Pheidole longispinosa species group

Based on Salata & Fisher, 2020.

Species
Pheidole longispinosa complex Pheidole scabrata complex
 * Pheidole longispinosa
 * Pheidole mahaboensis
 * Pheidole praegrandis
 * Pheidole maizina
 * Pheidole scabrata

Species Identification

 * Key to Pheidole longispinosa species group

Pheidole longispinosa species complex

Species of this complex are characterized by a large body size, both in minor and major workers. Major workers can be distinguished by a combination of the following characters: head, in full-face view, trapezoid and widened posteriorly, in lateral view sub-oval; sides of the head with pilosity absent or very sparse and short; predominantly smooth occipital lobes; very long and massive propodeal spines and brown to black body colouration. Minor workers can be distinguished by smooth or finely rugulose head with smooth patches; long scape (surpassing posterior head margin by more than half of its length); very long and massive propodeal spines; smooth or indistinctly rugulose mesosoma, and long peduncle of petiole.

Pheidole scabrata species complex

Species of this complex are characterized by a large body, both in minor and major workers. Major workers can be distinguished by a combination of the following characters: head, in full-face view, trapezoid and widened posteriorly, in lateral view sub-oval; sides of the head with sparse, relatively long, erect pilosity, occipital lobes predominantly smooth; frons with rugae directed outward, and very long, massive propodeal spines. Minor workers can be distinguished based on long scape (surpassing posterior head margin by one-third of its length); very long propodeal spines; mesosoma with dense rugoreticulation, and long and thin peduncle of petiole.

Group Diagnosis
Major workers Large species; head, in full-face view, trapezoid, widened posteriorly, in lateral view sub-oval, ventral and dorsal faces convex, dorsal face not depressed posteriorly; antennal scrobes absent or indistinct; occipital lobes smooth, at least on the posterior part; genae smooth to finely rugulose; head sculpture weakens posteriorly; promesonotum short, low, and evenly convex; propodeal spines very long; first gastral tergite smooth to shagreened; body brown to black.

Minor workers Head smooth to rugoreticulate, central part of frons usually with smooth notch; scape, when laid back, surpassing posterior head margin by one third or more than half of its length; promesonotum low, long, and slightly convex; promesonotal groove absent or very indistinct; metanotal groove very indistinct; propodeal spines very long; petiole with long and thin peduncle; body brown to black.

Pheidole longispinosa species complex
Major workers Sides of the head with pilosity absent or very sparse, short, and decumbent; antennal scrobes absent or very indistinct; occipital lobes smooth and shiny or partially shagreened; genae smooth or partially superficially rugulose or shagreened; promesonotum low, short, and relatively flat; promesonotal groove absent; metanotal groove absent or distinct; propodeal spines very long; mesosoma shiny and smooth with weak, sparse, and irregular rugae on pronotum and lateral sides of propodeum or rugoreticulate, with weaker sculpture on propodeal dorsum; gaster smooth or first gastral tergite shagreened. Minor workers Scape, when laid back, surpassing posterior head margin by more than half of its length; promesonotal groove absent; metanotal groove indistinct to distinct; mesosoma smooth, indistinctly rugulose or the whole surface finely rugoreticulate.

Pheidole scabrata species complex
Major workers Sides of the head with sparse, relatively long, erect pilosity; antennal scrobes absent; occipital lobes smooth, at least on the posterior part; genae smooth to finely rugulose; centre of frons with longitudinal rugae directed outward posteriorly; inner and outer teeth closely spaced and connected by indistinct concavity; promesonotal groove absent; mesosoma with sparse to relatively dense rugoreticulation, mesosomal dorsum and propodeum with weaker sculpture or smooth patches; first gastral tergite smooth to shagreened.

Minor workers Scape, when laid back, surpassing posterior head margin by one third of its length; promesonotal groove absent or very indistinct; metanotal groove very indistinct; mesosoma with dense rugoreticulation, sometimes dorsum with weaker sculpture, but never smooth.

Distribution
Madagascar.

Pheidole longispinosa species complex: A majority of P. longispinosa records are from the central highlands, with the remainder in dry deciduous biome and evergreen rainforest. Pheidole mahaboensis is distributed across the evergreen rainforest biome and central highlands. In the southern part of its distribution it is sympatric with P. longispinosa. Pheidole praegrandis is known exclusively from the evergreen rainforest biome with its centre of distribution in the northernmost part. In the remaining areas of the biome P. praegrandis is sympatric with P. mahaboensis.

The two species of the Pheidole scabrata species complex occur sympatrically in the northern parts of evergreen forest and central highlands biomes.

Additional Resources

 * Pheidole
 * Pheidole species groups of Madagascar
 * Key to Pheidole species groups of Madagascar
 * Madagascar