Pheidole nebulosa

This species inhabits mature wet forest. It appears to be both arboreal and terrestrial, occurring commonly in forest floor leaf litter and in the canopy. Nests are in irregular cavities in dead wood. Wilson (2005) observed that P. nebulosa and two other species of small Pheidole (flavens and bilimeki) frequently prey on oribatid mites in the leaf litter. (Longino 2009)

Identification
Pheidole nebulosa has a highly distinctive feature in the major workers: there is a single large rounded medial tooth on the hypostomal margin and no inner hypostomal teeth. All other Central American Pheidole in the same size range and with similar sculptural features have inner hypostomal teeth.

Also see the description in the nomenclature section.

Distribution
Mexico to Costa Rica.

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica, Guatemala, Honduras, Mexico, Nicaragua.

Worker
Minor

Nomenclature

 *  nebulosa. Pheidole nebulosa Wilson, 2003: 470, figs. (s.w.) COSTA RICA. Senior synonym of scabriventris: Longino, 2009: 57.
 * scabriventris. Pheidole scabriventris Wilson, 2003: 503, figs. (s.w.) MEXICO. Junior synonym of nebulosa: Longino, 2009: 57.

Longino (2009) - The only difference between the types of P. scabriventris and P. nebulosa is color. The former is red brown instead of yellow.

Description
DIAGNOSIS Similar in various traits to Pheidole bilimeki, Pheidole chalca, Pheidole daphne, Pheidole floridana, Pheidole furtiva, Pheidole quercicola, Pheidole specularis and Pheidole stomachosa, differing as follows.

Major: bicolored, mostly yellow (see Color); hypostoma with 2 teeth only; promesonotal profile semicircular; humerus in dorsal-oblique view low and subangulate; all of mesosoma and waist and almost all of dorsal surface of head foveolate and opaque; all of first gastral tergite but the lateral margins shagreened; spaces between eyes and antennal fossae and anterior borders of head rugulose (not rugoreticulate or carinulate).

Minor: humerus in dorsal-oblique view low and subangulate; propodeal spines long, thin, and needle-like; postpetiolar node in side view suppressed; all of head and mesosoma foveolate and opaque, but gaster entirely smooth and shiny, not shagreened.

MEASUREMENTS (mm) Holotype major: HW 0.86, HL 0.92, SL 0.50, EL 0.12, PW 0.44. Paratype minor: HW 0.42, HL 0.46, SL 0.44, EL 0.06, PW 0.28.

COLOR Major: bicolored, with body and appendages medium yellow with light reddish tinge (tending to light “orange”), and with medium brown second to terminal gastral tergites.

Minor: concolorous medium yellow with slight reddish tinge.



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

Type Material
Longino (2009):

Holotype major worker and associated paratype minor worker: Costa Rica, Heredia, La Selva Biological Station, near Puerto Viejo (Cover, Moffett, Tobin) MCZ (examined).

Pheidole scabriventris Holotype major worker and associated paratype minor worker: Mexico, Veracruz, park cañon, 2mi W Fortin, Hway 150, 6-9 Aug 1969 (S. & J. Peck) MCZ (examined).

Etymology
L nebulosa, misty, cloudy, alluding to the general foveolate and shagreened body surface.

References based on Global Ant Biodiversity Informatics

 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * INBio Collection (via Gbif)
 * Longino J. T. 2013. Ants of Nicargua. Consulted on 18 Jan 2013. https://sites.google.com/site/longinollama/reports/ants-of-nicaragua
 * 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., J. Coddington, and R. K. Colwell. 2002. The ant fauna of a tropical rain forest: estimating species richness three different ways. Ecology 83: 689-702.
 * 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/
 * Milks, M.L., J.R. Fuxa, A.R. Richter and E.B. Moser. 2007. Multivariate analyses of the factors affecting the distribution, abundance and social form of Louisiana fire ants, Solenopsis invicta. Insectes Sociaux 54:283-292
 * Ottonetti L., L. Tucci, F. Frizzi, G. Chelazzi, and G. Santini. 2010. Changes in ground-foraging ant assemblages along a disturbance gradient in a tropical agricultural landscape. Ethology Ecology & Evolution 22: 7386.
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
 * Wilson, E.O. 2003. Pheidole in the New World: A Dominant, Hyperdiverse Genus. Harvard University Press