Published January 8, 2026 | Version v1
Taxonomic treatment Open

Metopiellus chasqui Tapuy-Avilés, Díaz-Guevara & Caterino, 2026, sp. nov.

  • 1. Pontificia Universidad Católica de Ecuador, Quito, Ecuador & Fundación Uru, Quito, Ecuador
  • 2. Fundación Uru, Quito, Ecuador & Instituto Nacional de Biodiversidad, Quito, Ecuador
  • 3. Instituto Nacional de Biodiversidad, Quito, Ecuador & Clemson University, Clemson, South Carolina, USA

Description

Metopiellus chasqui sp. nov.

Figs 1 D – F, 2 D – F

Type material.

Holotype ♂ (QCAZ 280376): “ Ecuador. Pichincha: Otongachi Reserve -0.330510, -78.934420, 1087 m. 20-Feb-2020, E. Tapia & N. Dupérré ”; deposited in QCAZ. Paratypes (4 ♀, same general locality as type): -0.330510, -78.934420, 1087 m (QCAZ 280377 to 280380).

Additional, non-type material.

Ecuador • 4 ♂, 4 ♀: Zamora Chinchipe; Las Orquídeas; -4.2482, -78.6595; 877 m; E. Tapia; Sifting litter; 29-Jul-2024; QCAZ 280381 to 280388.

Comparative diagnosis.

Metopiellus chasqui resembles M. emavieirae in the presence of a pair of (rather than a single) vertexal structures and by having two pairs of mediolateral pronotal projections. However, it can be distinguished from it by the vertexal and median pronotal processes being transversely ridge-like, and by the lateral pronotal processes having a posterior acute point (vs. horn-like vertexal and pronotal structures in M. emavieirae). The aedeagi differ strongly, with that of M. chasqui having a strongly bifurcate dorsal armature, and that of M. emavieirae being subdivided subapically into four curved, spatulate tips.

Description.

Avg. BL = 3.2 mm (N = 2; see Table 1 for other measurements). Body (Fig. 1 D – F) densely setose and brown-reddish; eyes prominent, borne on small elevated base, comprising ~ 8 ommatidia; head widest at base, rounded, narrowed anterad, with two posterior vertexal foveae (Fig. 1 E) immediately in front of two low posterior vertexal ridges; antennae with 11 antennomeres, antennal scape about as long as antennomeres II – VIII combined, antennomere II as long as III – VII combined, III – VI elongate, V longer than others, VII globular, VIII smallest, IX – XI forming weak club, IX and X transverse, XI almost as long as IX and X combined, tapered in apical two-thirds; pronotum densely setose, with 4 acute lobes, lateral lobes each with posterior acute point, median ones forming oblique ridges, prominent at their inner corners; each elytron with two basal foveae, and with longitudinal impressions extending from them posteriorly approximately two-thirds elytron length; protibia rather slender. Aedeagus (Fig. 2 D – F) with basal bulb asymmetrical and globose, with basal rounded margin, elevated distad, dorsal diaphragm elongate oval; tegmen with ventral portion long, slender, curved dorsad and then distad apically; articulated armature robust, deeply bifurcated, one bifurcation is hook-like, longer and evenly tapered, other more robust with small projection oriented towards distal apex of basal bulb.

Distribution.

This species probably only occurs in the Otongachi Reserve in northern Ecuador, in the province of Pichincha (Fig. 3). We believe the ‘ additional material’ cited from Zamora-Chinchipe to be mislabeled, since that locality is over 400 km to the south, and located on the Amazonian side of the Andean crest, an unlikely distribution for a flightless beetle species. The male genitalia is identical between the two alleged localities.

Etymology.

The specific epithet “chasqui” refers to the agile messengers of the Inca Empire, evoking the beetle’s slender posterior legs.

Notes

Published as part of Tapuy-Avilés, Yarina, Díaz-Guevara, David R. & Caterino, Michael S., 2026, First country record of Metopiellus Raffray, 1908 (Staphylinidae, Pselaphinae, Metopiasini) from Ecuador, with description of two new species, pp. 127-135 in ZooKeys 1266 on pages 127-135, DOI: 10.3897/zookeys.1266.169869

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Linked records

Additional details

Biodiversity

Collection code
QCAZ
Material sample ID
QCAZ 280376 , QCAZ 280377 , QCAZ 280381, 280388
Event date
2020-02-20 , 2024-07-29
Verbatim event date
2020-02-20 , 2024-07-29
Scientific name authorship
Tapuy-Avilés & Díaz-Guevara & Caterino
Kingdom
Animalia
Phylum
Arthropoda
Order
Coleoptera
Family
Staphylinidae
Genus
Metopiellus
Species
chasqui
Taxon rank
species
Taxonomic status
sp. nov.
Type status
holotype , paratype
Taxonomic concept label
Metopiellus chasqui Tapuy-Avilés, Díaz-Guevara & Caterino, 2026