Forelius damiani Guerrero & Fernandez, 2008

Guerrero, R. J. & Fernández, F., 2008, A new species of the ant genus Forelius (Formicidae: Dolichoderinae) from the dry forest of Colombia., Zootaxa 1958, pp. 51-60 : 53-56

Forelius damiani Guerrero & Fernandez sp. nov.

(Fig. 1, 2 & 3)

Worker measurements. Holotype. TL 1.56, HL 0.48, HW 0.38, EL 0.10, EW 0.08, IOD 0.24, COD 0.10, SL 0.40, PSW 0.01, PSL 0.01, ISPD 0.10, PL 0.10, PHM 0.08, MsL 0.44, CI 79, OI 125, SI 105.

Paratypes and non types (n= 38): TL 1.40 - 1.68, HL 0.42 - 0.50, HW 0.36 - 0.42, EL 0.10 - 0.12, EW 0.08 - 0.10, IOD 0.22 - 0.32, COD 0.04 - 0.10, SL 0.36 - 0.44, PSW 0.01 - 0.02, PSL 0.01 - 0.02, ISPD 0.10 - 0.16, PL 0.08 - 0.14, PHM 0.06 - 0.10, MsL 0.44 - 0.58, CI 79 - 90, OI 120 - 150, SI 95 - 132.

Worker diagnosis. Mandible with four teeth and two denticles. Pronotum in profile relatively low and flat, with 2 erect setae. Dorsum of mesonotum and propodeum with very fine punctation. Mesopleural and metapleural regions shining, with sparse pubescence. Propodeal spiracle circular <0.02 mm diameter.

Worker description. Head flattened dorsoventrally, longer than wide (full face view). Vertex of head weakly concave. Palpal formula 6:4. Anteromedial clypeal plate with shallow concavity and long, ventrally curved setae about same length as closed mandibles. Clypeal margin with a long median seta and two long lateral setae projecting forward. Long erect seta on middle inner margin of each torulus; long seta behind each torulus. Scape short, reaching posterior margin of head. Mandible with apical tooth elongate, twice as long as subapical tooth; subapical tooth followed by a denticle, a tooth, another denticle, and a basal tooth separating masticatory margin from basal margin. Mesosoma (lateral-view) straight with slight mesonotal groove. Mesonotum and propodeum with decumbent scattered pubescence; very fine punctuation on dorsum of mesonotum and dorsum of propodeum. Mesopleuron and metapleuron shining, with sparse pubescence. Propodeal spiracle circular. Posterior face and dorsal face of propodeum convex; dorsal face longer than posterior face. Outer face of anterior coxa with two setae; proximal seta longer than distal seta; inner face of middle and posterior coxae with distal setae; femora and tibiae with dense pilosity. Scale present and strongly inclined anteriorly; petiolar spiracle at base of scale. Dorsum of gaster with abundant pubescence; first gastric (third abdominal) tergite without setae, second gastric tergite bearing 2 setae, third gastric tergite bearing 4 setae and fourth tergite bearing 6 setae. Head and mesosoma dark brown; gaster, petiole, legs, scape and mandible light brown; teeth of mandibles slightly darker than mandible; funicular segments darker than scape.

Queen and male. Unknown

Holotype worker. Colombia: Magdalena; Santa Marta; Vda. Mosquito; 11°10'23.6" N 74°10'45" W 96 m; pitfall; 24-26.Feb.2007; D. Ramirez, coll. Deposited in ICN Insect Collection, Instituto de Ciencias Naturales, Universidad Nacional de Colombia, (Bogota D.C., Colombia). Paratypes: 22 workers, all from the same locality and date as the Holotype, deposited in BMNH (1w), CASC (4w), CEUM (2w), CWEM (1w), CPDC (1w), IAvH (2w), ICN (2w), IFML (2w), JTL (1w), LACM (1w), MCZ (1w), MIZA (1w), MZSP (1w), PSW (1w), USNM (1w).

Additional material examined: Colombia: (10w), Bolivar; Zambrano; Hda. Monterrey; 9°45' N 74°49' W 70 m; pitfall; 01.Aug.1993 F. Fernandez & G. Ulloa, coll. Costa Rica: (3w), Guanacaste; 10°48'N 85°41'W; 100 m; at tuna bait; 14.Jun.1985; xeric scrub on rocky ridge; J. Longino, coll. [ LACM ENT 141815]. (1w), Guanacaste; Santa Elena Peninsula; 10° 53'N 85° 45'W; 08.May.2002; J. M. Jacobs, coll. [ JTLC 000009256]. (1w), Guanacaste; 8km S Santa Cecilia; 10°59'N 85°26'W; 650 m; 24.Jan.1991; Wet forest. Strays; J. Longino, coll. [INBIOCRI001282672]. (1w), Heredia; La Selva Biological Station; 10°26'N 84°01'W; 01.May.1994; J. Longino, coll. [INBIOCRI001260978]. (1w), Puntarenas; Pita; 10°10'N 84°55'W; 200 m; Sweep sample of roadside vegetation; 13.Jul.1984; J. Longino, coll. [ LACM ENT 141813].

Specimen records provided by P. S. Ward (pers. comm.): Costa Rica: Guanacaste; 1km E Playa Nancite; PN Santa Rosa; 10°48'N 85°41'W; 100 m; 5.Apr.2000; Low, open tropical dry forest, in gully, on serpentine; On trail between Playa Naranjo and Playa Nancite, within the watershed of Quebrada Nancite. P. Ward, coll. USA: Texas. Cameron Co. Resaca de la Palma State Park. 25°59'N 97°34'W; 10m; 16.Apr.2006; Subtropical thorn woodland; P. Ward, coll.

Geographic distribution: Colombia (Magdalena, Bolivar), Costa Rica (Guanacaste, Heredia and Puntarenas), USA (Texas).

Etymology: The species name honors our colleague and friend Damian Ramirez, who collected and loaned the ants from his thesis research.

Natural History: Forelius damiani n. sp. was collected in lowland dry forest of the Sierra Nevada de Santa Marta, a tropical forest with an open canopy dominated by Bursera simaruba (L.) Sarg. (Burseraceae), Bursera glabra (Jacq.) Triana & Planch and Pereskia colombiana Britton & Rose (Cactaceae). The habitat is subjected to occasional human disturbance resulting from the extraction of timber. It was also collected in the dry forest of Zambrano (Bolivar, Colombia), but we have no specific information about floristic composition from this site. However, this locality is a transition zone between gallery forest and tropical dry forest. This species is restricted to lowland forest and scrub vegetation, from sea level to 650 m elevation.

The specimens from Costa Rica were collected in open tropical dry forest, xeric scrub, and synanthropic habitats in wet forest areas. Although the genus is generally adapted to dry climates, this species can extend into wet climate areas in the presence of frequent human disturbance.

Although no complete nest of F. damiani has been collected, the large number of specimens collected from the type locality with only one pitfall trap (150 workers) indicates that its colonies could be composed of more than one hundred workers, foraging in large numbers.