Pheidole petax species group

Based on Salata & Fisher, 2020.

Species
Pheidole ankerana complex Pheidole boribora complex Pheidole brevipilosa complex Pheidole mavesatra complex Pheidole petax complex
 * Pheidole ankerana
 * Pheidole vatovavensis
 * Pheidole boribora
 * Pheidole miramila
 * Pheidole brevipilosa
 * Pheidole glabra
 * Pheidole mavesatra
 * Pheidole goavana
 * Pheidole petax

Species Identification

 * Key to Pheidole petax species group

Pheidole ankerana species complex

Major workers of this complex can be distinguished based on a combination of the following characters: head in full-face view rectangular, in lateral view sub-rectangular; occipital lobes with thick, sparse, irregular rugae with at least partially smooth interspaces; inner and outer teeth closely spaced and connected by concavity; moderately long propodeal spines; sculpture of mesosoma weakening on dorsum; smooth gaster and yellowish to reddish brown body colouration. Minor workers have foveolate head and mesosoma, sometimes with additional thin rugae, smooth katepisternum, and yellow body.

Pheidole boribora species complex

Major workers of this complex can be distinguished based on a combination of the following characters: head in full-face view oval, in lateral view sub-rectangular; occipital lobes with thick, sparse, irregular rugae, interspaces smooth to finely foveolate; mesosoma predominately with very sparse, transverse to irregular, thin rugae; finely shagreened gaster and yellowish to reddish brown body. Minor workers can be separated based on the following characters: foveolate head and mesosoma, but sculpture of mesosoma strongly reduced to absent on its lateral sides and yellow body.

Pheidole brevipilosa species complex

Major workers of this complex can be distinguished based on a combination of the following characters: head in full-face view square and in lateral view sub-rectangular; occipital lobes with thick and irregular rugae with smooth or superficially rugulae interspaces; frons with thick and longitudinal rugae with smooth to finely rugo-foveolate interspaces; moderately long propodeal spines, with base slightly wider than top; katepisternum, pronotum, and propodeum smooth or with reduced sculpture; finely shagreened first gastral tergite; and brownish black to black body. Minor workers can be separated based on the following characters: head foveolate with few additional, indistinct, longitudinal rugae on frons and malar area; genae and sometimes frons smooth or with reduced sculpture; very short and triangular propodeal spines; never entirely foveolate mesosoma; and dark brown body colouration.

Pheidole mavesatra species complex

Major workers of this complex can be distinguished based on a combination of the following characters: head in full-face view rectangular and in lateral view sub-rectangular; foveolate antennal scrobes with additional thin, longitudinal rugae; occipital lobes with thick and irregular rugae and foveolate interspaces, foveolae fading posteriorly; moderately long and triangular propodeal spines; finely shagreened gaster and brown to brownish black body. Minor workers can be separated based on: foveolate head and mesosoma with reduced sculpture on genae and katepisternum; low and long promesonotum, with steep posterior declivity, and yellow body.

Pheidole petax species complex

Major workers of this complex can be distinguished based on a compilation of the following characters: head in full-face view rectangular and in lateral view sub-rectangular; sides of the head with sparse, short, and decumbent pilosity; occipital lobes with thick and irregular rugae with smooth interspaces; frons with thick and longitudinal rugae and smooth to finely foveolate interspaces; small propodeal spines with wide base; smooth katepisternum; shagreened first gastral tergite, and brown to dark brown body. Minor workers can be separated based on foveolate head and mesosoma, with smooth katepisternum and genae with smooth notches; promesonotum with relatively steep posterior declivity; very short propodeal spines and yellowish-brown body.

Group Diagnosis
Major workers Head in full-face view rectangular or square (except P. boribora), anterior and posterior of eyes relatively straight, in lateral view sub-rectangular, ventral and dorsal faces finely convex or flat and dorsal face finely depressed posteriorly; antennal scrobes shallowly impressed and not delimited (except P. ankerana complex); occipital lobes with thick, sparse, irregular rugae; frons with thick, sparse to moderately sparse, longitudinal rugae; antennal scrobes with finely foveolate interspaces (except P. glabra sp. nov. and P. ankerana complex); promesonotum relatively low and angular; propodeal spines small to moderately long, with wide base; body yellowish brown to black.

Minor workers Head foveolate, sometimes with few additional rugae; genae and frons sometimes with smooth notches; scape short, when laid back, surpassing the posterior head margin by one- to two-fifths of its length; promesonotum slightly convex, with relatively steep posterior declivity; mesosoma foveolate, sometimes with smooth notches on the lateral sides; propodeal spines minute to relatively long, triangular or narrow; body yellow to yellowish brown (except P. brevipilosa complex).

Pheidole ankerana species complex
Major Workers Head in full-face view rectangular, in lateral view sub-rectangular, ventral and dorsal faces finely convex; sides of the head with moderately dense to dense, long, suberect to erect pilosity; scrobe surface shiny, with dense, thick, and irregular rugoreticulate or foveolate with thick, longitudinal rugae; occipital lobes and frons with interspaces smooth or finely rugulose; inner and outer teeth closely spaced and connected by concavity; promesonotal and metanotal grooves absent; propodeal spines moderately long, triangular; mesosoma with fine to thin, dense rugoreticulation and sometimes additional foveolae, sculpture weakening on dorsum, katepisternum smooth; gaster smooth; body yellowish to reddish brown.

Minor Workers Whole head foveolate, sometimes with additional thin, sparse rugae; scape, when laid back, surpassing the posterior head margin by one to two-fifths of its length; promesonotum low, short, slightly convex; propodeal spines minute or relatively long, triangular; mesosoma foveolate, sometimes with additional thin, sparse rugae, katepisternum smooth.

