Namibdrilus albertalleni, Kundrata & Packova, 2024

Kundrata, Robin & Packova, Gabriela, 2024, Discovery of a new soft-bodied click-beetle genus from Namibia with a unique morphology leads to a modified diagnosis of Drilini (Coleoptera, Elateridae), ZooKeys 1213, pp. 183-197 : 183-197

Namibdrilus albertalleni sp. nov.

Figs 1 , 2 , 3 , 4

Type material.

Holotype • male, “ Namibia, Khomas reg. 140 km SW Windhoek ; 23 ° 14.875 ' S, 16 ° 17.998 ' E; 1382 m; 14. 2. 2023; J. Halada lgt. ” ( NMPC).

Etymology.

This species is named after Albert Allen (Idaho, USA), who allowed us to study the unique specimen in his possession, and who kindly donated it to NMPC. For recent discussions about the need for protecting stable biological nomenclatural systems, which also includes the problematics of eponyms, we refer to Jiménez-Mejías et al. (2024).

Diagnosis.

As for the genus (vide supra).

Description.

Male. Body (Fig. 1 A, B ) slightly convex dorsally, 3.30 times longer than width at humeri (8.30 mm long, 2.50 mm wide); yellowish brown to light brown, with head and most of abdomen slightly darker, light brown to brown, and elytra reddish brown to dark brown; body surface covered with yellow pubescence.

Head (Fig. 2 A – D ) including eyes about 1.15 times as wide as pronotum; surface rather flat, more or less smooth basally, rougher toward apex, punctures sparse and fine but denser and larger basally; frontoclypeal region strongly produced straight forwards between antennae, gradually narrowed toward apex, lateral margins distinctly elevated and thickened above antennal insertions, forming a narrow median furrow, apically again slightly widened, subtruncate, apical margin slightly raised, carinate, very widely rounded. Eyes large, strongly prominent, their minimal frontal separation 1.15 times maximum eye diameter. Labrum covered by frontoclypeal region, visible from frontal view, very short, transverse, with frontal margin slightly concave; sparsely punctate and covered with long semi-erect setae. Mandible unidentate, robust, relatively wide, distinctly curved; base with rough surface covered with long semi-erect setae, apical part shiny. Maxilla with palpus tetramerous, slender, about as long as mandible, palpomere II elongate, palpomere III only slightly longer than wide, terminal palpomere longest, fusiform, apically narrowed, with apex obliquely cut. Labium with palpus trimerous, tiny, less than half length of maxillary palpus, palpomere I short, transverse, terminal palpomere elongate, narrow, fusiform, apically gradually narrowed, obliquely cut. Antenna (Fig. 2 E ) approximately 4.3 mm long, with 11 antennomeres, robust, pectinate from antennomere 3, reaching humeri when oriented backwards; scapus robust, about 1.8 times as long as wide; pedicel minute, shortest, slightly longer than wide; antennomere 3 about twice as long as pedicel, elongate, with ramus about 0.3 times as long as antennomere itself, antennomere 4 elongate, with ramus about as long as antennomere itself, antennomeres 5–10 subequal in length, elongate, with rami about 1.5–1.6 times as long as respective antennomeres, terminal antennomere twice as long as preceding antennomeres, simple, elongate, about 5.5 times as long as wide, apically narrowed, outer side medially shallowly emarginate.

