Pheidole boltoni

This species is a montane cloud forest specialist. In the tropics ant abundance declines dramatically between 1500m and 2000m and ants are very difficult to find above 2000m. Pheidole boltoni occurs in a narrow band at the very upper edge of ants’ natural occurrence. Several nests have been collected under epiphyte mats in recent branch and treefalls. One nest (the types of P. humida) was collected in a rotten log. (Longino 2009)

Identification
See the description in the nomenclature section.

Distribution
This taxon was described, and is only known, from Costa Rica.

Nomenclature

 *  boltoni. Pheidole boltoni Wilson, 2003: 666, figs. (s.w.) COSTA RICA. Senior synonym of humida: Longino, 2009: 17.
 * humida. Pheidole humida Wilson, 2003: 614, figs. (s.w.) COSTA RICA. Junior synonym of boltoni: Longino, 2009: 17.

Description
DIAGNOSIS A small, bicolorous species belonging to an ambiguous cluster composing the “carapuna complex” (Pheidole boltoni, Pheidole carapuna, Pheidole cornicula, Pheidole cuprina, Pheidole eriophora, Pheidole jivaro, Pheidole manuana, Pheidole tristicula) close to the flavens group. All are relatively small in size, with the major possessing a reduced mesonotal convexity and cephalic sculpturing, composed in turn entirely of longitudinal carinulae that extend to or close to the occipital border viewed in full face. All also have a minor with a broad, concave occiput, which lacks a nuchal collar. Among these species, P. boltoni is distinguished as follows.

Major: relatively flat profile of the promesonotum in dorsal-oblique view; eye set well forward so that its anterior margin is the same distance from the anterior genal border as the Eye Length; small, obtuse-angulate mesonotal convexity; and smooth, shiny occiput, postpetiolar node, and first gastral tergite.

MEASUREMENTS (mm) Holotype major: HW 1.06, HL 1.06, SL 0.62, EL 0.18, PW 0.48. Paratype minor: HW 0.60, HL 0.60, SL 0.60, EL 0.12, PW 0.34.

COLOR Major: head dark reddish yellow, rest of body light reddish brown, legs dark yellow.

Minor: concolorous dark yellow.



'''Figure. Upper: holotype, major. Lower: paratype, minor. Scale bars = 1 mm.'''

Type Material
Longino (2009):

Pheidole boltoni Wilson, 2003: 666, figs. Holotype major worker and associated paratype minor worker: Costa Rica, Heredia, 8km N Volcan Barba, 10°12'N 84°06'W, 1830m, 4-14 Jul 1986 (Longino #1329) (examined).

Pheidole humida Wilson, 2003: 614, figs. Holotype major worker and associated paratype minor worker: Costa Rica, Puntarenas, Monteverde, 1550m, 20 May 1979 (P. S. Ward #3450) (MCZ) (examined).

Etymology
Named in honor of the distinguished British ant systematist Barry Bolton.