Azteca andreae

This species constructs large, conspicuous globular carton nests at the base of the stem or near the crown of Cecropia trees.

Identification
Guerreo et al. (2010) - Azteca andreae is a member of the Azteca aurita group with the body completely covered with small, widely scattered pits (foveate surface) bearing a very short white hair; scapes short, SI 57–61.

A. andreae is close to Azteca schimperi but can be distinguished by morphological characters of gynes and males; the major workers of the two species are indistinguishable. A. andreae gynes conspicuously lack pilosity over the entire body, while A. schimperi gynes are densely covered with erect hairs on the head and mesosoma. The anteromedial portion of the clypeus protrudes more in A. andreae than in A. schimperi; the masticatory margin of the mandibles of A. andreae is armed with blunt teeth, while A. schimperi has sharp teeth. The scapes of A. andreae are significantly shorter than those of A. schimperi (0.80–0.86 vs. 0.94–1.01 mm, respectively); the posterior margin of the head is much more excavated in A. andreae than in A. schimperi, and the posterolateral corners are also more angular in the first species; another important character amongst the females of both species is the color: A. andreae females are a dark reddish brown, while A. schimperi females are uniformly brown.

The males of both species are very similar in color, type and distribution of hairs, and wing venation; however, when we examined the male genitalia of both species, we found that there are conspicuous differences. The pygostyle on A. andreae is smooth and shiny, thin, long, and with the distal half curved downwards and squared at the tip, while those on A. schimperi are short, thick and with a rounded tip.

The major workers of both species are indistinguishable, although the workers of A. andreae have a relatively smaller head; however, the ranges of both species overlap. The minor workers are also undifferentiated, but A. andreae have thin, protruding tube-shaped propodeal spiracles, whereas A. schimperi are open at the propodeum.

The females of Azteca lanuginosa, A. schimperi and A. andreae are related to each other and show a clear gradation in the quantity, distribution and type of body hair. The first species is the only one of them with an abundant, erect pilosity all over the body, including the gaster (Longino 2007); it becomes sparse in A. schimperi and disappears altogether in A. andreae (in the latter two species, the gaster is devoid of any hair).

Distribution based on Regional Taxon Lists
Neotropical Region: French Guiana.

Biology
Guerreo et al. (2010) - This species constructs large, conspicuous globular carton nests at the base of the stem or near the crown of Cecropia trees. Alain Dejean has observed and collected several A. andreae nests from trees in French Guiana, the vast majority of which were Cecropia obtusa Trecul. A. andreae can also nest on C. palmata Willd, which also often shelters Azteca alfari or Azteca ovaticeps. The nests observed by A. Dejean always were in pioneer vegetation highly-altered through human activity.

All nests collected contained colonies with many workers, dozens of winged females and few males; for example, type series of this species came from a colony with hundreds of workers, hundreds of winged females (only 55 were collected), five male, several brood and pupae, although no queen was observed. Other collections made by A. Dejean produced colonies with some physogastric females.

Nomenclature

 *  andreae. Azteca andreae Guerrero, et al., 2010: 54, figs. 1-2 (w.q.m.) FRENCH GUIANA.

Worker
(N=5): HLA 1.18–1.36, HLB 1.20–1.46, HW 1.20–1.36, SL 0.84–0.96, EL 0.20–0.26, CI 100–102, SI 67–75.

Palpal formula 4,3. Middle and hind tibiae lacking apical spur. Same combination of characters as Azteca schimperi in Longino (2007). Minor workers with tube-like propodeal spiracles projecting outwards, unlike those of A. schimperi.

Queen
Holotype: HLA 1.42, HLB 1.48, HW 1.08, AHW 0.72, SL 0.82, EL 0.34, OCW 0.08, CI 76, SI 58, MTSC 0.

Paratypes (N=7): HLA 1.38–1.42, HLB 1.46–1.52, HW 1.06–1.10, AHW 0.70–0.76, SL 0.80–0.86, EL 0.32–0.36, OCW 0.06–0.08, CI 75–80, SI 57–61, MTSC 0.

