Megalomyrmex drifti Kempf

Longino, John T., 2010, A taxonomic review of the ant genus Megalomyrmex Forel (Hymenoptera: Formicidae) in Central America, Zootaxa 2720, pp. 35-58 : 44

Megalomyrmex drifti Kempf

( Figs 1 C, 4B)

Megalomyrmex drifti Kempf, 1961: 504 , figs 9–11. Holotype worker, paratype workers, queen: Dirkshoop, Surinam [MZSP] (not examined). Brandão, 1990: 448, description of male. See also: Kempf, 1970: 362.

Measurements. Worker: HW 0.40–0.55, HL 0.53–0.65, SL 0.40–0.55, ML 0.65–0.80 (n=20, from Brandão, 1990).

Geographic range. Widespread in tropical South America, north through Central America to southern Mexico.

Biology. This species occurs in moist to wet forest habitats, in mature and second growth forest. Most collections are from below 600 m elevation, but collections from 1500 m cloud forest are known. Workers and occasionally queens are moderately abundant in Winkler samples of sifted litter. In Costa Rican wet forest I found a nest in a dead stick in the leaf litter; it contained abundant workers, brood, alate queens, and males. The collection was made on 9 November 2002, the height of the wet season.

Comments. Specimens I have examined from Costa Rica have a pair of carinae on the worker and queen clypeus, a character used as part of the species diagnosis by Kempf (1961). However, specimens from Honduras to Mexico lack the clypeal carinae. They are very similar in most other respects, and I consider this geographic variation within a single species.

Material examined. COSTA RICA: Guanacaste: Bosque Humedo, Santa Rosa Nat. Park, 10°51'N, 085°37'W, 300 m, 12 Jul 1985 (J. Longino); Heredia: 7 km SW Pto. Viejo, 10°24'14"N, 084°02'22"W, 160 m, mature wet forest, 19 Apr 2007 (Gilberth H / Felix C); 16 km SSW Pto. Viejo, 10°19'03"N, 084°02'56"W, 500 m, 11 Jul 2006 (Gilbert H / Johanna H); Casa Plastico, 17 km S Pto. Viejo, 10°18'N, 084°02'W, 550 m, 22 Jan 1989 (J. Longino); La Selva, 8 km SW Pto. Viejo, 10°24'N, 084°03'W, 150 m, 17 Jul 1986 (J. Longino); 10 km SE La Virgen, 10°20'N, 084°05'W, 500 m, wet forest, 9 Nov 2002 (J. Longino); 11 km ESE La Virgen, 10°21'N, 084°03'W, 300 m, montane wet forest, 15 Feb 2004 ( ALAS); 11 km SE La Virgen, 10°20'N, 084°04'W, 500 m, 19 Feb 2003 ( ALAS); Limón: Hitoy Cerere Biol. Reserve, 09°40'N, 083°02'W, 100 m, mature and second growth wet forest, 1 Sep 1985 (J. Longino); Puntarenas: Sirena, Corcovado National Park, 08°29'N, 083°36'W, 5 m, 18 Dec 1990 (J. Longino); Manuel Antonio Nat. Park, 09°23'N, 084°09'W, 20 m, 27 Jul 1985 (J. Longino); Rancho Quemado, Osa Peninsula, 08°42'N, 083°33'W, 200 m, 15 Dec 1990 (J. Longino); 13 km SSW Pto. Jimenez, 08°24'24"N, 083°19'42"W, 130 m, tropical rainforest, 10 Mar 2008 (J. Longino); GUATEMALA: El Progreso: 3.7 km SW Morazán, 14°54'18"N, 090°09'13"W, 460 m, tropical dry forest, 8 Jul 2007 (M. Branstetter); 12 km N San Agustin Acasaguastlan, 15°02'30"N, 089°58'00"W, 1200 m, oak pine forest, 3 Jun 1991 (R. S. Anderson); Izabal: 5 km NW Morales, 15°30'50"N, 088°51'56"W, 250 m, 2º lowland tropical rainforest, 17 May 2009 ( LLAMA); 16 km ESE Morales, 15°24'46"N, 088°42'37"W, 415 m, 19 May 2009 ( LLAMA); Petén: Cerro Cahuí, 17°00'09"N, 089°43'03"W, 250 m, treefall gap in tropical moist forest, 22 May 2009 ( LLAMA); Parq. Nac. Tikal, 17°14'25"N, 089°37'19"W, 270 m ( LLAMA); 13 km NW Machaquilá, 16°26'44"N, 089°33'00"W, 400 m, 27 May 2009 ( LLAMA); Suchitepéquez: 5.5 km S Vol. Atitlán, 14°31'39"N, 091°11'48"W, 1056m, riparian wet forest, 18 Jun 2009 (R. S. Anderson); HONDURAS: Olancho: 14 km WSW Catacamas, 14°47'59"N, 086°00'51"W, 600 m, tropical moist forest, 13 May 2009 (J. Longino); MEXICO: Chiapas: Nahá, 16°58'27"N, 091°35'09"W, 950 m, montane wet forest, 14 Jul 2007 (J. Longino); 2.5 km S Nuevo San Juan Chamula, 16°07'25"N, 091°26'44"W, 750 m, montane evergreen forest (roadside), 22 Jul 2007 (R. S. Anderson); 6 km SW Ocosingo, 16°52'02"N, 092°04'43"W, 1400 m, wet oak pine forest, 16 Sep 1992 (R. S. Anderson); 8 km SE Salto de Agua, 17°30'56"N, 092°18'09"W, 100 m, 2º wet forest, 14 Jun 2008 ( LLAMA); 2 km SE Custepec, 15°43'15"N, 092°57'03"W, 1520 m, mesophil forest, 17 May 2008 ( LLAMA); Playón de la Gloria, 16°08'12"N, 090°55'00"W, 155 m, lowland wet forest, 27 Jun 2008 ( LLAMA); Lago Metzabok, 17°07'32"N, 091°37'51"W, 570 m, lowland wet forest, 6 Jun 2008 ( LLAMA).

Figures

FIGURE 1. Variation in mandibular dentition among (A) foreli, (B) symmetochus, (C) drifti, (D) incisus, (E) mondaboroides, and (F) silvestrii.