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Pheidole williamsi WheelerHNS
Etymology Named after Harrison Williams, leader of a Galapagos collecting expedition.
diagnosis A small, yellow member of the diligensHNS group, closest to crozieriHNS of Peru, but also with some similarities to vafellaHNS, as well as rufipilisHNS and the mostly South American species listed with rufipilisHNS (q.v.), differing from crozieriHNS 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.
range Known only from Isla Santa Cruz, Isla Seymour, and Isla San Salvador. An apparent endemic of the Galapagos Islands. The species appears to be rare.
Biology Males were collected with the lectotype series in November 1905.
Figure Upper: lectotype, major. Lower: paralectotype, minor. GALAPAGOS ISLANDS: Isla Santa Cruz. Scale bars = 1 mm.
Found most commonly in these microhabitats: 1 times fern.
Collected most commonly using these methods: 1 times En cebo de atún, 1 times Aspirator.
Elevations: collected from 850 - 1032 meters, 995 meters average