Bibrax cerroblanco, Tapuy-Avilés & Díaz-Guevara & Caterino, 2025

Tapuy-Avilés, Yarina, Díaz-Guevara, David R. & Caterino, Michael S., 2025, First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species, ZooKeys 1250, pp. 105-133 : 105-133

Bibrax cerroblanco sp. nov.

Figs 2 K, L , 4 E – H

Type material.

Holotype • ♂ ( MECN -EN 38548 ): “ Ecuador: Guayas, -2.159579, -80.02109, Bosque Protector Cerro Blanco , Q. Cusumbo, 25.IV.2022, Winkler, C. Cujigualpa ” / “ Caterino DNA voucher, Ext. MSC-13079, Morphosp. CrBl.A.009 ” / “ MECN -EN 38548 ” . Paratypes (2 ♂, 5 ♀) • same data as type ( MECN -EN 38545 -38547, 38549-38552 ) .

Diagnosis.

BL = 1.89 mm (n = 3). Body with dense, matte-like pubescence; head with single large ommatidium on each side (in both sexes); vertexal foveae shallowly impressed; head rounded posteriorly, prolonged anteriorly into narrowly elongate antennal base; gular teeth well-developed; scape very elongate, weakly curved at base, male antennomere II (pedicel), slightly swollen, ~ 2 × as long as III, evenly widened to apex, antennomeres III – V ~ 1.5 × longer than wide, VI – VIII shorter, VII slightly wider than VI or VIII; IX – XI slightly larger, forming loose, weak club; pronotum elongate, ~ 1.5 × longer than wide, widest just anterior of midpoint, evenly narrowed to base and apex; lateral pronotal foveae deeply impressed, setose, joined by weak transverse sulcus that passes through smaller, nude median fovea, continuing laterad to weakly interrupt lateral margin; shallow longitudinal impressions extend anterad and posterad from lateral and median foveae forming weak sulci; elytra narrow at base (wingless), widening to apex, each with sutural and one lateral dorsobasal foveae, shallow sulci extending posterad from foveae; subhumeral fovea absent; wingless in both sexes; protibiae strongly swollen; male ventrite 5 with broad, shallowly concave, smooth median area, male ventrite 6 with minute median, apical tooth. Aedeagus (Fig. 2 K, L ) with basal bulb large, irregularly subspherical, with prominent basal apodeme; diaphragm located dorsobasally; tegmen dorsoventrally flattened, widened from base as it curves dorsad and distad, apex split ~ 1 / 4 from tip, one side with serrate margin narrowing to acute point, other side slightly longer and ending in slightly expanded, blunt apical plate.

Distribution.

This species is known only from Ecuador’s coastal mountains just northwest of Guayaquil.

Remarks.

This species is among the more convex, less strongly flattened species, having the pronotum gradually narrowed posteriorly, not abruptly constricted behind prominent lateral lobes. Unlike several of these, it does not have male antennomere II expanded, nor does it exhibit modifications of the male metatrochanter. The combination of these, along with a male penultimate metaventrite that is broadly and shallow concave, will distinguish it from any other species currently known. The aedeagus, having a flattened, shallowly bifid tegmen in which the right lobe is marginally denticulate, is highly distinctive.

Etymology.

We name this species for the protected area in which it occurs, El Bosque Protector Cerro Blanco. Semi-surrounded by the greater Guayaquil metropolitan area, this oasis of biodiversity has exceptional conservation value.

Figures

Figure 2. Aedeagus of Bibrax species, lateral view (A, C, E, G, I, K) and dorsal view (B, D, F, H, J, L). A, B. B. chullachaqui sp. nov.; C, D. B. chocoensis sp. nov.; E, F. B. onorei sp. nov.; G, H. B. aratrifer sp. nov.; I, J. B. longiventer sp. nov.; K, L. B. cerroblanco sp. nov.

Figure 4. Habitus of Bibrax species (A, E. Dorsal view; B, F. Lateral view; C. Ventral view; D, H. Male abdominal ventrites; G. Venter of head). A – D. B. longiventer sp. nov.; E – H. B. cerroblanco sp. nov.