Pheidole sagittaria

According to Longino (1997), sagittaria is common in mature wet forests. The two nests he found were, respectively, in a piece of rotten wood on the ground and under the loose bark of a dead tree trunk. (Wilson 2003)

Identification
See the description in the nomenclature section.

Distribution
Mostly montane regions of Costa Rica from 500 to 1600 m (Longino 1997).

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica.

Nomenclature

 *  sagittaria. Pheidole sagittaria Wilson, 2003: 502, figs. (s.w.) COSTA RICA.

Description
DIAGNOSIS Similar to Pheidole christopherseni, Pheidole exquisita, Pheidole nigricula, Pheidole nitella and Pheidole pygmaea, differing as follows.

Major: light brown; head strongly flattened dorsoventrally, so that in side view it is narrowly rectangular; in addition, the head and mandibles together in full-face view are heart-shaped or (adding flattening top to bottom) shaped like an arrowhead; propodeal spines reduced to denticles; apex of petiolar node pointed; carinulae cover most of anterior fourth of dorsal head surface, and almost all of the rest of the body smooth and shiny.

Minor: eye very large, oval, set far forward on head; propodeal spines reduced to denticles; almost all of head and body smooth and shiny.

MEASUREMENTS (mm) Holotype major: HW 0.72, HL 0.76, SL 0.38, EL 0.10, PW 0.34. Paratype minor: HW 0.34, HL 0.36, SL 0.32, EL 0.06, PW 0.22.

COLOR Major: body light brown, appendages yellowish brown.

Minor: body yellowish brown, appendages dark yellow.



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

Type Material
COSTA RICA: Rio Toro Amarillo, near Guápiles, Limón, col. W. L. Brown.

Etymology
L sagittaria, pertaining to arrows, referring to the head shape of the major.

References based on Global Ant Biodiversity Informatics

 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.
 * Longino J. T., and R. K. Colwell. 2011. Density compensation, species composition, and richness of ants on a neotropical elevational gradient. Ecosphere 2(3): 16pp.
 * Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
 * Smith M. A., W. Hallwachs, D. H. Janzen. 2014. Diversity and phylogenetic community structure of ants along a Costa Rican elevational gradient. Ecography 37(8): 720-731.