Pheidole ferruginea species group

Based on Salata & Fisher, 2020.

Species
Pheidole ferruginea complex
 * Pheidole ferruginea
 * Pheidole rugocephala
 * Pheidole vohemarensis
 * Pheidole manantenensis

Pheidole longipilosa complex
 * Pheidole longipilosa

Species Identification

 * Key to Pheidole ferruginea species group

Pheidole ferruginea species complex

Major workers of this complex can be distinguished based on a combination of the following characters: head in full-face view cordate, in lateral view oval to sub-oval; antennal scrobes developed and well delimited; never smooth occipital lobes and frons; long propodeal spines; and first gastral tergite shagreened, at least on its basal part. Minor workers can be distinguished based on foveolate head and mesosoma, sometimes with additional longitudinal rugae on frons or promesonotum; moderately long to long propodeal spines; and body yellow to brown.

Pheidole longipilosa species complex

Major workers of this complex can be distinguished based on a combination of the following characters: head in full-face view elongated, in lateral view sub-oval; sides of the head with dense, long, erect pilosity; head sculptured but never with arcuate or transverse rugulae, central part of frons smooth; propodeal spines small to moderately long, triangular, and smooth gaster. Minor workers can be separated based on foveolate head and mesosoma with additional rugae on frons and smooth katepisternum, short and triangular propodeal spines, and yellow body colouration.

Group Diagnosis
Major workers Head in full-face view cordate or sub-oval, widened posteriorly, in lateral view oval to sub-oval, ventral and dorsal faces strongly convex, dorsal face not depressed posteriorly; antennal scrobes developed, well delimited by carinulae (except Pheidole longipilosa); occipital lobes with sparse and irregular rugoreticulation; promesonotum short, angular, and low to high; promesonotal and metanotal grooves absent; propodeal spines moderately long to long, with base wide or narrow; mesosoma predominately sculptured sometimes with smooth notches; first gastral tergite smooth or shagreened, at least on its basal part; body bright brown to brown.

Minor workers Whole head foveolate, sometimes with additional longitudinal rugae on frons; scape, when laid back, surpassing posterior head margin by one- to two-fifths of its length; promesonotum box-like or convex; propodeal spines short, moderately long or very long; promesonotal and metanotal grooves absent or present; mesosoma predominately foveolate, sometimes with additional rugae on mesosomal dorsum; body yellow to brown.

Pheidole ferruginea species complex
Major workers Head in full-face view cordate, widened posteriorly; antennal scrobes developed, well delimited by carinulae; occipital lobes with sparse and thick rugoreticulation or foveolae, with additional thick, sparse, irregular rugae; frons with sparse, thick, and longitudinal to irregular rugae, interspaces smooth, or with fine rugulae or superficially foveolate; promesonotum short, angular, and low to moderately high; propodeal spines long, with base wide or narrow; mesosoma with thick and sparse to dense rugoreticulation, sometimes sculpture weakening on dorsum, or foveolate, with additional sparse to dense rugoreticulation; first gastral tergite shagreened, at least on its basal part; body reddish brown to brown.

Minor workers Scape, when laid back, surpassing posterior head margin by one- to two-fifths of its length; promesonotum box-like or convex; propodeal spines moderately long to very long; promesonotal groove absent or present; metanotal groove absent or present; mesosoma foveolate, sometimes with additional rugae on mesosomal dorsum; sometimes katepisternum smooth; body yellow to brown.

Pheidole longipilosa species complex
Major Workers Head in full-face view sub-oval; sides of head with dense, very long, erect pilosity; antennal scrobes indistinct and not delimited by carinulae; occipital lobes with thick, irregular rugae, interspaces with distinct, irregular rugulae; genae shiny, with dense and thin, irregular rugulae, central part with smooth notch; promesonotum relatively high and arched; propodeal spines small to moderately long, triangular; promesonotum foveolate with additional indistinct, sparsely rugoreticulate, sometimes sculpture fading on dorsal surface and lower parts of lateral sides; gaster smooth; body reddish brown to bright brown.

Minor Workers Scape, when laid back, surpassing the posterior head margin by one-fifth of its length; promesonotum low, convex, short; promesonotal and metanotal grooves absent; propodeal spines short, triangular; mesosoma foveolate; katepisternum smooth; anepisternum and mesonotum with fading sculpture and sometimes smooth; body yellow.

Distribution
Madagascar.

Pheidole ferruginea species complex (P. ferruginea, P. rugocephala, P. vohemarensis, and P. manantenensis): Pheidole ferruginea is relatively common across the evergreen forest biome. It is sympatric with the remaining three members of the complex. The ranges of P. rugocephala, P. vohemarensis , and P. manantenensis are predominately limited to the Antsiranana prefecture. In the evergreen forest biome, Pheidole rugocephala occurs between Toamasina and Andapa and P. vohemarensis inhabits an area between Ambinaelo and Antsirabe. Pheidole vohemarensis is known from an area spread between Andapa and Antisianana that is predominately dry deciduous forest biome.

Pheidole longipilosa, the lone member of its eponymous species-complex, is known from Forêt Classée d’Analavelona and Parc National d’Isalo in the Toliara prefecture.

Additional Resources

 * Pheidole
 * Madagascar