Acromyrmex coronatus

Acromyrmex coronatus is a montane species found in cloud forest habitats. It is tolerant of cold, wet conditions and colonies can be found in small clearings and gaps in dense cloud forest. Nests are often in or under a piece of dead wood, and often with a superstructure of loose dead leaf fragments. In Monteverde, Costa Rica, it is the main pest in gardens and will come into houses at night to cut bread, cabbage or fruit.

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Brazil, Ecuador, Guatemala, Honduras, Mexico, Panama, Paraguay.

Biology
Jack Longino provides the following notes from Costa Rica:

Acromyrmex coronatus is a montane species found in cloud forest habitats and not in the lowlands. It is tolerant of cold, wet conditions and colonies can be found in small clearings and gaps in dense cloud forest. On the transect on the north side of Volcan Barva it has been found at 1100m elevation but not at 500m or 2000m. On the Central Valley side it has been collected at 1600m elevation at Zurqui. In the Monteverde area it occurs in the community area, up to the highest ridges at 1700m, and down to 800m in the Penas Blancas Valley.

In Monteverde, it is the main pest in gardens and will come into houses at night to cut bread, cabbage, or fruit that has been left out. The nests are often in or under a piece of dead wood, and often with a superstructure of loose dead leaf fragments. They do not excavate soil very extensively if at all. They may be arboreal at times, nesting in a low branch junctions of epiphyte-laden trees.

Lisa Ellis, an undergraduate student with the University of California Education Abroad Program in the late 1980's, carried out a study of A. coronatus foraging during the transition from dry to wet season in Monteverde. She found that foraging was continuous at night, but diurnal foraging only occurred when there had been recent rain. Following a heavy rain, diurnal foraging would commence followed by a gradual cessation over a period of a day or two. Periodic rains during the dry season would initiate a short bout of diurnal foraging, but when the rains became more continuous diurnal foraging became continuous. Thus the lack of diurnal foraging during the dry season was a short-term response to immediate environmental conditions and not a long-term change in colony foraging behavior.

Nuptial flights are common in Monteverde and the distinctively-patterned dealate queens are often seen on the roads. On 9 July 1984 I observed a swarm of males in the canopy of an emergent oak on the ridge crest above Monteverde. Hundreds of males were swarming just above the highest branches of the tree. Later in the day I saw many dealate queens on the roads.

I have observed aggregations of founding queens under epiphyte mats in recent treefalls. Several times I have seen dealate queens out cutting leaves, suggesting that queens need to forage to establish a colony.

Nomenclature

 *  coronatus. Formica coronata Fabricius, 1804: 413 (q.) SOUTH AMERICA. Forel, 1885a: 356 (w.). Combination in Atta: Roger, 1863b: 35; in Atta (Acromyrmex): Forel, 1885a: 355; in Acromyrmex: Bruch, 1914: 216. Subspecies of hystrix: Forel, 1885a: 355. Revived status as species: Dalla Torre, 1893: 152. Senior synonym of: meinerti, modesta, moelleri, ochraceolus and material of the unavailable names flavescens, medianus, obscurior, ornatus referred here: Gonçalves, 1961: 135. Current subspecies: nominal plus andicola, globoculis, importunus, panamensis, rectispinus.
 * meinerti. Atta (Acromyrmex) moelleri st. meinerti Forel, 1893e: 599 (q.) BRAZIL. Emery, 1905c: 45 (w.); Santschi, 1925a: 364 (w.). Combination in Acromyrmex: Forel, 1916: 429. Subspecies of coronatus: Santschi, 1925a: 364. Junior synonym of coronatus: Gonçalves, 1961: 135.
 * moelleri. Atta (Acromyrmex) moelleri Forel, 1893e: 596 (s.w.q.m.) BRAZIL. Combination in Acromyrmex: Forel, 1916: 429. Subspecies of coronatus: Santschi, 1925a: 363. Junior synonym of coronatus: Gonçalves, 1961: 135.
 * modesta. Atta (Acromyrmex) moelleri r. modesta Forel, 1901h: 49 (s.) BRAZIL. Combination in Acromyrmex: Luederwaldt, 1918: 39. Junior synonym of coronatus: Gonçalves, 1961: 135.
 * ochraceolus. Acromyrmex coronatus st. ochraceolus Santschi, 1925a: 365 (w.) BRAZIL. [First available use of Acromyrmex moelleri r. panamensis var. ochraceolus Forel, 1922: 97; unavailable name.] Junior synonym of coronatus: Gonçalves, 1961: 135.