Pheidole nasutoides

This species is only known from type specimens. Repeated attempts by Hölldobler and Wilson (see 1992) and J. T. Longino (1997) to discover additional colonies at and around the type locality have been unsuccessful, suggesting that the species is either very rare or a relatively inaccessible canopy dweller. (Wilson 2003)

Identification
See the description in the nomenclature section.

Distribution
Only known from the type locality.

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

Biology
Holldobler and Wilson (1992): "The type colony was found nesting in a round mass of dried, thatch-like vegetation about 1.5 meters up in the moderately dense foliage of a small tree, which was located at the edge of a secondgrowth forest bordering the open experimental fields of the La Selva station. When the nest was disturbed, more than a hundred major and minor workers of P. nasutoides rushed out and ran in erratic looping patterns to form a spreading wave away from the nest. The resemblance of the majors to Nasutitermes nasute soldiers under similar circumstances was remarkable. In particular, the mask of the Pheidole majors is roughly shaped like that of the nasute termites and contrasts with the light remainder of the body in the same way. The illusion was heightened when the ants were in motion, creating a Nasutitermes like gestalt. Holldobler, who discovered the nest, in fact first thought that the ants were Nasutitermes and nearly passed them by. During the brief time the colony was observed live in the laboratory, the resemblance remained close. Otherwise, the colony seemed typical for a species of Pheidole. Adult males were present, but neither alate nor dealate queens were recovered.

We remain puzzled by our failure to locate other P. nasutoides nests despite prolonged effort in the La Selva area. It is possible that the species is simply very rare, existing in extremely sparse populations. Alternatively, it may be normally a dweller of the high canopy, a zone we did not explore. The nest found was at the edge of a disturbed forest patch, and might have fallen from a higher location."

Nomenclature

 *  nasutoides. Pheidole nasutoides Hölldobler & Wilson, 1992: 19, figs. 1, 2 (s.w.) COSTA RICA. See also: Wilson, 2003: 468.

Description
From Wilson (2003): DIAGNOSIS A medium-sized member of the flavens group, whose major possesses 2 teeth (as opposed to the usual 4 or 5) on the hypostoma; uniquely bicolorous head (see below); promesonotum perfectly semicircular in side view and subangular in dorsal-oblique view. Also, the minor is unusual in its narrow occiput with nuchal collar.

Similar to Pheidole defecta of Guatemala (known only from the major caste and placed tentatively in the pilifera group), differing in the shape of promesonotal and propodeal spine, sculpturing, and color.

MEASUREMENTS (mm) Holotype major: HW 0.80, HL 0.78, SL 0.50, EL 0.12, PW 0.34. Paratype minor: HW 0.48, HL 0.54, SL 0.54, EL 0.10, PW 0.32.

COLOR Major: color medium yellow, except for a light brown “mask” as depicted in the figure; the intensity and shape of the mask varies considerably among the major workers in the type series.

Minor: concolorous medium yellow.



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

Type Material
- as reported in Wilson (2003)

Type Locality Information
COSTA RICA: La Selva Biological Station, near Puerto Viejo, Heredia (Bert Hölldobler). (Wilson 2003)

Etymology
Compound Greek and Latin (“like nasute”), referring to resemblance of the major to a Nasutitermes soldier. (Wilson 2003)

Additional References
[[Media:Holldobler & Wilson 1992.pdf|Hölldobler, B.; Wilson, E. O. 1992. Pheidole nasutoides, a new species of Costa Rican ant that apparently mimics termites. Psyche (Camb.) 99: 15-22 PDF]]

Text and images from this publication used by permission of the author.