Paradrilus opacus Kiesenwetter, 1865

Kundrata, Robin, Baena, Manuel & Bocak, Ladislav, 2015, Classification of Omalisidae based on molecular data and morphology, with description of Paradrilinae subfam. nov. (Coleoptera: Elateroidea), Zootaxa 3915 (3), pp. 413-422 : 417-419

Paradrilus opacus Kiesenwetter, 1865

( Figs 5 , 8–18 )

Paradrilus opacus Kiesenwetter, 1865: 369 .

Type material. Lectotype [here designated], male, "Andalusia, Kiesenwetter, 326. 33." [invalidly designated as a paratype by a local curator]; Paralectotype [here designated], male, the same data as lectotype (Hungarian Natural History Museum, Budapest).

Other material examined. 2 males, "Andalusien" (Naturhistorisches Museum, Basel), 2 males, "Andalus., Kratz, 64." (Muséum national d'Histoire naturelle, Paris), 1 male, " Spain, Córdoba, Santa María de Trassierra, Arroyo del Molino, 20.–25. v. 2012, M. Baena leg." ( DNA voucher specimen RK0626; Laboratory of Molecular Systematics, UP, Olomouc).

Redescription. Adult, male. Body slender, 2.2–2.7 mm long, 3.7 times longer than width at humeri, weakly dorso-ventrally flattened, parallel-sided ( Fig. 5 ); moderately sclerotized, cuticle of elytra and abdomen soft, flexible; dark brown to black colored, surface mat, finely punctured, with dense, short vestiture.

Head small, hypognathous, slightly narrower than prothorax, exposed from prothorax, with fully developed mouthparts; cranium prolonged anteriorly, with inconspicuous antennal sockets, antennal insertions fronto-lateral, separated by narrow bridge, about 0.6 times width of maximum diameter of antennal cavity. Eyes small, moderately prominent, eye diameter 1.4 times their frontal distance. Antennae filiform, 11-segmented, antennomeres round in cross section ( Fig. 8 ); scape robust, parallel-sided, constricted at base, apex asymmetrical; pedicel slightly triangular, robust, constricted at base, widely rounded apically; antennomere 3 shortest, triangular; antennomere 4 much longer; following antennomeres gradually shortened except terminal one. All antennomeres with moderately dense, erect pubescence. Fronto-clypeal suture absent; anterior edge of clypeus concave; labrum membranous, hypopharynx T-shaped, sclerotized, lateral processes long, suboesophaginal ring absent ( Fig. 12 ). Mandibles slender apically, robust at base, slightly curved; incisor without teeth ( Fig. 9 ). Maxilla with small cardo, stipes well developed, plate-shaped; galea and lacinia fused in setose, mala basally sclerotized; palpifer triangular, robust; maxillary palpi four-segmented, palpomere 1 small, transverse, palpomeres 2 and 3 robust, about as long as wide, apical palpomere twice longer than width at base, slender apically, apex widely rounded ( Fig. 10 ). Labium small, praementum short, wide, reduced to convex plate with extensive palpal cavities, projected and pointed apically, without ligula or apical setae; postmentum fused with gula, sclerotized, plate-like, about as long as width; labial palpi tiny, two-segmented, basal palpomere wide, transverse, apical palpomere slender, almost parallel-sided, weakly pointed at apex ( Fig. 11 ).

Prothorax about as long as width (pronotum length/width ratio=0.9), anterior edge straight, frontal angles obtuse, anterior foramen widely rounded; posterior angles obtuse, posterior margin weakly emarginate in middle; lateral edges widely convex, widest in frontal fourth, straight posteriorly, pronotum narrower basally than elytral humeri, disc convex, lateral margins bent downwards, with inconspicuous pleura anteriorly, disc without any carinae or keel, mat, finely structured, with punctures at frontal and posterior corners ( Fig. 13 ). Prosternum moderately long, with wide parallel-sided prosternal process bearing divergent short and robust branches at apex ( Fig. 14 ). Scutellum bilobate. Mesoventrite wide, coxae in extensive cavities laterally. Metasternum long, pleural part connected to metasternum with membrane, epimeron and episternum slender. Elytra very slender, tapering to apex, with humeral edge and pleura present in basal third, posterior half of elytra flat, elytra without longitudinal costae, surface with fine papillae bearing apical setae; elytral apexes separately rounded ( Fig. 5 ). Wing as in Fig. 15 . Legs slender, compressed ( Fig. 16 ); coxae separated, elongate; trochanters slender, moderately long, transversally cut at apex; femora moderately robust; tibiae slender, with pair of small spurs apically; tarsi with five slender tarsomeres, tarsomeres 1–3 subequal, tarsomere 4 short, tarsomere 5 slender, long; pulvilli absent; claws simple ( Fig. 16 ).

