Paxillus chapadensis Mattos & Mermudes

Mattos, Ingrid & Mermudes, José Ricardo M., 2013, Synopsis of Paxillus MacLeay, 1819 (Coleoptera: Passalidae): distributional records and descriptions of four new species from Brazil, Zootaxa 3652 (3), pp. 327-342 : 337

Paxillus chapadensis Mattos & Mermudes , new species

( Figs. 22–27 )

Description. Length 16–19 mm. Head ( Fig. 22 ): labrum with anterior margin slightly concave, with fine setiferous punctures; anterior frontal area moderately to densely punctate, shallow, wide, and opaque, interstices unevenly narrowed; anterior margin of frontal area straight; median frontal area with weak elevation anterior to central tubercle; anterior and posterior frontal ridges elevated, evident, extending from central to medial frontal tubercles. Medial frontal tubercles elevated, robust, surpassing anterior margin of frontal area. Inner tubercles distinct, elevated, smaller than medial frontal tubercles; central tubercle short, not free, dilated at base, continuous with posterior lateral tubercles; these evident. Lateral post-frontal area usually punctate; bridge strong and smooth. Supraocular margin with tubercles and very fine punctures; canthus rounded at apex, ocular keel with fine and sparse punctures. Postocular sulcus strong and densely punctuate; punctures confluent, deep, and opaque. Antennae ( Figs. 23–24 ): first antennomere of club short, second antennomere longer; scape with dorsal subapical spine and ventrally impressed with sparse setae. Lateral lobes of mentum somewhat pubescent and with few coarse punctures; scars irregular and open to outside, internally opaque (fossae of each lobe irregularly rounded, deeper and with the margin elevated and clearly marked on the inner portion). Pronotum: anterior margin sinuate; anterior marginal groove narrow and punctate, reaching middle of anterior margin, usually touching margin. Lateral marginal groove narrow and punctate, with fine, sparse pubescence. Sides of pronotum with irregular punctures, which are often fused; with punctate scar; posterior margin with or without short pubescence, or with yellowishorange tuft of setae. Prosternal process strongly impressed and opaque in middle; with shallow, irregular, confluent punctures; laterally smooth and shiny. Scutellum with median circular depression. Elytra with tuft of moderately long and dense setae, dorsal striae with small punctures; lateral striae with large punctures. Mesosternum smooth, with scar usually elongate (rarely oval), narrow and shallow deep; lateral anterior area punctate. Metasternum: disc evident by edges of margin; anterior lateral area punctate and pubescent; posterior lateral area moderately finely punctate, punctures contiguous with margin of disc. Lateral fossae of metasternum narrowing anteriorly with lower margin elevated and in posterior region slightly wider, lacking elevated margin, surface opaque. Sternite 7 rounded or slightly sinuate at apex. Mesotibia dorsally pubescent; with 1 lateral median spine. Aedeagus ( Figs. 25–27 ) as long as wide. Phallus subglobular, longer than parameres and phallobase together (lateral view). Phallobase and parameres fused, lacking suture line. Parameres weakly elongate, conspicuously curved and acuminate at apex, with a distinct downward curve (lateral view).

Dimensions (mm). Total length (from anterior margin of labrum to apex of elytra) 16–19; elytral length (median line) 10–11; pronotal length (median line) 4–5; pronotal width 6; humeral width 5.

Variability. Frontal area with shallow punctures, these varying from contiguous to aligned in two or three irregular rows. In one of the paratypes, the scape of antennae has a spine on only the right side.

Remarks. P. chapadensis is distinguished from other species of the genus by the scape with a dorsal subapical spine and a ventral impression ( Figs. 23–24 ), with sparse setae; and the prosternal process strongly impressed and opaque in the middle. The parameres ( Fig. 26 ) are conspicuously curved and acuminate at the apex in lateral view.

Type material. Holotype male from Brazil: Mato Grosso, Chapada dos Guimarães, 27.XI.1983, Exp. Dep. Zool. UFPR leg., Mattos & Mermudes det. 2012 (DZUP). Paratypes: 3 (1 male, 2 females), 27.XI.1983, 1 female, 18.XI.1983, Exp. Dep. Zool. UFPR leg. (DZUP).

Etymology. The species is named after the type locality, the Chapada dos Guimarães.

Figures

FIGURES 22 – 27. Paxillus chapadensis, male: 22, head and anterior margin of pronotum, dorsal. 23 – 24, antennae: 23, dorsal; 24, ventral. 25 – 27, Aedeagus: 25, dorsal; 26, lateral; 27, ventral. Scale bars = 0.5 mm (Figs. 25 – 27 to the same scale); DS = dorsal spine, VI = ventral impression.