Ceratogeusis Ferreira, 2025

Ferreira, Vinicius S., 2025, Description of Ceratogeusis thamiresae new genus and species from Panama, the first Telegeusinae (Coleoptera, Elateroidea, Omethidae) with flabellate antennae, Contributions to Entomology 75 (1), pp. 223-228 : 223-228

Ceratogeusis Ferreira gen. nov.

Figs 1 , 2

Etymology.

Ceratogeusis gen. nov. is a combination of the word Cerato, which comes from the Greek kéras (κέρας), in allusion to the developed antennae of the new taxon, and a combination with the radical geusis, from the Telegeusinae type genus Telegeusis , which is derived from ancient Greek: Tele (ancient Greek: τῆλε, tēle) meaning elongate, and geusis (ancient Greek: γεῦσις), a word which is associated with the sense of taste, probably in reference to the elongate maxillary palps.

Type species.

Ceratogeusis thamiresae gen. nov. et sp. nov.

Diagnosis.

Ceratogeusis gen. nov. can be immediately separated from all known Telegeusinae by its distinctly flabellate antennae from antennomeres 5–10 (Figs 1 , 2 A ) (vs. antennae filiform in Telegeusis , Platydrilus , Pseudokarumia and Stenodrilus , and serrate to subserrate in Pseudotelegeusis ), the presence of one tentorial pit (shared with some Pseudotelegeusis , Stenodrilus and Platydrilus vs. two pits in Telegeusis and some Pseudotelegeusis ), the labial palp 1 - segmented (vs. variable, 2–3 segmented in Telegeusis , 2 - segmented in Stenodrilus and Platydrilus , 1–2 - segmented in Pseudokarumia ; 1 - segmented shared with Pseudotelegeusis ), the maxillary palp 4 - segmented (vs. 3 - segmented in Stenodrilus and Platydrilus ; shared 4 - segmented palp in Telegeusis and Pseudotelegeusis ; apparently 4 - segmented in Pseudokarumia ) and by the tibial spines smooth (vs. serrate in Pseudokarumia , smooth on all other genera).

Description.

Color: Dark brown, legs slightly lighter than remainder of body (Fig. 1 ). Body: Elongate, parallel-sided, dorsoventrally flattened, and covered with sparse, erect setae (Figs 1 , 2 A ), overall integument shiny. Head: Slightly wider than long behind eyes, vertex with a distinctly elevated carina (Figs 1 , 2 A, B ). Antennal tubercles slightly prominent, lateralized. Antennae 11 - segmented, scape, pedicel and antennomere 3 filiform, antennomere 4 expanded apically, distinctly serrate, antennomeres 5–10 flabellate, stems very short, antennomere 11 elongate, as long as branches of antennomeres 5–10 (Fig. 1 ), inserted anteriorly to the eyes on laterad of head. Eyes hemispherical, small, finely faceted, widely separated. Frons wider than long. Frontoclypeal suture complete, distinct. Labrum wider than long, with pronounced median tooth (Fig. 2 B ). Mandibles falciform. Maxillary palpi 4 - segmented, multiple times shorter than antennae; last palpomere digitiform, slightly compressed, ca. 4 × longer than second (Fig. 2 A, B ). Labial palps 1 - segmented. Tentorium with one pit, gula with two sutures (Fig. 2 B ). Thorax: Pronotum subpentagonal, submarginally impressed, with angles round; disc convex, bearing a median longitudinal impression (Fig. 1 ). Scutellar shield rectangular, not notched. Elytra subparallel, slightly dehiscent, apically round and densely rugose, epipleura present on basal third. Prosternum U shaped, wider than long; metaventrite posterior angles round, metadiscrimen complete. Legs: Pro and meso- coxae conical, metacoxae elongate. Trochanters pill-shaped, small. Femora fusiform, flattened. Tibiae elongate, bearing two apical smooth spines. Tarsal formula 5-5 - 5, claws simple. Abdomen: Composed of eight non-fused ventrites. Genitalia: aedeagus trilobate, typical elateriformia (Fig. 2 C ). Median lobe tapered towards apex, apically round; parameres spatulate, ventrally bearing sparsely distributed setae.

Measurements.

Total Length (i. e., exposed portion of head + pronotum + tip of abdomen): 2.5 mm. Width (across humeri): 0.5 mm.

Distribution.

Panama.

Figures

Figure 1. Ceratogeusis thamiresae Ferreira, sp. nov. Dorsal habitus.

Figure 2. Ceratogeusis thamiresae Ferreira, sp. nov. A. Detail of face and antennae; B. Ventral view of head; C. Male genitalia in ventral and dorsal view, respectively.