Pronotum (Fig. 3 A, B ) roughly subrectangular, 0.6 times as wide as elytra, widest at posterior angles, 1.30 times as wide as long (1.20 mm long, 1.55 mm wide). Anterior margin somewhat widely rounded, slightly produced medially, sides concave, gradually narrowed from anterior margin toward about three-fourths of pronotum length and then distinctly widened at posterior angles, posterior margin simple, trisinuate, rather arcuately and shallowly emarginate medially. Anterior angles inconspicuous; posterior angles short but distinct, divergent, with rough surface, apically narrowly rounded. Lateral carina not developed. Surface of disc relatively rough, sparsely and finely punctate, with moderately dense, long, semi-erect pubescence. Pronotosternal suture very short. Prosternum (Fig. 3 C ) strongly transverse, its surface uneven, sparsely punctate and covered with semi-erect setae, mainly at frontal margin; prosternal lobe absent, frontal margin almost straight; prosternal process absent. Scutellar shield (Fig. 3 A ) flat, tongue-like, elongate, approximately 1.70 times as long as wide, with anterior margin gradually declivitous, medially slightly produced, apex subtruncate, medially slightly emarginate. Mesoventrite (Fig. 3 C ) small, narrow, v-shaped, with posterior margin simply rounded. Mesocoxal cavity open to both mesepimeron and mesanepisternum. Metaventrite (Fig. 3 D ) large, subtrapezoidal, covered with fine punctures and semi-erect pubescence; discrimen incomplete. Elytra (Figs 1 A , 3 E ) subparallel-sided, only slightly gradually narrowed from humeri to about apical third, both combined 2.30 times as long as wide (5.70 mm long, 2.50 mm wide), 4.75 times as long as pronotum, surface uneven, basally wrinkled, without any distinct striae or lines of punctures, only with several faint costae at basal half, irregularly finely punctate, with long, semi-erect pubescence oriented posteriorly, apices internally slightly divergent, separately rounded; epipleura wider anteriorly, abruptly narrowed near posterior part of metanepisternum, then reduced. Hind wing fully developed. Leg (Figs 1 A, B , 3 A – D, F – H ) moderately long, slightly compressed, with surface covered with moderately long, semi-erect setae, which are thickened mainly ventrally and apically; coxa robust, elongate; trochanter elongate, slightly widened apically, attached obliquely to femur; femur gradually slightly widened towards apex; tibia slightly longer than femur; tarsus (Fig. 3 F – H ) shorter than tibia, metatarsus relatively longer than pro- and mesotarsus; tarsomeres I – III elongate, widened apically, progressively decreasing in length, tarsomere IV short, ventrally with short membranous lobe, terminal tarsomere long, slender; pretarsal claws simple, slender, slightly curved, basally with long setae.

Abdomen (Figs 1 B , 4 A ) soft, highly flexible, with eight free sternites (II – IX) connected with each other by extensive membranes; sternite II semi-membranous, with two lateral sclerites and two median sclerotizations; all ventrites with sparse, shallow punctures, covered with semi-erect pubescence, which is denser and longer posteriorly and mainly at margins; penultimate ventrite (sternite XIII) with two shallow posterolateral and one rounded median emarginations. Tergites IX and X (Fig. 4 C ) wider than long, weakly connected by membrane, both covered with fine punctures and relatively long setae; tergite IX basally with two sublateral processes, tergite X apically widely rounded. Sternite IX (Fig. 4 D ) about 1.5 times as long as wide, roughly oval, with basal portion medially deeply emarginate, apex rounded, surface finely punctate and sparsely covered with setae; sternite X about 0.45 times as long as sternite IX, slightly longer than wide, somewhat rounded. Male genitalia (Fig. 4 B, E – G ) about 2.6 times as long as wide, about 1.3 times as long as sternite IX; median lobe elongate, distinctly longer than paramere, basally moderately curved in lateral view, with two very short basal struts, dorsally without a subapical hook, rather subparallel-sided in dorsoventral view, slightly widened after half, then slightly but abruptly constricted before apex, apically rounded; paramere distinctly longer than phallobase, with basal half robust and wide, and with apical half distinctly narrowed, divergent, apically narrowly rounded in lateral view; phallobase short, about 1.3 times as wide as long, widely u-shaped.

Females and immature stages unknown.

Distribution.

Namibia.

Figures

Figure 1. Namibdrilus albertalleni gen. et sp. nov., holotype, male A habitus, dorsal view B habitus, ventral view. Scale bar: 4.0 mm.

Figure 2. Namibdrilus albertalleni gen. et sp. nov., holotype, male A head with basal antennomeres, dorsal view B head, frontolateral view C head, frontal view D head, ventral view E left antenna, dorsal view. Scale bars: 1.0 mm (A – D); 2.0 mm (E).

Figure 3. Namibdrilus albertalleni gen. et sp. nov., holotype, male A head and prothorax, dorsal view B head and prothorax, lateral view C prothorax and mesothorax, ventral view D metathorax, ventral view E apical portion of elytra, dorsal view F right protarsus, dorsal view G left mesotarsus, dorsal view H left metatarsus, dorsal view. Scale bars: 1.0 mm (A, D); 0.5 mm (B, C, E, F – H).

Figure 4. Namibdrilus albertalleni gen. et sp. nov., holotype, male A abdomen, ventral view B male genitalia (undissected), dorsal view C abdominal tergites IX and X, dorsal view D abdominal sternite IX, ventral view E male genitalia, dorsal view F male genitalia, lateral view G male genitalia, ventral view. Scale bars: 3.0 mm (A); 0.2 mm (B); 0.5 mm (C – G).