Azteca snellingi

Specimens of the type series were collected at different heights on the canopy in the San Lorenzo forest, Panama. Two were collected at 21m from a Pouteria caimito (Ruiz & Pav.) Radlk. (Sapotaceae) tree. Others were collected at 20m and 23.7m height from Luehea seemannii Planch. & Triana. (Tiliaceae). (Guerreo et al. 2010)

Identification
Guerreo et al. (2010) - Azteca snellingi is a member of the Azteca aurita group with a large head, slightly wider than long, with margins strongly convex; metanotal groove wide and deep; workers have reddish brown head and dark brown body.

This species is close to A. aurita and Azteca pilosula. While workers of A. aurita and A. pilosula are undistinguishable (Longino 2007), those of A. snellingi have a distinctly larger head, as long as it is wide. Posterior margin of the head with a deep concavity and continuous while the other two species has a V-shaped concavity. In general A. snellingi is a species with workers (reproductive castes unknown) larger than A. aurita and A. pilosula workers (CI 99–101 vs. A. aurita: CI 85–88, A. pilosula: CI 89–90). Sides of head strongly convex in A. snellingi, however, some A. pilosula workers (Azteca lacrimosa syntype and lectotype, synonymized by Longino 2007) have curved margins but not become as convex as in A. snellingi. Azteca snellingi mandibles, with the dorsal surface as those of Azteca aurita, but those of A. snellingi are more opaque. Furthermore, the anterior region of the mesonotum is higher and more globular in A. snellingi. Metanotal groove is wide and deep in A. snellingi whereas other two species is absent or inconspicuous.

Azteca snellingi also differs from A. aurita and A. pilosula in the distribution and kind of the hairs on the body. A. snellingi workers have no erect hairs in the petiolar node in contrast A. pilosula workers have erect hairs on the anterior face and apex of the petiole. Lateral margins of petiole lacking of any pilosity whereas A. pilosula has erect, conspicuous and scattered setae. A. snellingi workers have no erect hairs on the posterior margin of the head whereas A. pilosula workers posterior margin of head with sparse, very short erect setae grading into white pubescence (Longino 2007). A. snellingi is reddish-brown and the body is entirely dark brown, which is notable in this species as no other known worker in the aurita group presents this coloration pattern.

Distribution based on Regional Taxon Lists
Neotropical Region: Panama.

Castes
Known only from the worker caste.

Nomenclature

 *  snellingi. Azteca snellingi Guerrero, et al., 2010: 61, fig. 10 (w.) PANAMA.

Worker
Holotype: HLA 1.56, HLB 1.66, HW 1.60, SL 1.30, EL 0.30, CI 103, SI 83.

Paratype (N56): HLA 1.44–1.58, HLB 1.52–1.66, HW 1.44–1.60, SL 1.18–1.32, EL 0.24–0.30, CI 99–101, SI 81–88.

Head: Palpal formula 4,3. Mandibles completely flat, apical tooth much larger than anterior; dorsal surface with dense longitudinal sculpture; surface rough and opaque. Median clypeal lobe strongly convex, extending well beyond lateral clypeal lobes. Sides of head strongly curved, corners of posterolateral margins angled; posterior margin (vertex) strongly concave. Scapes curved, not reaching posterolateral corners of head.

Mesosoma: In lateral view, pronotum weakly convex or straight toward anterior, without a posterior face. Mesonotum strongly convex, rising well above pronotum like a hump; globular in front, gently flattened posteriorly. Metanotal sulcus large and deep. In lateral view, propodeum roughly flat, dorsal face much larger that the posterior face. Middle and hind tibiae lacking spurs.

Metasoma: Petiolar node large, with rounded end, sloped at front; posterior face nearly twice as large as the anterior face. Ventral lobe conspicuously uniformly convex.

Body entirely covered with fine, dense punctations. Pubescence thin and whitish, appressed, covering each tagma; some setae conspicuous near base of ventral lobe of petiole and sternites 2–4. Body with shiny, weakly reflective surface. Part of head, scape and mandibles dark reddish-brown. Posterior third of the head dark brown. Mesosoma, legs, petiole and gaster dark brown.

Type Material
Holotype (major worker): PANAMA, Colon, San Lorenzo Forest (SLPA), area metropolitana, IBISCA project, 9u16.7939N, 79u 58.4999W, manual collection in the canopy, 26 Feb 2008 (N. B. Espirito Santo & S. P. Ribeiro) ; paratypes: 6 major workers, same data as for holotype 1, ; 1, ; 1, ; 1, ; 1, ; 1,.

Etymology
This ant is named in honor of Roy Snelling, our colleague and friend, who contributed notably to the knowledge of Hymenoptera.