Brachymyrmex heeri

 Brachymyrmex heeri nests under stones and other objects, often in disturbed areas.

Identification
Small workers (1.2 to 2mm) with nine segmented antenna. Erect hairs present on head, mesosoma and gaster. Color varies from yellow to brown.

Distribution
Central America, South America and the Caribbean. Also introduced in a few locations in Europe and in the Galapagos Islands.

This taxon was described from Switzerland. It is also found in Ecuador, Brazil, Bolivia, Colombia, Venezuela, Argentina, Suriname, Paraguay, French Guiana, Guatemala, Costa Rica, Dominican Republic, Haiti, Puerto Rico, Lesser Antilles, Bermuda, Bahamas and Trinidad and Tobago.

Regional Notes
In Haiti this species was "found to be very common beneath stones, boards etc. on the shores of the salty Lake Assuei (Haiti)" (Wheeler and Mann 1914).

Wheeler (1908) found "several small colonies under stones" in Puerto Rico.

Costa Rica
Longino 2004 - This is a common species of synanthropic habitats in Costa Rica. It can be found in small parks in the middle of San José, in hotel landscaping, along road edges, in scrubby second growth vegetation, and in pastures. It occurs in almost any bioclimatic region: dry Guanacaste lowlands, wet Atlantic slope lowlands, Central Valley urban areas, and roads and pastures near Monteverde cloud forest. Nests are often under stones on the ground but also occur in cavities in low vegetation. Colonies are polygynous, with multiple dealate queens often occurring together in nests. Workers are omnivorous and opportunistic foragers.

St Vincent
The opening text of the source (Forel 1893) for the following collection records, by H. H. Smith, states "These notes are given in full, as it is thought that the precise localities in which the species were met with may be of interest to local naturalists."

(57). Moderately common in communities of a few hundreds at most. The formicarium is formed under a stone, or at the roots of grass and weeds, generally on open ground; but if my hasty identifications are correct, the species ranges to the tops of the highest mountains. So far as I have observed, the formicarium consists only of one or two simple chambers, with a short connecting passage. The ants are moderately active, less so than allied forms. They are sometimes beaten from foliage.

(57 a). Wallibou (leeward); thickets near the seashore. Oct. 6 th. Community of several hundreds under a stone. Sandy ground.

(57 b). Cumberland (leeward); open valley near the sea-level., Male and female found together under a stone (not copulated). Oct. 8 th.

(57 c). Islet fronting Chateaubelais Bay (leeward), Oct. 31 st. Rocky ground, thickets near sea-level. Workers found scattered under stones.

(57 d). Workers. Note was lost. Probably obtained by beating.

(57 e). Soufriere Volcano, 2500 ft. Sept. Scrubby growth found in moss, & c,

(57 f). Wallilobo Valley (leeward), Nov. 8 th; open hill-side, 500 ft. A female referred to this species, found alone under sod on a rock.

(57 g). Bowwood Valley, near Kingstown, 800 ft. Oct. 15 th. Second growth-, beaten from branches.

(57 h). Not noted. Doubtfully referred to this species.

(57 i). Windward side; open sandy valley of the Dry River, near the sea. Jan. 2 nd. From two nests under stones. The species is common in this vicinity.

(57 j). Same locality and date as (57 i). An unusually large community under a stone. The winged females and males (especially the males) were very numerous.

(57 k). Bank near seashore, between Georgetown and the Dry River (windward). Jan. 3 rd. Nest at the roots of grass.

(57 l). Workers, doubtfully referred to this species; near Grand Sable Estate (windward). Jan 3 rd. Seashore thicket; side of a rock under loose earth.

Nomenclature

 *  heeri. Brachymyrmex heeri Forel, 1874: 91, figs. 16, 20 (w.) SWITZERLAND. Forel, 1876: 52 (q.m.). See also: Santschi, 1923b: 664. Current subspecies: nominal plus basalis, fallax.

Description
Ouvriere: Longueur 1, 2 a 2mm

Tout le corps court, large, trapu. Mandibules munies de cinq dents (les autres especes en ont quatre). Pas trace d'ocelles (les autres especes ont trois ocelles). Yeux composes d'environ 35 facettes chacun ; ils sont situes legerement en avant du milieu des bords lateraux de la tete. Palpes maxillaires longs; le second et le troisieme article sont plus longs que les quatre autres. Les palpes labiaux sont assez longs aussi; leurs quatre articles sont egaux entre eux. Chaperon (c.) en forme de capuchon (comme chez le Brachymyrmex patagonicus), sans carene, recouvrant un peu les mandibules, fortement voute de droite a gauche, moins fortement d'avant en arriere: Il est arrondi posterienrement, parfois aussi un peu echancre au milieu de son bord posterieur ; il ne se prolonge pas ou presque pas entre les articulations des antennes (entre les aretes frontales). Aire frontale distincte, triangulaire, souvent un peu arrondie a son angle posterieur. Sillon frontal distinct. Aretes frontales courtes, divergentes, a peine recourbees. La tete, un peu aplatie en dessus, basse en arriere, est echancree a son bord posterieur. Premier article du fouet des antennes un peu plus long que les deux suivants ensemble ; dernier (8m.) article du fouet aussi long que les trois qui le precedent a. la fois (fg.) Thorax tres court, surtout le mesonotum et le pronotum qui sont voutesis et forment ensemble seulement les 2/5 de sa longueur totale. Un sillon transversal enfonce, assez etroit, separe le mesonotum du metanotum; ce sillon ne renferme pas de petite spirale (il en renferme une chez le Brachymyrmex tristis). La face basale du metanotum est extremement courte, convexe (mtb); sa face declive, longue, large et plate (mtd), va en pente douce et egale jusqu'au pedicule. Eperons des pattes anterieures tres forts. Ecaille encore plus fortement inclinee en avant que chez la Plagiolepis pygmaea (e). Premier segment de l'abdomen prolonge en avant et recouvrant l'ecaille ; abdomen grand. D'un jaune plus on moins brunatre, grisatre ou rougeatre. Dessus de la tete et de l'abdomen plus fonce. Tout le corps luisant; chaperon et face declive du metanotum lisses; quelques rugosites assez grossieres sur les joues; tout le reste tres finement rugueux ponctue. Pubescence grisatre, assez forte sur l'abdomen, un peu moins forte sur la tete, plus faible sur le thorax, les pattes et les antennes, nulle sur le chaperon et sur la face declive du metanotum. Poils epars, un peu partout, sauf sur les pattes et sur les antennes. Les deux stigmates posterieurs sont gros et tres distincts.

Type Locality
Forel (1874) reported "Jardin botanique de Zurich, dans la serre des Orchidees tropicales. (Botanical Garden of Zurich, in the greenhouse of tropical orchids.)" It is now clear that the type specimens must have been transported to the European botanical garden in tropical plant material. This has created the odd situation of Brachymyrmex heeri being a New World species with a type locality of Switzerland.

Additional References

 * Wheeler, W. M. 1908a. The ants of Porto Rico and the Virgin Islands. Bull. Am. Mus. Nat. Hist. 24: 117-158.


 * Wheeler, W. M. and W. M. Mann. 1914. The ants of Haiti. Bull. Am. Mus. Nat. Hist. 33: 1-61.