Cordielytrum obscurum, Whorrall & Philips, 2021

Whorrall, Kyle & Philips, Keith, 2021, Six new species of spider beetles (Coleoptera: Ptinidae) in the genus Cordielytrum Philips, Zootaxa 5040 (3), pp. 414-427 : 421-422

Cordielytrum obscurum , sp. n.

( Fig. 6 )

Holotype: Peru: Arequipa Reg , 16 km NW Matarani, 18–21.VI.2019 S16.8754° W72.1968°, 285 m dune veg, dung pitfalls K.A.Whorrall & T. K. Philips . Holotype has been deposited in MUSM . Paratypes (24): Same data as holotype. Paratypes have been deposited in MUSM, KAWC, TKPC , and JBHC.

Diagnosis: This species is distinguished from most congeners by its relatively slender shape, the more rounded shape of its pronotum, the rough, disheveled appearance of its vestiture, and the tassel-like shape of some setae. It can be distinguished from C. fimbriatum ( Fig. 5 ) by the longer and more filiform setae of the elytral humeral angles, narrower and more sparsely spaced scales of the elytra, and darker coloration.

Description. Body small, ovate, convex; mottled dark brown. Length (anterior of pronotum to apex of elytra) 2.16–2.35 mm.

Head completely covered with depressed, light tan, ovoid scales; pronounced superantennal carinae; antennae stout, antennomeres densely covered in scales, setae increasingly fine toward apex, antennomeres 1–4 and 11 longer than wide, others subequal; clypeus distinct; labrum with short erect orange setae apically; frons with elongate ligulate scales pointing toward middle, especially prominent toward apex.

Pronotum covered with densely matted setae, relatively few short, erect setae protruding from deep cavities within matted setation; anteriorly depressed, especially laterally, with distinct frontal ridge; medial cavity very deep, extending over half total length of pronotum, border well-defined except at middle anterior and posterior; two posterolateral cavities on each side deep and distinct.

Elytra: Setation mottled tan with darker brown patches, background color dark brown; surface sparsely covered in slender scoop-shaped setae, gaps between setae showing bare elytra; basal 1/3 of anterolateral margin with row of long setae, setae mostly simple, but some variably tassel-like; five low longitudinal carinae extending length of each elytron, including one at suture, each carina with one row of short tassel-like setae with highly branched apices.

Ventral Surface: Ventral part of pro-, meso, and, metathorax, legs, and abdominal ventrites with scales similar to elytra.

Etymology: The name “obscurum” is from the Latin word for dark, referring to the coloration of this species. Secondarily, this name alludes to the difficulty of separating this species from others closely related.

Figures

FIGURE 5. Cordielytrum fimbriatum. A Dorsal habitus, B ventral sclerites, C lateral view, D frontal close-up. Scale bars: 1.0 mm (A, C), 0.5 mm (B, D).

FIGURE 6. Cordielytrum obscurum. A Dorsal habitus, B ventral sclerites, C lateral view, D frontal close-up. Scale bars: 1.0 mm (A, C), 0.5 mm (B, D).