Pheidole nemoralis species group

Based on Salata & Fisher, 2020.

Species
Pheidole bemarivoensis complex Pheidole nemoralis complex
 * Pheidole bemarahaensis
 * Pheidole bemarivoensis
 * Pheidole nemoralis
 * Pheidole ala

Species Identification

 * Key to Pheidole nemoralis species group

Pheidole bemarivoensis species complex

Major workers of this group can be distinguished based on a combination of the following characters: small body size; head in full-face view square and in lateral view sub-oval; foveolate scrobes with additional sparse rugulae; foveolate occipital lobes, with additional sparse, irregular rugae; sculpture weakening posteriorly; indistinctly shagreened gaster and brown to dark brown body. Minor workers can be separated based on small body size, entirely foveolate head and mesosoma; scape, when laid back, surpassing the posterior head margin by one- to two-fifths of its length; long and low promesonotum with relatively steep posterior declivity, and yellow body.

Pheidole nemoralis species complex

Major workers of this complex can be distinguished based on a combination of the following characters: head in full-face and lateral views sub-rectangular; foveolate scrobe surface with sparse, thick, irregular rugae; small and triangular propodeal spines; mesosoma with fine but distinct foveolae or rugo-foveolae, and additional sparse, irregular rugae; bright brown to dark brown body. Minor workers can be separated based on foveolate head with genae smooth or with reduced sculpture and smooth katepisternum, anepisternum, and mesonotum; minute to small propodeal spines, and yellow body.

Group Diagnosis
Major workers Body size small; head in full-face view square or subrectangular, anterior and posterior sides of eyes slightly convex, in lateral view sub-oval or sub-rectangular, dorsal face not depressed or finely depressed posteriorly; antennal scrobes indistinct and not delimited by carinulae; scrobe surface foveolate with sparse, thick, longitudinal to irregular rugae; occipital lobes with indistinct to distinct, sparse, irregular rugae, interspaces smooth to foveolate; frons with dense, thick, and longitudinal rugae, interspaces smooth to rugo-foveolate; promesonotum moderately short, relatively low and convex; promesonotal and metanotal groove absent; propodeal spines small to moderately long, triangular; mesosoma with fine foveolae or rugo-foveolae; gaster smooth or indistinctly shagreened; body bright brown to dark brown.

Minor workers Head foveolate, sometimes with reduced or absent sculpture on genae; scape short, when laid back surpassing the posterior head margin by one to two-fifths of its length; promesonotum low, short or long, slightly convex, with relatively steep posterior declivity or declivity smoothly declining towards propodeum; promesonotal groove absent; mesosoma entirely foveolate or foveolate with smooth notches on its lateral sides; propodeal spines minute to moderately long, triangular; body yellow.

Pheidole bemarivoensis species complex
Major Workers Body size small; head in full-face view square, in lateral view sub-oval, ventral and dorsal faces convex, dorsal face not depressed posteriorly; scrobe foveolate with sparse, thick, longitudinal to irregular rugulae; occipital lobes foveolate, with indistinct, sparse, irregular rugae; sculpture weakening posteriorly; frons with dense, thick, and longitudinal rugae, interspaces smooth to foveolate; propodeal spines small to moderately long; mesosoma with fine foveolae and with additional rugae; gaster indistinctly shagreened; body brown to dark brown.

Minor Workers Head foveolate; scape, when laid back, surpassing the posterior head margin by one to two-fifths of its length; promesonotum low, long, slightly convex, with relatively steep posterior declivity; metanotal groove present; propodeal spines very small or moderately long, triangular; mesosoma foveolate.

Pheidole nemoralis species complex
Major Workers Head in full-face view sub-rectangular, in lateral view sub-rectangular, ventral and dorsal faces relatively convex and dorsal face finely depressed posteriorly; scrobe surface foveolate with sparse, thick, irregular rugae; occipital lobes with indistinct to distinct, sparse, irregular rugae, interspaces sometimes foveolate, and sculpture sometimes weakening posteriorly; frons with dense, thick, and longitudinal rugae, interspaces distinctly to finely foveolate or rugo-foveolate; propodeal spines small; mesosoma with fine but distinct foveolae or rugo-foveolae, and with additional sparse, fine, and irregular rugae; gaster smooth or finely shagreened; body bright brown to dark brown.

Minor Workers Head foveolate; genae with reduced sculpture or smooth; scape, when laid back, surpassing the posterior head margin by one-fifth of its length; promesonotum low, short, slightly convex, with relatively steep posterior declivity or declivity smoothly declining towards propodeum; metanotal groove absent or indistinct; propodeal spines minute to small, triangular; mesosoma foveolate, katepisternum, anepisternum, and mesonotum smooth.

Distribution
Madagascar.

Pheidole bemarivoensis complex: Pheidole bemarahaensis is known only from its type locality (Parc National Tsingy de Bemaraha, Mahajanga) and is sympatric with P. bemarivoensis, which is distributed in lowlands spread between Belo and Ambilobe.

Pheidole nemoralis complex: two sympatric species distributed across the evergreen forest and central highlands biomes.

Additional Resources

 * Pheidole
 * Madagascar