Speotarus opacipennis, Baehr, 2020

Speotarus opacipennis View in CoL , sp. nov.

Figs 3 View Figs 1-3 , 5

Type material. Holotype: ♁, “Fowlers Gap, NW.NSW G.Campbell 1976 / Speotarus sp. n. det. B. P. Moore 1999” ( AMS K 255284 ) . – Paratype: ♀, “ AUSTRALIA, NT Areyonga 1 December 1980 Joe Sedlacek / AMS K 241130 ” ( CBM) .

Etymology. The name refers to the opaque surface of the elytra.

Diagnosis. Characterized by the strikingly opaque surface of the elytra that is produced by very distinct, isodiametric microreticulation; further distinguished from S. lucifugus Moore, 1964 by slightly more prominent eye, differently shaped pronotum with basally deeper marginal channel, and sinuate, instead of straight, anterior part of the sclerotized rod in the internal sac of the aedeagus.

Description

Measurements. Length: 9.1-9.8 mm; width: 3.5- 3.7 mm. Ratios. Width/length of pronotum: 0.96- 0.98; width base/apex of pronotum:1.01-1.02; width pronotum/head: 1.04-1.08; length/width of elytra: 1.65-1.66; length orbit/eye: 1.40-1.45.

Colour ( Fig. 3 View Figs 1-3 ). Upper surface, including labrum, mandibles, palpi, and legs uniformly, more or less pale reddish-brown, but head darker than pronotum and elytra; lateral margin of pronotum slightly paler than disk; apices of palpi slightly paler than the rest; antenna very slightly paler than the body; lower surface more or less dark rufous.

Head ( Fig. 3 View Figs 1-3 ). Narrow and elongate, little narrower than prothorax. Neck rather wide, dorsally with a slight transverse impression. Eye moderately large, but laterally little protruded, orbit obliquely convex, slightly longer than the eye. Laterally of eye with a more or less distinct sulcus; frons in anterior part with some irregular longitudinal strioles, that are less distinct in the paratype. Clypeal suture distinct. Labrum rectangular, apex straight. Mandible moderately elongate, straight. Antenna rather slender and elongate, just attaining base of pronotum, median antennomeres c. 2.7 × as long as wide. Both palpi slender and elongate, basal palpomere of maxillary palpus thickened. Maxillary palpus almost impilose, labial palpus with moderately sparse but distinct pilosity. Mentum with an elongate, unidentate tooth. Median gular setae very elongate. Both supraocular setae present, the posterior one slightly removed from the eye. Microreticulation superficial, composed of about isodiametric meshes, punctures sparse, surface glossy.

Prothorax ( Fig. 3 View Figs 1-3 ). Narrow, gently cordate, widest in apical third, in the posterior two thirds oblique, near base slightly concave. Disk gently convex; lateral margin raised, with a fairly deep sulcus that is distinctly widened towards base. Apex straight, anterior angle barely projecting, obtuse.Base in middle slightly convex, laterally oblique, basal angle c. 100°, but quite obtuse. Both, anterior and posterior transverse sulci shallow. Median line almost complete, rather deep.Apex only laterally very inconspicuously bordered, base coarsely bordered. Anterior marginal seta located at apical third, at the widest diameter, posterior seta situated slightly in front of the basal angle, both setae elongate. Disk apparently impunctate, with several fine, irregular, transverse strioles. Microreticulation fine though rather distinct, composed of slightly transverse meshes. Surface moderately dull.

Elytra ( Fig.3 View Figs 1-3 ). Comparatively narrow and elongate, slightly widened apicad, lateral margin in middle straight but slightly oblique. Dorsal surface rather depressed. Humerus widely rounded, apex unarmed, slightly oblique and gently convex, not incurved at suture. Striae complete, well impressed, at bottom very finely punctate-crenulate; intervals well raised, even slightly tectiform. Two discal punctures and setae present; the anterior one located at the basal two fifth and in middle of the 3 rd interval, the posterior one located far behind, about at the apical eighth and attached to the 2 nd stria. 12 marginal setae present, consisting of a humeral group of 6 setae, a median group of two, and a subapical and an apical group of two setae each. Also one preapical seta at the end of the 2 nd stria present. Intervals impunctate. Microreticulation isodiametric, fine though very distinct, making the surface strikingly opaque.

Metathoracic wings. Fully developed.

Lower surface. Prosternal process short, posteriorly slightly convex, bordered. Proepisternum and mesepisternum impunctate. Metepisternum elongate,> 2 × as long as wide at anterior border, impunctate. Whole lower surface with fine and rather superficial, isodiametric microreticualtion, glossy. Male sternum VII bisetose, female sternum VII quadrisetose.

Legs. Elongate and very slender. Tibiae in apical half of the inner side rather densely pilose. Tarsomeres not sulcate. 4 th tarsomeres not excised. 5 th tarsomeres setose beneath. 1 st- 3 rd tarsomeres of male protarus and mesotarsus densely biseriately squamose.

Male genitalia ( Fig. 5). Genital ring moderately wide, triangular, apex slightly asymmetric. Aedeagus rather stout, symmetric, lower surface, apart from basal part, almost straight, towards apex slightly directed down. Apex moderately elongate, triangular, obtuse at tip. Orificium short, situated mainly on the left side. Internal sac with an elongate, sclerotized rod that is incurved in the posterior part, and sinuate in the anterior part; also with some little sclerotized folds. Both parameres rather elongate, at apex obtusely rounded.

Female gonocoxites. Unknown, because the female is not well preserved.

Variation. Some variation noted in relative width of pronotum and in shape of elytra, which are shorter and wider in the female.

Distribution. Extreme western New South Wales and southern central Northern Territory.

Collecting circumstances. Not recorded.