Head: Palpal formula 4,3. Dorsal surface of mandibles smooth and shiny; from an oblique angle from above, weak longitudinal waves can be observed that are not visible in full dorsal view, and with scattered small and widely-spaced holes, each with a short hair on the basal surface, with long hairs behind masticatory margin and anterior half of the outer margin of the mandibles; masticatory margin armed with strong apical and blunt tooth, sub-apical tooth, followed by very rounded teeth extending to the basal margin. Clypeal plate without conspicuous pilosity; medial clypeal lobe strongly convex and protruding, extending well beyond the lateral clypeal lobes. Head sub-rectangular, longer than wide; cephalic capsule in lateral view strongly convex in the front; posterior margin with blunt angulations, deeply excavated in the middle of the V-shape. Scape not reaching posterior margin of cephalic corner; funiculus covered with dense, long and appressed pilosity.

Mesosoma: Smooth and shiny, without conspicuous pilosity. Dorsal surface of propodeum much longer than posterior surface, the latter with a short projection at the base, tube-shaped and facing posteriorly. Edge of metapleural gland orifice bears long, golden hairs. Middle and hind tibiae lacking apical spur.

Metasoma: Petiolar node strongly subtriangular with rounded apex; anterior face of petiole excavated, posterior face nearly twice the length of anterior face; petiolar posteroventral lobe weakly convex behind, straight in the anterior half. Tergites and sternites of the gaster shiny.

Head, mesosoma, petiole and legs dark, reddish brown, gaster yellowish brown with some darker areas. Body shiny.

Male
(N=4): HLA 0.70–0.72, HW 0.67–0.68, SL 0.11–0.12, EL 0.30, CI 94–97, SI 16–17.

Head: Mandibles sub-triangular, outer edge twice as long as inner edge, masticatory margin unarmed, with only a small projection in the middle of margins and a sharp apical tooth; a basal tooth differentiates masticatory and basal margins. Clypeal plate strongly convex, as medial clypeal lobe extends well beyond small, lateral clypeal lobes; surface smooth with small foveae near anterior ridge of clypeal plate. Scapes small, trapezoidal, thin at base and wider distally; pedicel small, nearly equal to maximum scape width; second funicular segment roughly twice as long as scape; remaining funiculus little longer than scape; scape with smooth surface and a few scattered hairs; funicular segments 3–11 with long, dense and appressed pilosity, surface densely punctate and dull. Eyes large, located near anterior half of the cephalic capsule, separated from mandible insertion by less than 0.1 mm; eyes break the plane on side of head. Lateral ocelli protruding slightly above vertex in dorsal view. Margins of the cephalic capsule, above the eyes, slightly convex; posterolateral corners rounded.

Mesosoma: Parapsidal furrows weakly developed. Anepisternum and katepisternum divided by a deep mesopleural groove. Anterior and posterior surfaces of propodeum undifferentiated. Propodeal spiracles visibly protruding.

Metasoma: Petiolar node rectangular with rounded corners and straight dorsal face; anterior surface much longer than posterior surface; petiolar node partly fused to gaster. Tergites and sternites smooth and shiny. Pygostyle thin and long, with distal half curved downwards and squared at the tip, smooth and shiny.

Body dark brown, shiny, slightly punctate in some areas, covered with very sparse decumbent, long white hairs.

Type Material
Holotype (gyne): FRENCH GUIANA, Sinnamary, 5°22’39’’N 52°57’35’’W, Carton nest in Cecropia sp tree, 24 Jul 2008, (A. Dejean, P-J Male, S. Groc and J. H. C. Delabie) ; paratypes: 7 gynes, same locality, ,CPDC,, , , ,.

Etymology
Azteca andreae is named in honor of Andrea Dejean, the third author’s wife, in acknowledgment of her considerable editorial help with myrmecology papers in English.