Wheeler, W.M., 1919
Males were collected with the lectotype series in November 1905. (Wilson 2003)
- 1 Identification
- 2 Distribution
- 3 Biology
- 4 Castes
- 5 Nomenclature
- 6 References
See the description in the nomenclature section.
Keys including this Species
Only known from the Known only from Isla Santa Cruz, Isla Seymour, and Isla San Salvador. An apparent endemic of the Galápagos Islands. The species appears to be rare. (Wilson 2003)
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- williamsi. Pheidole williamsi Wheeler, W.M. 1919c: 267 (s.w.q.m.) ECUADOR (Galapagos Is). Senior synonym of seymourensis: Wilson, 2003: 249.
- seymourensis. Pheidole williamsi var. seymourensis Wheeler, W.M. 1924a: 108 (s.w.) ECUADOR (Galapagos Is). Junior synonym of williamsi: Wilson, 2003: 249.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
From Wilson (2003): A small, yellow member of the diligens group, closest to Pheidole crozieri of Peru, but also with some similarities to Pheidole vafella, as well as Pheidole rufipilis and the mostly South American species listed with rufipilis (q.v.), differing from crozieri as follows.
Major: dark yellow; pronotum in side view peaked in a blunt angular profile, and weakly bilobous in dorsal-oblique view; occiput weakly concave; anterior margin of pronotal dorsum carinulate; apex of petiolar node in side view tapering to a blunt point.
Minor: petiolar node in side view relatively low, and in rear view with dorsal border strongly convex.
MEASUREMENTS (mm) Lectotype major: HW 1.04, HL 1.10, SL 0.74, EL 0.16, PW 0.52. Paralectotype minor: HW 0.48 (approximately), HL 0.62, SL 0.66, EL 0.12, PW 0.30.
COLOR Major: concolorous dark yellow.
Minor: body brownish yellow, appendages dark to medium yellow.
The Wheeler types may be faded; minors collected on Isla San Salvador in 1991 (P. Oromi) have light brown bodies.
Figure. Upper: lectotype, major. Lower: paralectotype, minor. Scale bars = 1 mm.
GALÁPAGOS ISLANDS: Isla Santa Cruz. Museum of Comparative Zoology - as reported in Wilson (2003)
Named after Harrison Williams, leader of a Galápagos collecting expedition. (Wilson 2003)
- Wheeler, W. M. 1919d. Expedition of the California Academy of Sciences to the Galapagos Islands, 1905-1906. XIV. The ants of the Galapagos Islands. Proc. Calif. Acad. Sci. (4)2(2 2: 259-297 (page 267, soldier, worker, queen, male described)
- Wilson, E. O. 2003. Pheidole in the New World: A dominant, hyperdiverse ant genus. Harvard University Press, Cambridge, MA. (page 249, fig. major, minor described, Senior synonym of seymourensis)