Abdomen with eight visible ventrites, basal ventrite membranous in middle part, terminal male segments as in Fig. 17 . Aedeagus of trilobate type, with long parameres; apices of parameres simple, partly membranous; internal sac inconspicuous, membranous; phallobase plate-like, v-shaped, with strengthened lateral margins and posterolateral processes ( Fig. 18 ).

Measurements (lectotype). Body length 2.70 mm, width at humeri 0.73 mm, pronotum length 0.50 mm; pronotum width 0.57 mm, minimum frontal distance between eyes 0.30 mm, maximum eye diameter in lateral view 0.21 mm.

Distribution. Southern Spain (Andalusia: Córdoba, Huelva, Jaén, and Sevilla provinces; Kiesenwetter 1866, Bahillo de la Puebla & López Colón 2005).

Biology and ecology. The specimens were collected by sweeping of the herbal stratum in a forested place near Santa María de Trassierra, Córdoba, Spain ( Fig. 19 ).

Remarks. The female and larva are unknown. As only males are present in all examined collections, we suppose that the females of Paradrilus do not complete metamorphosis similarly to other Omalisidae ( Kiesenwetter 1866, Bocak & Brlik 2008).

The type material is not present in the Kiesenwetter collection in Zoologische Staatssammlung München, Germany (K. Neven, personal communication) and might be distributed in several museums. We were able to locate types only in the Budapest museum and several conspecific individuals elsewhere. The specimens in the Budapest collection were designated by a curator as paratypes, but there is no indication in the original description that holotype and paratypes were designated and all types must be considered as syntypes ( ICZN 1999). We prefer to designate lectotype as the beetles with limited dispersal propensity tend to produce separate, evolutionary isolated populations in a limited geographical space ( Malohlava & Bocak 2010) and the original series can include several species. The here fixed morphological concept of Paradrilus follows that represented by identified specimens in several European collections.

Figures

FIGURE 19. Habitat of Paradrilus opacus Kiesenwetter, 1865 — Arroyo del Molino, Santa María de Trassierra, Córdoba, Spain.

FIGURES 1 – 7. 1 — The maximum likelihood (ML) Elateroidea phylogenetic tree of 557 taxa aligned by BlastAlign and inferred from RAxML; 2 — Omalisidae phylogeny inferred from RAxML. The values at branches represent bootstrap values inferred from ML analyses of datasets aligned by BlastAlign and Mafft, respectively. 3 — Euanoma marketae Kundrata & Bocak, 2007 (holotype); 4 — Pseudeuanoma sp.; 5 — Paradrilus opacus Kiesenwetter, 1865 (lectotype); 6 — Phaeopterus unicolor Costa, 1857 (holotype); 7 — Omalisus fontisbellaquei Geoffroy, 1762. Scale 2 mm (Figs 3 – 7).

FIGURES 8 – 18. Paradrilus opacus Kiesenwetter, 1865; 8 — antenna; 9 — mandible; 10 — maxilla; 11 — labium; 12 — hypopharynx; 13 — pronotum; 14 — prosternum; 15 — wing; 16 — leg; 17 — last abdominal segments; 18 — aedeagus. Scale 0.05 mm (Fig. 11), 0.1 mm (Figs 9 – 10, 12, 17 – 18), 0.2 mm (Figs 13 – 14, 16), 0.5 mm (Figs 8, 15).