Pheidole viserion

Pheidole viserion has been collected from three sites in Papua New Guinea from montane primary forests and from a lowland habitat transitioning between primary and secondary forest. In addition to being found in the leaf litter, it was also found foraging in a hollow trunk above the ground. (Sarnat et al. 2016)

Identification
Sarnat et al. (2016) - Pheidole viserion is the only member of the cervicornis group that is uniformly yellow in color. The species is most similar to Pheidole barumtaun, but the majors of P. viserion can be distinguished by the more striate mandibles and first gastral tergite, and cephalic sculpture. The minor workers are quite similar to those of P. barumtaun, and are best differentiated by the uniform yellow color.

Distribution based on Regional Taxon Lists
Indo-Australian Region: New Guinea.

Worker
Minor

Nomenclature

 *  viserion. Pheidole viserion Sarnat, Fischer & Economo, 2016: 19, figs. 1d, 2d, 5, 14 (w.s.) PAPUA NEW GUINEA.

Worker
Major HW 2.09–2.13, HL 2.06–2.11, SL 1.05–1.08, FL 1.60–1.68, EL 0.18–0.20, ML 1.50–1.67, PSL1 0.57–0.68, PSL3 0.70–0.74, PeL 0.59–0.62, PeW 0.14, PpW 0.43–0.46, CI 99–101, SI 50–52 (n = 3). Color uniformly shining yellow, major sometimes with darker yellowish brown head. Head square; posterior margin describing a broad and shallow ‘V’. Head strongly convex in lateral view without any impression of the vertex. Posterolateral lobes separated by a deep median impression giving them a strongly convex appearance. Antennal scrobe absent. Antennal scapes long with erect hairs; strongly curved basally to conform to convexity of head. Frontal carina indistinct; blending with parallel carinulae an undistinguished by strength or length. Anterior medial clypeal margin weakly emarginated. Mandible bidentate apically; entirely striate. Hypostomal bridge with broad, distinct median tooth; submedian teeth of subequal length to median tooth. Clypeus with strong median carina. All surfaces of head covered by fine, parallel, non-intersecting carinulae. Carinulae longitudinal from anterior clypeal border to frons, then diverging laterally and becoming finer. Carinulae of posterolateral lobes arcuate to distinctly transverse. Mesosoma armed with long strongly produced pronotal spines, mesonotal spines and propodeal spines. Pronotal spines of subequal length as propodeal spines; directed anterolaterally and becoming downcurved apically. Mesonotal spines approximately eye-length, strongly upturned. Propodeal spines relatively straight, directed posterolaterally, becoming weakly downcurved apically. Pronotal dorsum transversely striate; mesosoma otherwise mostly smooth and shining. Petiole relatively long, approximately equal in length to propodeal spine. Petiolar node cuneiform with weakly emarginate vertex. Postpetiole approximately equal in height to petiole; in dorsal view strongly transverse with small lateral projections and weakly sculptured. Entire first gastral tergite longitudinally striate.

Minor HW 0.62–0.68, HL 0.75–0.83, SL 1.04–1.12, FL 1.23–1.44, EL 0.12–0.15, ML 1.09–1.24, PSL1 0.53–0.63, PSL2 0.50–0.60, PSL3 0.45–0.60, PeL 0.38–0.44, PeW 0.07–0.10, PpW 0.16–0.19, CI 81–87, SI 162–169 (n = 10). Strongly shining yellow. Head elongate ovoid, tapering behind the eyes to a narrow posterior margin. Nuchal carinae thin but distinct and forming collar around posterodorsal head margin. Antennal scapes with erect hairs, distinctly surpassing posterior head margin. Head completely smooth except for a few arcuate carinulae between the eyes and mandible. Mesosoma with extremely long spines on the pronotum and propodeum, and shorter spines on the mesonotum. Pronotal spines approximately same length as tibiae; directed anterolaterally and becoming downcurved apically. Mesonotal spines approximately eye-length; directed posterolaterally and straight. Propodeal spines fused basally into thick upright trunk before diverging; strongly bifurcate, directed posterolaterally and becoming downcurved apically. Petiole very elongate. Petiolar node conical.

Etymology
The species name refers to Viserion, the cream and gold colored dragon of Daenerys Targaryen, a fictional character from the George R. R. Martin’s novel A Song of Ice and Fire. The name is a noun in apposition and thus invariable.

References based on Global Ant Biodiversity Informatics

 * Sarnat E. M., G. Fischer, and E. P. Economo. 2016. Inordinate spinescence: taxonomic revision and microtomography of the Pheidole cervicornis species group (Hymenoptera, Formicidae). PLoS ONE 11(7): e0156709. doi:10.1371/journal.pone.0156709