Holcoponera avus

Specimens of this species were collected in litter samples from primary montane forest, suggesting this species likely lives and/or forages in the leaflitter. It is only found at the type locality, which might indicate a preference for montane, preserved forest areas.

Identification
Camacho et al. (2020) - Size comparatively small (TL 2.57−2.75). Mandible smooth and shiny on their dorsal face. Small eyes, with five ommatidia on their largest diameter. Scape surpassing vertex margin at least by the same length as its apical width. Dorsal profile of mesosoma flat, metanotal impression absent. Propodeal spiracle positioned at the propodeum lateral margins, turned posteriorly and forming a tubuliform projection, its opening above the level of integument. Propodeum without any lobes, in lateral view. Metacoxal spine present. Segments I and II of gaster completely costulate.

Gnamptogenys avus is similar to Gnamptogenys mina. Gnamptogenys avus has compound eyes (only one ommatidium in G. mina), the scape surpasses the vertex margin (not reaching the vertex margin in G. mina), and the propodeal spiracle is protruding (less protruding in G. mina). Despite the morphological similarities between G. mina and G. avus, both species do not appear to be closely related, according to phylogenomic analysis of Gnamptogenys species relationships (Camacho et al., in prep).

Distribution based on Regional Taxon Lists
Neotropical Region: Guyana.

Known only from the type locality, Mt. Ayanganna, Guyana.

Nomenclature

 *  avus. Gnamptogenys avus Camacho, Franco & Feitosa, 2020: 462, fig. 16 (w.) GUYANA.

Worker
Worker: HL 0.60–0.62; HW 0.47–0.50; ML 0.24–0.27; SL 0.45–0.50; EL 0.1–0.08; WL 0.91–0.83; PL 0.25– 0.23; GL 0.84–0.80; TL 2.57–2.75; CI 78.33–80.64; SI 95.74−100; OI 21.27−16 (n=2). Small size. Brown-coppery color, with appendages and gaster the same color. Body predominantly covered by thin, long, suberect hairs. Mandible smooth and shiny, without rugulae or striations on the dorsal surface. Head dorsum covered by long longitudinal costulae, deep and slightly irregular, semiparallel from the anterior margin of clypeus to vertex margin; vertex smooth and shiny, without hairs; surface of costulae covered by punctuation, giving them a rough appearance; intervals between costulae smooth and shiny. Mesosoma completely covered by wide costulae, approximately 0.035 mm in width, with straight margins on the dorsal surface; pronotum with transverse costulae anteriorly and several subparallel costulae on the dorsal surface. Declivitous face of propodeum covered by costulae, the same width and appearance as on mesosoma. Petiole with same sculpture as mesosoma. Coxae always covered by transverse costulae, narrower than on mesosoma. Segments I and II of gaster with same sculpture as mesosoma. Anterior face of first gastral segment bare, smooth with sparse rugulae.

Mandible triangular. Anterior margin of clypeus strongly convex in frontal view. Lateral margins of head straight and subparallel, slightly tapered anteriorly. Occipital corners extend ventrally, forming a small ridge. Antennal scape narrow, almost twice as wide apically than at its base; scape surpassing the vertex margin by the length of the apical width of scape. Eyes with at least five ommatidia, located slightly behind the anterior half of the head in frontal view. Vertex margin straight. Dorsal profile of mesosoma compact and flat in lateral view, without mesonotal impression. Lateral margins of declivitous face of propodeum parallel; dorsal and declivitous face of propodeum differentiated, forming a light ridge between the two; propodeal spiracle positioned at the propodeum lateral margins, turned posteriorly and forming a tubuliform projection, its opening above the level of integument. Propodeum without lobes or projections. Metacoxal spine acute and relatively large. Anterior and posterior margins of petiole subparallel in lateral view; petiole not pedunculated. Subpetiolar process predominantly opaque and subquadrate, very large, occupying more than half of the ventral surface of the petiole; subpetiolar process with a fenestra positioned centrally. Prora large and visible in lateral view.

Camacho et al. (2020) - Worker: HL 0.74−0.79; HW 0.65−0.70; ML 0.38−0.44; SL 0.50−0.55; EL 0.04−0.05; WL 0.81−1.01; PL 0.25−0.28; GL 0.94−1.00; TL 3.16−3.44; CI 85.71−90.32; SI 75.93−79.63; OI 5.77−7.41 (n=8).

Body brown-copper to reddish-brown to black, with slightly lighter appendages, coppery-brown to coppery. Body predominantly covered by medium length, medium thickness and erect hairs. Scape covered by many short suberect hairs.

Mandible smooth and shiny without rugulae or striae on the dorsal surface. Head dorsum covered by long longitudinal costulae, shallow and subparallel; vertex with rugulae and inconspicuous striae. Pronotal dorsum longitudinally costulae. Dorsal surface of mesonotum, metanotum and propodeum covered by longitudinal and subparallel costulae, without smooth and shiny areas. Superior third of declivous face of propodeum with longitudinal costulae gradually becoming transverse on the inferior portion. Procoxae covered by transverse rugulae; mesocoxa and metacoxa covered by irregular striations and heavily punctuated. Petiole covered by inconspicuous rugulae on dorsal and lateral surfaces, with smooth regions and punctuated regions. Segments I and II of gaster smooth and shiny, covered by rugulae and irregular striations at the base of hairs. Anterior face of the first gastral segment bare, smooth and shiny and with some inconspicuous rugulae.

Mandible triangular. Anterior margin of clypeus strongly projected anteriorly, giving it a triangular appearance in frontal view. Lateral margins of head straight and subparallel, slightly tapered anteriorly. Antennal scape does not reach vertex margin; scape ranging from brown to yellowish-copper from the base to the apex. Eye with a single ommatidium located slightly behind the anterior half of the head in frontal view. Vertex margin slightly concave in its central region, giving vertex corners a slightly angled aspect.

Dorsal profile of mesosoma compact and flat in lateral view, without metanotal impression. Lateral margins of the declivity of propodeum distinguishable by the presence of two subparallel carinae; dorsal surface and declivity of propodeum distinguishable by a weak arcuate carina at the junction between them; propodeal spiracle at the same level of the integument; propodeal spiracle distant from declivity margin by a distance three times larger than its opening; opening of propodeal spiracle very wide and facing sideways. Propodeum armed with denticles. Metacoxal spine absent.

In lateral view, anterior and posterior faces of petiole slightly convergent, giving petiole a slightly triangular shape; petiole not pedunculated. Subpetiolar process predominantly opaque and subquadrate, very large, occupying more than half of the ventral surface of the petiole; subpetiolar process with a translucent fenestration which occupies about 2/3 of its area. Dorsal surface of gaster covered by small striae at the base of each hair, with smooth and shiny areas in between; posterior margin of the first tergite of gaster without leathery sculpture; in dorsal view, the first segment of gaster trapezoidal, anterior angles rounded, but differentiated. Prora prominent. Intercaste (first description): HL 0.76; HW 0.66; ML 0.38; SL 0.48; EL 0.12; WL 0.96; PL 0.28; GL 1.00; TL 3.38; CI 84.61; SI 72.73; OI 18.18 (n=1). Differing from workers by the presence of three ocelli well-developed and arranged in triangle on the head dorsum; compound eye slightly convex, with about eight ommatidia in its largest diameter; body more robust with the presence of scutum and scutellum

Etymology
From Latin avus=ancestor/grandfather, in reference to the species basal position within its clade, according to phylogenomic data. Fittingly, the name also honors the first author’s grandfather, whose love for nature was always a source of admiration and inspiration. The name is applied here as a noun in apposition.