Pheidole absurda

Pheidole absurda excavates deep nests in soil. Colonies are granivorous and store seeds in special chambers. Creighton (1966) studied the habits of this species (as P. ridicula) in south Texas. (Longino 2003)

Identification
See the description in the nomenclature section and, from The Ants of Costa Rica: Minor worker: head length 0.74mm, head width 0.68mm, scape length 0.65mm, Webers length 0.91mm (n=1). Head flattened behind; promesonotum evenly arched, mesonotal suture absent; propodeal spines short, sharp, upturned; face shining, largely smooth, with longitudinal carinae between eyes and frontal carinae, faint transverse carinae near posterior border; mesosoma largely smooth and shining, with transverse rugae on anterodorsal pronotum and propodeal dorsum; gaster smooth and shining; dorsal pilosity abundant, of moderate length, flexuous; color light yellow brown.

Major worker: head length 2.38mm, head width 1.79mm, scape length 0.76mm (n=1). Face largely smooth and shining; hypostomal margin with no medial tooth, pair of subtriangular teeth located closer to midline than to recessed teeth flanking mandibles; dorsal pilosity abundant on mesosoma and gaster; pilosity on head sparse, with only a few setae projecting from sides of head in face view.

Distribution
The Brownsville area of extreme southern Texas south to Costa Rica. I have seen material from the Yucatan Peninsula and Guatemala. Kempf (1972b) reports absurda from the "Guianas," but this needs verification. (Wilson 2003)

This taxon was described from Guatemala. It is also found in the United States, Mexico, Honduras, Nicaragua, and Costa Rica.

Biology
Near Campeche I found a nest in moist clay of a thorn forest. Soil nests are also reported by Longino (1997) in Costa Rica and by Creighton (1966) in Texas. According to Creighton, the nest entrance is an inconspicuous hole 2- 5 mm in diameter, leading to a diffuse system of galleries and chambers that descend as much as a meter into the ground. A mature colony contains at least 75 majors and 300 minors. The colonies harvest seeds (Amaranthus palmeri at Creighton's study site) and store them in granary chambers. The minors strip the ovary shards away from the seeds, and the majors crack them open. The majors also serve as very effective guards, using their mandibles like wire clippers to chop off appendages of arthropod intruders. In observation nests they proved more than a match for other Pheidole and the native fire ant Solenopsis geminata. (Wilson 2003)

Costa Rica
Monteverde (San Luis Valley): edge of forest patch in upper San Luis valley; nest in soil well beneath soil surface; nest exposed during excavation (collected by Jeremy Miller). (reported by Longino)

Nomenclature

 *  absurda. Pheidole absurda Forel, 1886b: xlvii (s.) GUATEMALA. Emery, 1890b: 48 (w.). Senior synonym of ridicula: Wilson, 2003: 646. See also: Emery, 1894k: 54.
 * ridicula. Pheidole ridicula Wheeler, W.M. 1916f: 29, fig. 1 (s.) U.S.A. Junior synonym of absurda: Wilson, 2003: 646. See also: Creighton, 1966b: 1.

Description
From Wilson (2003): DIAGNOSIS A large member of the tristis group distinguished by the disproportionately large, elongate head of the major. The major is also characterized by a nearly complete lack of sculpturing on the head and body other than carinulae found on the dorsal surface of the head from the level of the eyes forward; very low meso somal convexity; propodeal spines small and erect. Minor: occiput broad, lacking nuchal collar; body almost completely smooth, lacking any sculpturing except for carinulae on the dorsal head surface at the level of the eye and anterior to it.

MEASUREMENTS (mm) Lectotype major: HW 1.80, HL 2.38, SL 0.82, EL 0.24, PW 0.84. Paralectotype minor: HW 0.64, HL 0.68, SL 0.64, EL 0.14, PW 0.42.

COLOR Major: head reddish yellow, mandibles medium reddish brown, rest of body and appendages yellowish brown.

Minor: body light brown, appendages brownish yellow.



'''Figure. Upper: major. The body is drawn from a specimen from 10 km east of Campeche, Mexico, col. E. O. Wilson, compared with the lectotype major in ; the head is drawn from the lectotype major. Lower: paralectotype, minor. Scale bars = 1 mm.'''

Type Material
- as reported in Wilson (2003)

Type Locality Information
GUATEMALA: Retalhuleu.

Etymology
L absurda, foolish, silly, referring to the very large, elongate head of the major. (Wilson 2003)