytra with humeral tooth, different scape and antennal proportions, etc.

Description. Body lustrous black, covered with fulvous pubescence, almost uniform on head, pronotum, antennae, legs and ventral side but forming large and small irregular spots on the elytra.

Head finely and sparsely punctate, dull; labrum twice as long as wide, densely covered with golden pubescence along the anterior margin, surface without elevated setae; clypeus smooth, ochreous; eyes finely faceted, lower lobes as long as genae; antennal supports strongly elevated, forming a right angle between them; frons and occiput finely furrowed along the middle. Antennae robust, nearly twice as long as body, surpassing the elytral apex with four articles () or slightly longer than body, surpassing the elytral apex with two articles (); scape elongated, parallel­sided, apically transversally truncated, suddenly enlarged and projecting posteriorly at both angles, surface irregularly wrinkled and with incomplete cicatrix; pedicel transverse; antennomere III with some short semirecumbent setae at the inferior side; antennomeres III– X subequal; antennomere XI 1.8 times as long as previous () or hardly longer than previous ().

Pronotum feebly elongated, weakly convex at apex, bisinuate at base, with a strong V­shaped furrow at apex and two transverse furrows at base; each side armed with a strong conical spine feebly recurved posteriorly and bearing some long erect setae on the posterior margin; disc uneven, quite wrinkled, finely furrowed along the middle, with three flat bulges, the central one divided by the furrow, and some punctures at both margins, those after the middle are areolate.

Scutellum trapezoidal, feebly transverse, uniformly covered with recumbent fulvous pubescence, except for a short longitudinal line at the anterior margin.

Elytra elongated (each one about 4 times as long as wide), feebly tapered posteriorly, sub­truncate at apex, without humeral or apical spine, dorsally

Vitali F.

convex, and covered with strong irregular sparse punctures as well as irregular flat lustrous granules at base.

Legs relatively short, without sexual dimorphism; femora fusiform; protibiae slightly bisinuate; mesotibiae obliquely furrowed, without median tooth; metatibiae with two short black spurs at apex; claws divergent.

Prosternum arcuate, with an obtuse ridge along the middle; procoxal cavities posteriorly closed; mesosternum largely rounded anteriorly, with a feeble bulge between the mesocoxal cavities; visible urosternite I as long as II and III together; urosternites II–IV progressively shortened; urosternite V twice () or 3 times () as long as previous, apically concave in both sexes; pygidium truncate.

Median lobe (penis) 6 mm long, dark brown, curved, slightly restricted from base to apex, truncate at apex, 1.7 times as long as the median struts. Tegmen 9 mm long, dark brown; ringed part twice as long as root, laterally constricted, posteriorly converging and united for about one­fourth of its length; parameres fused together but separated by a longitudinal furrow, without appendix, dorsally convex, apically tapered, densely covered with yellow setae from the apical third.

Type species. Pseudobrachyhammus sulawensis n. sp. (monotypic).

Etymology. The genus epithet is a compound name that stems from the Greek prefix Pseudo ­ i.e., “false” and the genus name Brachyhammus , for indicating the similarity between these two genera. Gender masculine.

Figures

Fig. 1. Pseudobrachyhammus sulawensis n. sp., Holotype, (FVC).

Fig. 2. Pseudobrachyhammus sulawensis n. sp., Paratype, (FVC).

Fig. 3. Pseudobrachyhammus sulawensis n. sp. Tegmen and aedeagus in dorsal and lateral view.