Dorymyrmex agallardoi

Identification
Snelling (1975) - Worker with prominent, posteriorly directed propodeal spine; side of propodeum with coarse, widely spaced rugulae; occiput densely punctulate. Although it does resemble Dorymyrmex planidens in stature, the distinctly rugulose propodeal sides will separate it from that species. The red color is also much less bright than in planidens.

Distribution based on Regional Taxon Lists
Neotropical Region: Chile.

Biology
The species nests in areas with sandy soil or with fine gravel, both on river beds and on hillsides in central Chile. It has been observed foraging mainly on dead insects, and to date it has not been observed collecting honeydew from homopterans, a very generalized behavior in other species of the genus in the country. Its activity seems to be concentrated from December to February, avoiding the hottest periods of the day, and there is no activity with soil temperatures above 48 ° C (Cerpa 2019, Pers. Obs.). Foraging occurs up to a 15 meter radius from the nest. The nest can have up to 3 entrances, although it usually has only one. The nesting cone is usually inconspicuous, and may not exist.

It has been observed to interact aggressively with other ants, quickly avoiding conflict, walking away, or opening its jaws in a threatening manner when contact is unavoidable. Other types of interspecific interactions are unknown.

Nomenclature

 *  agallardoi. Dorymyrmex agallardoi Snelling, R.R. 1975: 6, figs. 12, 13 (w.) CHILE.

Worker
HL 1.05-1.22 (1.19); HW 0.92-1.06 (1.04); SL 1.08-1.23 (1.17); PW 0.60-0.69 (0.69); WL I. 73-1.99 (1.98).

Head. Distinctly longer than broad, CI 87-91 (87); HL a little less than to a little more than SL; SI 110-118 (112). In frontal view, HW greatest a little below midpoint, sides of head slightly convex; occipital margin distinctly concave. Scape extending beyond occipital margin by about one-third its length. Apical margin of clypeus gently, evenly convex in frontal view. Eye on front of head, OMD 0.97-1.04 (1.04) x EL.

Thorax. Slender, PW 0.33-0.37 (0.35) x WL. From above, pronotum about twice as wide as mesonotum, about 1.3 x propodeum. In profile, meso- and metanota forming a continuous, steep slope from pronotum to propodeum, interrupted only by sharply projecting spiracles; posterior margin of metanotum depressed well below dorsal level of propodeum, so that anterior margin of propodeum is abruptly declivitous. Propodeal spine, from above, nearly parallel-sided, apex rounded; in profile, flattened and sharp at apex, base below upper level of propodeal dorsum, directed caudad. In profile, node of petiole with anterior face nearly vertical, dorsal face convex, posterior face strongly sloping; without ventral spines or teeth.

Vestiture. Erect setae general but sparse, variable in length on head, thorax and gaster; those of scape abundant, short, fine; those of tibiae long, acuminate.

Integument. Front of head mostly moderately shiny, lightly shagreened; malar area duller, more closely shagreened; occiput and vertex dull, closely punctulate; head with scattered, setigerous punctures, more numerous on occiput. Pronotum shinier than front of head, with scattered setigerous punctures. Pronotal neck and entire meso-metanotum dull, densely punctulate. Propodeal dorsum similar, but sides slightly shiny and with widely spaced, oblique rugulae. Posterior face of node of petiole with delicate, concentric striae which may be more or less obsolete. Gaster smooth and shiny.

Color. Head and thorax dull reddish; antenna and legs medium brown; gaster blackish.

Type Material
Holotype and four paratype workers: Chile, Prov. Santiago: El Alfalfal, 25 Jan. 1968 (J. Moroni); five paratype workers: Chile, Prov. Santiago: San Jose de Maipo, 29 Nov. 1969 (L. Alfaro). Holotype and two paratypes in ; five paratypes in ; two paratypes in

Etymology
This species is dedicated to the late Angel Gallardo, a pioneer in the systematics and biology of South American ants.

Determination Clarifications
This is very likely the same species that Berg (1890) recorded from Santa Rosa de los Andes, Aconcagua, Chile, Dorymyrmex planidens.

References based on Global Ant Biodiversity Informatics

 * Shattuck S. O. 1994. Taxonomic catalog of the ant subfamilies Aneuretinae and Dolichoderinae (Hymenoptera: Formicidae). University of California Publications in Entomology 112: i-xix, 1-241.
 * Snelling R. R. 1975. Descriptions of new Chilean ant taxa (Hymenoptera: Formicidae). Contributions in Science (Los Angeles) 274: 1-19
 * Snelling R. R., and J. H. Hunt. 1975. The ants of Chile (Hymenoptera: Formicidae) Revista Chilena de Entomología 9: 63-129.