Mycetomoellerius jamaicensis

Occurs in southeastern Florida and on numerous Caribbean islands.

Identification
Trachymyrmex jamaicensis is a unique species in the context of the US American fauna. No other Trachymyrmex shows the combination of large body size, dark coloration, almost quadrate head shape, antennal scrobes extending to posterior corners of head, long scapes, and four tuberculate longitudinal ridges on the first gastric tergite. (Rabeling et al. 2007)

Distribution
This taxon was described from Jamaica. It is also found in Brazil, United States, Cuba, Haiti, Dominican Republic, Puerto Rico, and Bahamas.

In the United States T. jamaicensis occurs only in southeast Florida and the Florida Keys, but it is also widely distributed through much of the Caribbean (see distribution map). Smith (1954) suggested that Trachymyrmex jamaicensis is a non-native species that was recently introduced from the Caribbean, whereas Deyrup (1994) argues for an early, natural introduction because of morphological differences between the Florida and Caribbean populations. A thorough study of population genetics and morphology would be required to test these hypotheses. (Rabeling et al. 2007)

Habitat
In Florida, T. jamaicensis inhabits coastal tropical hardwood hammocks on shallow, sandy, coralline-rock-derived soils.

Biology
From Rabeling et al. (2007): Nests usually have several chambers; Weber (1967) found eight chambers in a colony excavated in the Bahamas. Based on partial nest excavations, Wheeler (1905, 1907) estimated that T. jamaicensis colonies contain 150 to several hundred workers. Due to the increasing urbanization of the coastline, Deyrup (1994) considers T. jamaicensis potentially endangered in Florida, which would give T. jamaicensis the distinction of being the first endangered fungus-growing ant species (IUCN 2006).

Nomenclature

 *  jamaicensis. Atta (Acromyrmex) jamaicensis André, 1893b: 149 (w.) JAMAICA. Wheeler, W.M. 1907c: 713 (q.m.); Wheeler, G.C. 1949: 674 (l.). Combination in Atta (Trachymyrmex): Wheeler, W.M. 1907c: 712; in Trachymyrmex: Gallardo, 1916b: 242. Senior synonym of cubaensis, frontalis, maritima, sharpii: Mayhé-Nunez & Brandão, 2007: 13. Current subspecies: nominal plus antiguensis. See also: Wheeler, W.M. & Mann, 1914: 41; Rabeling, Cover, et al. 2007: 11.
 * sharpii. Atta (Trachymyrmex) sharpii Forel, 1893g: 372 (w.) ANTILLES. Combination in Trachymyrmex: Kempf, 1972a: 254. Junior synonym of jamaicensis: Wheeler, W.M. 1907c: 712. Revived from synonymy: Kempf, 1972a: 254. Junior synonym of jamaicensis: Mayhé-Nunes & Brandão, 2007: 13.
 * maritima. Atta (Trachymyrmex) maritima Wheeler, W.M. 1905b: 107, pl. 7, figs. 7, 8 (w.) BAHAMAS. Combination in Trachymyrmex: Kempf, 1972a: 253. Junior synonym of jamaicensis: Wheeler, W.M. 1907c: 712. Revived from synonymy as subspecies of jamaicensis: Mann, 1920: 428. Junior synonym of jamaicensis: Mayhé-Nunes & Brandão, 2007: 13.
 * frontalis. Trachymyrmex jamaicensis var. frontalis Santschi, 1925d: 238 (w.) HAITI. Junior synonym of jamaicensis: Mayhé-Nunes & Brandão, 2007: 13.
 * cubaensis. Trachymyrmex jamaicensis subsp. cubaensis Wheeler, W.M. 1937b: 459 (w.) CUBA. Junior synonym of jamaicensis: Mayhé-Nunes & Brandão, 2007: 13.

