Acropyga fuhrmanni

Lapolla (2004) - A. fuhrmanni has been found in litter, and in a variety of habitats from grassy, open areas to rainforests. It has been recorded occurring up to an elevation of 950 m. Wheeler (1935) stated that this species was also found in cacao plantations. Queens are trophophoretic, having been recorded with at least one mealybug species belonging to the genus Neochavesia. Wheeler (1935) noted that workers and queens (he unfortunately did not indicate if the queens were alate or dealate however) carried mealybugs when a nest was disturbed.

Identification
From Lapolla (2004):

Diagnosis - Worker: 8 segmented antennae; head usually broader than long; mandible with four distinct teeth, a short diastema separating basal tooth from other teeth. Queen: as in worker with modifications expected for caste. Male: 9 segmented antennae; eyes close to anterior margin of head; parameres long and rectangular, though they taper toward apex; digiti distinctly long, in dorsal view appearing nearly as long as penis valves. Compare with Acropyga ayanganna and Acropyga smithii.

This species is fairly easy to recognize with its 8-segmented antennae and relatively large eyes, set close to head's anterior margin. Some specimens have been examined where the gaster is darker than the rest of the body giving them an almost bi-colored appearance. However, all other characters suggest these specimens are con specific with specimens that are yellow colored throughout. Additionally, size of the worker is variable with a series of specimens from Costa Rica being the largest (TL: 2.3-2.6), while most A. fuhrmanni are around 1.6 mm in total length. Unfortunately despite being one of the more common species in collections, only one male specimen is known, and it was in very poor condition. Therefore, as males are collected across the range of this species, they should be examined to address any questions of conspecificity. A. fuhrmanni is a member of the decedens species-group and is the sister species to the goeldii complex of species. Its penis valves are elongated as in Acropyga smithii, though they are not as wide.

Distribution
This taxon was described from Colombia.

From LaPolla (2004): This species has a wide range from Central America (recorded as far north as Costa Rica) south throughout tropical South America.

Nomenclature

 *  fuhrmanni. Rhizomyrma fuhrmanni Forel, 1914e: 12 (w.q.) COLOMBIA. Weber, 1944: 97 (m.l.). Combination in Acropyga (Rhizomyrma): Emery, 1925b: 29. Senior synonym of berwicki: LaPolla, 2004a: 42.
 * berwicki. Acropyga (Rhizomyrma) berwicki Wheeler, W.M. 1935f: 325, fig. 1 (w.) TRINIDAD. Junior synonym of fuhrmanni: LaPolla, 2004a: 42.

Worker
From LaPolla (2004) - Head: yellow to brownish-yellow; head typically broader than long; covered in a layer of appressed to suberect hairs, with erect hairs on posterior margin; posterior margin entire; eyes often appearing (relatively) large and prominent, close to anterior margin; 8 segmented, incrassate antennae; scape fails posterior margin by about the length of pedicel; clypeus with abundant erect hairs; mandible with 4 distinct teeth; only a slight gap between clypeal margin and the inner mandibular margin. Mesosoma: in lateral view anterior portion of pronotum with a short, shelf-like extension before rising steeply toward mesonotum; mesonotum and posterior pronotum bearing numerous erect hairs; a thick layer of appressed and suberect hairs on mesonotum underneath several erect hairs; mesonotum slightly higher than propodeum; metanotal area distinct; propodeum bearing numerous erect and suberect hairs; declivity steep. Gaster: brownish-yellow; petiole thick and erect; gaster yellow; covered in a layer of thick appressed hairs, with erect hairs scattered throughout.

Measurements (n=34): TL: 1.39-2.56; HW: 0.434-0.642; HL: 0.43-0.612; SL: 0.272-0.484; ML: 0.446-0.698; GL: 0.496-1.19; CI: 93.23-111.94; SI: 58.62-79.08.

Queen
From LaPolla (2004) - As in worker with modifications expected for caste and with the following differences: anterior portion of mesonotum slightly overhangs pronotum; dorsum covered with a thick layer of appressed hairs and scattered erect hairs; scutellum of variable pilosity.

Measurements (n=5): TL: 2.55-2.88; HW: 0.516-0.714; HL: 0.488-0.626; SL: 0.306-0.518; ML:0.798-1.2; GL: 1.23-1.5; CI: 99.61-114.06; SI: 56.46-75.58.

Male
From LaPolla (2004) - Unfortunately the single known male specimen was in such poor condition (shriveled) as to prevent description of the mesosoma; therefore only a description of the head, gaster and genitalia follows. Head: brownish-yellow, darker toward apex around 3 prominent ocelli; head longer than broad, oval in appearance; covered in a layer of appressed hairs; eyes large, breaking outline of head in full frontal view; eyes very close to anterior margin of head as in other castes; 9 segmented, incrassate antennae; apical segment about as long as proceeding 3 segments; scape reaches to posterior margin; clypeus narrow, with a few erect hairs; mandible with long apical tooth and a sharp basal angle not fully developed into a distinct tooth; gap exist between inner mandibular margin and anterior clypeal margin. Gaster: brownish-yellow; covered in layer of appressed hairs, with scattered erect hairs throughout. Genitalia: parameres in lateral view, long and rectangular, though tapering toward apex and covered in numerous erect hairs; in dorsal view, parameres with slight lateral expansions; cuspi tubular in shape, tapering toward apices which bear several short, peg-like teeth where they meet with digiti; digiti long, in dorsal view appearing almost as long as penis valves; tip of digiti slightly anvil-shaped, bearing short, peg-like teeth toward dorsal surface.

Type Material
Rhizomyrma fuhrmanni, Forel, 1914: 12 (w.q.). 3 syntype workers, 1 syntype queen, COLOMBIA: Puerto de los Pobres, Cauca border, Dep. Antioquia, elev. 720 m (MHNG) [examined]. The designated lectotype is a worker labeled JSL TYPE # 116 and is deposited at MHNG. Emery, 1925: 29, first combination in Acropyga; Weber, 1944: 97, description and key and description of larvae and male.

Acropyga (Rhizomyrma) berwicki, W.M. Wheeler, 1935b: 325 (w.). 18 syntype workers, TRINIDAD: San Raphael, B.W.I. (E.J.H. Berwick) (MCZC) [examined]. NEW SYNONYM.

Additional References

 * Wheeler, W. M. 1935. Ants of the genus Acropyga Roger, with description of a new species. J. N. Y. Entomol. Soc. 43: 321-329.