Pheidole boribora species complex
Major Workers Head in full-face view oval, in lateral view sub-rectangular, ventral and dorsal faces finely convex; sides of the head with sparse to moderately dense, short or long, erect pilosity; occipital lobes with interspaces smooth to finely foveolate; frons with interspaces smooth to finely foveolate; lateral sides of head with additional thin, sparse, longitudinal rugae or with thin, dense irregular rugoreticulation; promesonotal groove absent; metanotal groove absent or indistinct; propodeal spines small or moderately long, triangular; mesosoma with very sparse, transverse to irregular thin rugae, sometimes pronotum and propodeum with additional indistinct and sparse foveolae; gaster finely shagreened; body yellowish to reddish brown.

Minor Workers Head foveolate; scape, when laid back, surpassing the posterior head margin by two-fifths of its length; promesonotum low, short, slightly convex; mesosoma foveolate, but mesonotum, anepisternum, katepisternum and lateral surfaces of propodeum smooth.

Pheidole brevipilosa species complex
Major Workers Head in full-face view square, anterior and posterior of eyes relatively straight, in lateral view sub-rectangular; ventral and dorsal faces relatively flat; occipital lobes with interspaces smooth or superficially rugulose; frons with interspaces smooth to finely rugo-foveolate; promesonotal groove absent; metanotal groove absent or indistinct; propodeal spines moderately long, with base slightly wider than top; mesosoma with fine and sparse to dense rugoreticulation, katepisternum smooth, sometimes pronotum and propodeum partially smooth; first gastral tergite finely shagreened; body brownish black to black.

Minor Workers Head foveolate, frons and malar area with few additional, indistinct, longitudinal rugae, genae and sometimes frons with weaker sculpture or smooth; scape, when laid back, surpassing the posterior head margin by one-fifth of its length; promesonotum low, slightly convex, with relatively steep posterior declivity; promesonotal groove absent; metanotal groove indistinct; propodeal spines very short, triangular; mesosoma foveolate; katepisternum smooth and promesonotal dorsum with additional sparse, irregular rugae or katepisternum, anepisternum, and parts of propodeum and pronotum smooth.

Pheidole mavesatra species complex
Major Workers Head in full-face view rectangular, anterior of eyes relatively straight, posterior of eyes slightly convex; in lateral view sub-rectangular; ventral and dorsal faces finely convex or relatively flat; scrobe surface shiny with sparse, thin, longitudinal rugae; occipital lobes with interspaces foveolae; frons with interspaces superficially foveolate; genae shiny, with distinct and thin rugulae; promesonotal groove absent; metanotal groove absent or indistinct; propodeal spines moderately long, triangular, with very wide base; mesosoma foveolate with additional thick, sparse, and irregular rugae on promesonotum and propodeum, and katepisternum smooth or mesosoma with thin, moderately dense to dense rugoreticulation with foveolate interspaces; gaster finely shagreened; body brown to brownish black.

Minor Workers Head foveolate and genae with reduced sculpture; scape, when laid back, surpassing the posterior head margin by one-fifth of its length; promesonotum low, long, relatively flat or slightly convex, with steep posterior declivity; promesonotal groove absent; metanotal groove indistinct; propodeal spines moderately long to long, triangular or narrow; mesosoma foveolate; katepisternum at least partly, and sometimes mesosoma, smooth.

Pheidole petax species complex
Major Workers Head in full-face view rectangular, anterior and posterior of eyes relatively straight, in lateral view sub-rectangular, ventral and dorsal faces finely convex; sides of the head with sparse, short, decumbent pilosity; occipital lobes with interspaces smooth; frons with interspaces smooth to finely foveolate; antennal scrobes with dense, fine rugulae, and sometimes with additional sparse and fine, longitudinal rugae; promesonotal and metanotal grooves absent; propodeal spines small, with wide base; pronotum with sparse, irregular, thin rugae, interspaces smooth to finely foveolate; katepisternum smooth; first gastral tergite shagreened; body brown to dark brown.

Minor Workers Head foveolate, genae with smooth notches; scape, when laid back, surpassing the posterior head margin by two-fifths of its length; promesonotum slightly convex, with relatively steep posterior declivity; mesosoma foveolate, katepisternum and, sometimes, lateral sides of propodeum smooth; promesonotal groove absent; metanotal groove indistinct; propodeal spines very short and triangular.

Distribution
Madagascar.

Pheidole ankerana complex: Pheidole ankerana is known from two localities, Ankerana and Parc National de Zahamena, Toamasina. Pheidole vatovavensis is so far recorded only from Forêt Classée Vatovavy, Fianarantsoa.

Pheidole boribora complex: Pheidole boribora was discovered in Parc National d’Andohahela, Toliara and P. miramila in Ambalavao, Fianarantsoa. Both species are known only from their type localities.

Pheidole brevipilosa complex: Pheidole brevipilosa is known from two localities, Réserve Spéciale Marotandrano, Mahajanga and Forêt de Petriky, Toliara. Pheidole glabra is known from the area surrounding Tolagnaro, Toliara.

Pheidole mavesatra complex: Distributed in the northern part of the island. Pheidole mavesatra is only known from its type locality (Tampolo, Toamasina) and P. goavana is distributed exclusively in Antsiranana prefecture, in an area spread between Ambalabe and Antisiranana.

Pheidole petax, the only member of its complex, is common across the evergreen forests and central highlands. It is sympatric with all members of the group.

Additional Resources

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