Dorymyrmex pyramicus

Identification
Cuezzo and Guerrero (2011) - Worker Promesonotal profile continuous, strongly convex. Head, mesosoma, and legs reddish-yellow with gaster dark brown to black. Psammophore reaches the posterior margin of hypostoma. Queen Head subquadrate, maximum width at level of compound eyes; scape surpassing the posterior margin of head by no more than its maximum width; mandibles feebly striated with four teeth and two denticles on the masticatory margin; posterior margin of head straight. Forewing with only one large cubital cell. Male Head wider than long; posterior margin of head medially concave; scape long, surpassing the level of compound eyes, pygostyle poorly developed.

This species was described by Roger as Prenolepis pyramica from one worker collected in Bahia, Brazil, and transferred to Dorymyrmex by Mayr (1870). Unfortunately, Wheeler (1902) erroneously stated that Formica insana Buckley (1866) (Dorymyrmex insanus) was an “undoubtedly synonym” of D. pyramicus. Originally, Formica insana was described from Texas and southern states of the United States. Workers of D. insanus are concolorous black to dark brown, as Snelling (1973) says, differing from workers of D. pyramicus that are typically bicolored, as we describe above. Nevertheless, this mistake persisted, authors having considered D. pyramicus as a species with a very large distribution, from the south part of the United States throughout the Caribbean area to the north of Argentina. We only found one worker of D. pyramicus in Colombia, but there are bibliographic records that confirm its presence in this country (Fernandez and Sendoya 2004). Apparently, D. insanus and D. pyramicus are only sympatric in Central America (Cuba and Guatemala) and in the north part of South America (Colombia, Venezuela, and Northern Brazil). Beside color, D. pyramicus and D. insanus can be differentiated by the shape of head in full-face view and the shape of the promesonotal profile (continuous in D. pyramicus, interrupted at its end in D. insanus).

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Belize, Brazil, Colombia, Costa Rica, Cuba, Greater Antilles, Guatemala, Guyana, Lesser Antilles, Mexico, Suriname, Uruguay.

Biology
This species was found attending extrafloral nectaries of the plant Turnera subulata in northeastern Brazil Caatinga vegetation. Dorymyrmex pyramicus, classified as a dominant species, was a common attendant at the extrafloral nectaries.

Nomenclature

 *  pyramicus. Prenolepis pyramica Roger, 1863a: 160 (w.) BRAZIL. Emery, 1888c: 362 (m.); Gallardo, 1916a: 56 (q.); Wheeler, G.C. & Wheeler, J. 1951: 183 (l.); Goni, et al. 1983: 366 (k.). Combination in Dorymyrmex: Mayr, 1870b: 947; in D. (Conomyrma): Forel, 1913l: 244; in Conomyrma: Kusnezov, 1952g: 430; in Dorymyrmex: Shattuck, 1992c: 85. Current subspecies: nominal plus albemarlensis, alticonis, garbei, guyanensis, mesonotalis, nigriventris, peruvianus, rubriceps. See also: Emery, 1895c: 331; Snelling, R.R. 1973b: 4; Cuezzo & Guerrero, 2011: 19.

Worker
Cuezzo and Guerrero (2011) - (n = 10): HL: 0.78–0.88; HW: 0.73–0.78; EL 0.20–0.25; EW: 0.1–0.13; SL: 0.78–0.85; WL: 1.18–1.20; CI: 89–94; SI: 97–100; REL: 26–29; OI: 50–52; TLI: 137–152.

Head, mesosoma, and petiole concolorous reddish yellow; gaster always darker than the rest of the body, frequently dark brown to black. Whitish and sparse pubescence covering all body tagma. Head: posterior margin of head feebly emarginated medially. Psammophore with short hairs forming a triangle; the hairs in the top line are dispose near to the foramen magnum and do not reach the oral cavity. Upper seta line of psammophore close to anterior margin of foramen magnum. Mesosoma: pronotum with two subdecumbent short setae. Promesonotal profile strongly convex. Mesonotum not angulated, as in Dorymyrmex insanus. Propodeal tubercle well developed and directed dorsally. Declivitous face of propodeum, straight. Metasoma: petiolar scale pointing dorsally.

Queen
Cuezzo and Guerrero (2011) - (n = 2): HL: 1.15–1.18; HW: 1.18–1.2; EL: 0.33–0.4; EW: 0.13–0.15; IOD: 0.73; SL: 0.93–0.95; WL: 1.93–1.95; CI: 102-103; SI: 80-81.

Color and pubescence as in worker. Head: subquadrate; scape surpassing the posterior margin of head by no more than its maximum width; mandibles feebly striated, four teeth and two denticles on the masticatory margin; posterior margin of head straight; external margin of compound eye included in head surface in frontal view; ocelli hyaline, close to the posterior margin of head. Mesosoma: parapsidal furrows not well developed but parallels, axilla not divided medially. Anepisternum incompletely separated from katepisternum by a short suture. Forewing with only one close cubital cell; radial cell open. Metasoma: petiolar scale low, stout, and rounded apically.

Male
Cuezzo and Guerrero (2011) - (n = 2): HL: 0.6–0.64; HW: 0.7–0.75; EL: 0.2–0.26; EW: 0.13–0.14; SL: 0.34; WL: 1.48–1.50.

Body color similar to worker and queen. Head: subquadrate, wider than long; lateral side of clypeus feebly projected forward; mandibles thin, with four teeth, apical tooth more than twice longer than the others; scape long, surpassing posterior margin of compound eyes. Mesosoma: parapsidal furrows present and parallel, axilla not divided medially; forewing with one close radial cell and no cubital nor discoidal cell. Hindwing with two basal cells. Metasoma: petiole stout and low, directed dorsally, ventral process round, feebly developed. Pygostyle poorly developed; gonystylus stout covered with few erect setae; digitus short and no cuspis. Aedeagus with serrate ventral border.

Etymology
Cuezzo and Guerrero (2011) - The name of pyramicus refers to the typical tubercle or cone on propodeum present in all species of Dorymyrmex, giving to the propodeal angle an appearance of pyramid. Several Dorymyrmex species are known as “pyramid ants.”