Pheidole pallidula (Nylander) - revised

MAJOR MINOR Type location Sicily (Myrmica pallidula, Nylander, 1849: 42, worker; Oecophthora pallidula, Mayr, 1855: 457, soldier, queen & male);
junior synonyms
inquilina (Xenophaenogaster inquilina, Baroni Urbani, 1964b: 50, illustrated, worker; synonymy Bolton, 1987: 291) from Sicily
megacephala (Myrmica megacephala, Losana, 1834: 328, major & minor) from Italy, Piedmont, collected by M Losana
recticeps (Pheidole pallidula Nyl subsp. tristis For, var. recticeps n. var., Forel, 1909e: 391; Menozzi: 1932e, 452, soldier & worker; include the capensis of Emery, 1891: 13, given by Emery, 1915j: 227) from Egypt, collector M. Ed. Wundsam
subdentata (Oecophthora subdentata, Mayr, 1853a: 145, soldier & worker; synonymy by Mayr, 1855: 455) from Austria;
subspecies
obscura (Pheidole pallidula v. n. emeryi, Krausse, 1912a: 169, soldier & worker; replacement name by Santschi, 1936c: 200) from Sardinia.

Nylander's (1849) description is at . Losana (1833) described specimens of "M. [Myrmica] megacephala" referring to "the megacephala of Latreille"; this is at . Mayr's (1853a) description of subdentata is at . Mayr's (1855) descriptions are at and . Roger (1862c: 294) gave a note to clarify the conflicting use of the name Myrmica megacephala by Losana, this is at . Emery (1869b: 19) gave a fuller description, this is at . Bondroit (1918: 165) gave a description of the type form, this is at . Forel's (1909e) description of recticeps, is at . Krausse's (1912a) naming of obscura (as emeryi), is at . Emery (1915j) gave notes and illustrations - see Emery (1919a) gave further notes and illustrations - see this corrected a juxtaposition of images in his review paper (Emery, 1915j). Santschi (1936c) gave a short note, this is at . Finzi (1936) gave a description of recticeps, is at .

Nylander (1842) gave the minor as pale rust; sparse long hairs, long antennae, TL 2 mm, Messina, Sicily. In brief, the description of O. subdentata major by Mayr, 1853a, 1855; Emery, 1869; was TL 4.23 mm; mandibles smooth, with fine points; reddish yellow, hind leg brownish; Austria.

From that, Losana's (1833) Myrmica megacephala almost certainly was Pheidole pallidula He described the ant as nesting in our garden, in Piemonte (Piedmont), in northwest Italy, and described it as a lion-coloured ant. The Losana specimens, both majors and minors had black, or dark, gasters.

Forel's (1909e: 391) brief description of recticeps as a variety of subspecies tristis is odd. The pale colour points to the type form, albeit possibly with a longer more rectangular head.

With a range of fresh specimens we have separated pallidula, with the type from mainly western Mediterranean areas, from two eastern species, Pheidole arenarum and Pheidole orientalis. This moves on from Emery (1915j: 229 ff), who was firm in stating that the type form was not found in Asia. However, following the fashion of the time (stemming from Forel, 1874), Emery clustered the eastern forms under the subspecies arenarum, as noted above this was raised to species by Collingwood (1961a, b) but later was synonymized with pallidula by Atanassov & Dlussky (1992: 123).

We feel justified also in separating off Pheidole tristis as a distinct desert or semi-desert species. As noted above, we feel arenarum occurs from Turkey eastwards and, therefore, doubt that Bernard's (1945) recognition of it from the Sahara was correct (see below).

We are left with the status of recticeps and obscura (emeryi).

André (1886: 383), gave the earliest illustration and in his key noted -
MAJOR - funiculus segments not longer than wide; posterior part of head smooth; postpetiole widened laterally into conical tubercles. Propodeum with small teeth that are not longer than their basal width. Smooth and shiny, with the anterior of the head longitudinally striate, propodeum rugose. Varying from pale yellow, with the head reddish and the gaster blackish, to, red brown with the antennae and legs lighter, the occiput and gaster darker; TL 3.7-4.5 mm.
MINOR - funiculus segments 2-5 transverse, not longer than wide; propodeum with small dentiform tubercles which are wide but extremely short;overall smooth and shiny, genae superficially striate, propdeum punctate-rugose. Variation from pale yellow with the head a little duller and the gaster more or less blackish; to red brown with the antennae and legs lighter and the head and gaster again blackish brown. TL 1.7-2.7 mm.
Distribution - Meridional Europe, western Asia, north of Africa.

That, however, from his distribution list, was a blanket description, especially the note on colour. The illustration obviously differs from the type fawn or "lion-coloured". It appears to be the dar brown colour given for variety emeryi from Sardinia, by Krausse (1912a).

Santschi (1936c) commented that inermis had a paler colour and smaller eyes than the type, the major had more rounded sides to the postpetiole than the type pallidula. As we show inermis is a junior synonym of Pheidole sinaitica. On obscura, he noted the general colour was darker, especially the head and gaster, but the genae and appendages remained light; the postpetiole was the same width as in the type. Finzi's (1936) description of recticeps noted that the major had a longer head and dark patches on the gaster.

After a study of specimens from Morocco, Cagniant (1964) remarked that the sub-species of the authors were not greatly significant as the workers and soldiers are very variable in the same nest but he provided no supporting information. [Cagniant, H. 1964. Étude de quelques fourmis marocaines. Statistique provisoire des Formicidae du Maroc. Bull. Soc. Hist. Nat. Afr. Nord, 53, 83-118]. Earlier, however, Bernard (e.g. Bernard, 1948) had maintained the recognition of subspecies and varieties, listing recticeps from the Saharan oases, such as Fezzan. Previously, after studying the Maora Forest in Morocco, he had separated the ecological requirements of the various forms as - the type pallidula as widespread, often found in houses; the variety tristis as seemingly limited to clay soils and valleys; and, the subspecies arenarum Ruszky as mainly from the dry plateaux and the Sahara (Bernard, 1945).

Bernard (1967: 153, with illustrations) described the minors as TL 1.6-2.6 mm, varying from pale yellow-gold (from very sunny, warm sites) to to brown almost black (from shady sites, around Lyons, etc.), shiny and almost smooth. The majors, TL 3.3-4.9 mm, were similarly coloured to the minors; with the tints varying somewhat with the local microclimate, even in the same site.

With the availability of fresh specimens from Egypt and Spain, the link pages give fresh photographs and descriptions of
Major workers; Minor workers

The images on the majors page show the pale, apparently type form major, with a relatively short ovoid head, from Croatia. That matches Mayr's (1853a) descrtion of Oecophthora subdentata. With the specimens we have from Spain and Egypt, however, the pale major has a longer, more rectangular head. From Sant Celoni, Barcelona, Xavier Espadaler sent us a light major and dark majors that appear to match the André illustration, i.e. probably the obscura form. Apart from the colour the only obvious difference from the pale major is the length of the head. The scape length and scape index are similar; also, the arrangement of hypostomal teeth is the same.

Thus, our present conclusion, has to be that Bernard (1967) and, at least in part, Cagniant (1964) were right in their assertions of variability.

Bernard (1967) gave good illustrations of the sexuals.