Worker
Diagnosis from Rabeling et al. (2007): HL 1.2–1.35, HW 1.35–1.45, CI 107–113, SL 1.2–1.25, SI 86–89, ML 2–2.1. A large, relatively slender species with relatively long antennae and legs. Antennal scapes surpass posterior corners of head by 1–2 times their maximum diameter. Head shape slightly longer than broad (CI 107–113) in full-face view, sides subparallel behind the eyes, slightly tapering anteriorly between the eyes and mandibular insertions. Posterior margin moderately concave. Clypeus with row of coarse, long hairs on anterior margin, projecting forwards over the dorsal surface of the mandibles; in side view a few shorter erect hairs often present posterior to the anterior row. Preocular carinae relatively short, stopping at about 1/3 the distance between eye and posterior corner of head, always subparallel to frontal carinae, not traversing antennal scrobe. Frontal carinae long, reaching back to posterior corner of head. Antennal scrobe well developed but shallow, extending above the posterior margin of the head as a small tooth. In full-face view, frontal lobes broad, rounded, symmetrical in shape. Anterolateral promesonotal tooth long, thin, sharply pointed, projecting forward and upwards. Propodeal teeth sharply pointed, variable in size, approximately as long as the distance between their bases. Head and mesosoma sparsely tuberculate, with small tuberculi bearing short, fine, recurved setae. In full-face view, two ridges are present on the posterior third of head, between the frontal carinae. Gaster strongly tuberculate, in dorsal view tuberculi form four more or less distinct longitudinal ridges on first gastric tergite. Color dark reddish-black or gray-black, appendages and two petiolar segments usually a lighter reddish-brown.

Queen
Diagnosis from Rabeling et al. (2007): HL 1.25, HW 1.6–1.7, CI 128–136, SL 1.15–1.2, SI 68–75, ML 2–2.05. As in worker diagnosis but with typical caste-specific mesosomal morphology related to wing-bearing and head with small ocelli. In dorsal view, dorsolateral pronotal teeth large and conspicuous, sharp, narrowly triangular. Ventrolateral pronotal teeth large, lobelike (rarely triangular). Mesoscutum with coarse, longitudinal, finely tuberculate rugulae; tuberculi bearing short, stiff, slightly recurved suberect setae. Posterior portion of scutellum bearing two prominent lobelike teeth projecting posteriorly. Pronotal sides, mesopleura, and propodeum with only a few miniscule tuberculi, if any.

Male
Diagnosis from Rabeling et al. (2007): HL 0.72–0.75, HW 0.69–0.75, CI 96–100, SL 0.87–0.99, SI 121–139, ML 2.1–2.4. A comparatively large male with relatively long appendages and antennal scapes. Posterior corners of head much rounded in full-face view, ocelli very large, elevated above remainder of head, forming a short, vertical “turret” in side view. Dorsolateral pronotal teeth unique, taking the form of thin, needlelike spines. Ventrolateral teeth absent. Gaster finely tuberculate, each tubercle bearing a short erect to suberect more or less recurved seta.

Type Material
Two syntype workers (repository unknown)[not examined]. (Rabeling et al. 2007).

Type Locality Information
Jamaica. (Rabeling et al. 2007).

Etymology
André (1893) described T. jamaicensis based on two worker specimens collected by M. Fox in Jamaica (no date given). The species name obviously refers to the Caribbean island on which the types were collected. (Rabeling et al. 2007).

Additional References

 * [[Media:Andre 1893b.pdf|André, E. 1893b. Description de quatre espèces nouvelles de fourmis d'Amérique. Rev. Entomol. (Caen) 12: 148-152 PDF]]


 * Deyrup, M. (1994) Jamaican fungus ant Trachymyrmex jamaicensis (André). In: Deyrup, M. & Franz, R. (Eds.), Rare and Endangered Biota of Florida, Volume IV. Invertebrates. University Press of Florida, Gainesville, Florida, 719–721 pp.


 * IUCN (2006) 2006 IUCN Red List of Threatened Species. Available from: http://www.iucnredlist.org/ (access date: 23 March 2007).


 * Rabeling, C., S. P. Cover, R. A. Johnson, and U. G. Mueller. 2007. A review of the North American species of the fungus-gardening ant genus Trachymyrmex (Hymenoptera : Formicidae). Zootaxa.1-53.


 * Smith, M. R. (1954) Ants of the Bimini Island group, Bahamas, British West Indies (Hymenoptera, Formicidae). American Museum Novitates, 1671, 1–16.


 * Weber, N.A. (1967) The fungus-growing ant, Trachymyrmex jamaicensis, on Bimini Island, Bahamas (Hymenoptera: Formicidae). Entomological News, 28, 107–109.


 * Wheeler, W. M. (1905) The ants of the Bahamas, with a list of the known West Indian species. Bulletin of the American Museum of Natural History, 21, 79-135.