Pheidole lutea species group

Based on Salata & Fisher, 2020.

Species
Pheidole lutea complex Pheidole navoatrensis complex
 * Pheidole lutea
 * Pheidole ranohirensis
 * Pheidole voasara
 * Pheidole navoatrensis
 * Pheidole parviocula
 * Pheidole typhlos

Species Identification

 * Key to Pheidole lutea species group

Pheidole lutea species complex

Major workers of this complex can be easily distinguished based on a combination of the following characters: head, in full-face view, oval (but not elongate) and in lateral view sub-oval, lacking smooth patches and predominately covered with longitudinal rugae; minute to small propodeal spines; gaster never distinctly shagreened, and bright body colouration. Minor workers can be distinguished based on smooth sculpture of head and mesosoma, with few additional arcuate rugae on vertex and transverse rugulae on mesosoma, moderately short scape, and yellow body.

Pheidole navoatrensis species complex

Major workers of this complex can be easily distinguished from others based on elongate head capsule, strongly reduced sculpture of head and mesosoma, strongly reduced or small propodeal spines, and bright body colouration. Minor workers can be separated from other species based on smooth and shiny head and mesosoma sculpture, short scape, and yellow body colouration.

Group Diagnosis
Major workers Head, in full-face view, oval or elongate, in lateral view sub-oval, ventral and dorsal faces convex or relatively flat; dorsal face not depressed posteriorly; antennal scrobes absent or very indistinct, occipital lobes smooth or with thick, sparse, irregular rugae, sculpture weakening posteriorly; frons with thick rugae, interspaces smooth to rugo-foveolate; genae smooth or with thick, sparse, irregular rugae; promesonotum relatively low to high, and arched; propodeal spines absent, weakly developed, and lobe-like or small and short, triangular; mesosoma surface with fine, sparse to moderately sparse rugoreticulation (dorsal surface with weaker sculpture) or smooth; body yellow to occasionally bright brown.

Minor workers At least frons, genae, and malar area smooth and shiny, sometimes lateral sides of frons with short, indistinct, longitudinal rugulae; scape short, when laid back, reaching posterior head margin or surpassing the posterior head margin by one-fifth of its length; promesonotum, in lateral view, convex or box-like; mesosoma almost entirely smooth; body yellow.

Pheidole lutea species complex
Major workers Head, in full-face view, oval; sides of the head with moderately dense to dense, long, erect pilosity; antennal scrobes indistinct and not delimited by carinulae; scrobe surface shiny, with sparse, thick, longitudinal to irregular rugae, interspaces smooth, indistinctly rugulose to foveolate; occipital lobes and genae with thick, sparse, irregular rugae, interspaces with indistinct foveolae, sculpture weakening posteriorly; frons with dense, thick, and longitudinal rugae, interspaces smooth to foveolate; promesonotum, in lateral view, short, angular, and relatively high; promesonotal and metanotal grooves absent; propodeal spines minute and indistinct to small, triangular; mesosoma with fine, sparse rugoreticulation and indistinct, sparse foveolae or foveolate with additional sparse and thick rugae on promesonotal dorsum and propodeum, sculpture slightly weakening on dorsum; anepisternum and mesosoma with indistinct sculpture or smooth; gaster smooth to finely shagreened; body orange to yellowish brown.

Minor workers Frons, genae, and malar area smooth and shiny, vertex smooth and with few arcuate, interrupted rugae; scape, when laid back, surpassing the posterior head margin by one-fifth of its length; promesonotum moderately low to high, short, evenly arched; promesonotal and metanotal grooves absent; propodeal spines very small, indistinct, triangular; mesosoma smooth and shiny, only dorsum with few transverse, thick rugulae; body yellow.

Pheidole navoatrensis species complex
Major workers Head, in full-face view, elongate; antennal scrobes absent or very indistinct, occipital lobes smooth, sometimes with indistinct, very sparse, longitudinal to irregular rugoreticulations, sculpture, when present, fading anteriorly; frons with thick, sparse, short and interrupted rugae and smooth interspaces or smooth with few short, thick, longitudinal rugae on the anterior part; genae smooth; promesonotum relatively low to high, and arched; propodeal spines absent, weakly developed, and lobe-like or small and short, triangular; mesosoma surface with fine, sparse to moderately sparse rugoreticulation (dorsal surface with weaker sculpture) or smooth with indistinct and sparse sculpture on lateral sides; gaster smooth; body yellow, orange and occasionally bright brown.

Minor workers Head smooth, only lateral sides of frons with short, indistinct, longitudinal rugulae; scape, when laid back, reaching posterior head margin; promesonotum, in lateral view, convex or box-like; mesosoma sculpture smooth and shiny, and sometimes lateral sides with indistinct, irregular, and sparse rugae; body yellow.

Distribution
Madagascar.

Pheidole lutea species complex: Distributed across dry deciduous forest biome and Sambirano rainforest biome.

Pheidole navoatrensis species complex: Known from central highlands, with P. navoatrensis also extending its range into the dry deciduous biome. Pheidole typhlos is known only from its type locality, the Galoko massif.

Additional Resources

 * Pheidole
 * Madagascar