The Ants of Africa
SUBFAMILY MYRMICINAE - Genus Pheidole
provisional key to major workers of all African species - Section 6
Genus Pheidole Introduction
return to key Alitrunk with low or no mesonotal welt
-- Hypostomal teeth
(non-type)
35
Head distinctly longer than wide fully striate and parallel-sided Section 7
-- Head length and width near equal but with short frontal carinae, no scrobes and short scapes (SI max 50) 36
--
Head length and width near equal but with distinct long frontal carinae, shallow scrobes and most with long scapes (SI ca 60-65) Section 8

HL near equal to HW --
36 Head fully striate and parallel-sided; postpetiole squamiform (with anterior ventral process, smaller process on anterior ventral petiole); funiculi filiform 37
-- Head never fully striate and with at least weakly convex sides 38
- Major head fully striate and parallel-sided --
37 {Pheidole saxicola major}
TL ca 8.0 mm, HL ca 3.0, HW ca 2.8, SL ca 1.4, PW 1.33; CI 89, SI 50; dark ferruginous red, extremities darker brown to blackish
.
. {Pheidole saxicola minor}
TL 2.7 to 3 mm, HL 0.79, HW 0.71, SL 0.86, PW 0.45; CI 92, SI 120; head subrectangular, as broad in front as behind, with straight, subparallel sides, rounded posterior corners and nearly straight posterior border; eyes convex, at the middle of the sides; mandibles rather large, deflected at the tip, with denticulate apical borders and two larger terminal teeth; clypeus distinctly carinate, with the anterior border very feebly sinuate in the middle; antennal scapes extending one-third their length beyond the posterior corners of the head; promesonotum profile convex; propodeal dorsum a little longer than the declivity; spines slender, acute, erect, about half as long as their interval; petiole slender, twice as long as broad, scarcely broader behind than in front, with the sides only very faintly concave; node transverse, its border distinctly notched in the middle; postpetiole twice as broad as the petiole, as long as broad, subglobose, not toothed on the ventral side; gaster about as large as the head; shining; mandibles subopaque, finely striatopunctate; sides of head delicately longitudinally rugulose and reticulate; alitrunk, petiole, and postpetiole finely and densely punctate, opaque; upper surface of pronotum and postpetiole smooth and shining; gaster and legs shining, sparsely punctate; erect hairs fine yellowish; scapes, like the legs, with numerous oblique hairs; brown; head darker above and behind; gaster, except the edges of the segments, middle portions of legs, fore coxae, and usually also the pronotum and upper surfaces of the petiolar nodes, darker than the posterior portion of the thorax.
Zare - saxicola
-- {Pheidole maufei}
TL 4.0-4.3 mm, HL 1.47, HW 1.25, SL 1.0, PW 0.56; CI 84, SI 80; head relatively long & narrow, sides near straight; with relatively long narrow propodeal spines; head and alitrunk dull with fairly close reticulation, on head latter overlaid with coarse rugose reticulation; pilosity yellowish, pubescence sparse to nil on body, long oblique on appendages; dark yellowish-brown to brownish-red
.
. {Pheidole maufei minor}
TL 2.6-3.0 mm, HL 0.69, HW 0.54, SL 1.04, PW 0.38; CI 76, SI 188; postpetiole with distinctive pyriform shape; head and alitrunk dull with fairly close reticulation, on head latter overlaid with coarse rugose reticulation, middle of vertex shiny; pilosity yellowish, pubescence sparse to nil on body, long oblique on appendages; dark yellowish-brown to brownish-red
Major and minor seemingly unique so key placement by default
Zimbabwe - maufei
. Major head never fully striate and not parallel-sided .
38 {Pheidole picata major}
TL ca 3.5 mm; head shape distinct - West African & Congo Basin records dubious
.
. {Pheidole picata minor}
TL ca 2,7 mm, HL 0.60, HW 0.49, SL 0.65, PW 0.32; CI 82, SI 119; small red brown with evenly ovoid head and the minute propodeal spines
Madagascar - picata
--
Major head otherwise
39

39 {Ph costauriensis pedicel}{Pheidole crassinoda face}
Major head cordiform (heart-shaped); propodeal spines upturned, stout and blunt; postpetiole profile globular, in dorsal view wider than long, hexagonal with rounded lateral prominences
40
-- {Ph megacephala pedicel}{Pheidole megacephala face & pedicel}
Head in full-face view with only moderately convex sides; mandibles relatively slender, with at most reduced teeth or denticles; funiculus segments quadrate; postpetiole trapezoidal but without elongated lateral prominences, ventrally concave, giving profile a somewhat globular appearance
43
-  Major head cordiform --
40 Colour dark brown to black; major head CI ca 100
41
-- Colour lighter; major head CI ca 105 (wider than long)
42
41 pheidole melancholica
TL 4.3 mm, HL 1.55, HW 1.5, SL 0.75, PW 0.70; CI 97, SI 50; posterior of head with shiny areas on vertex; black or very dark brown with anterior of head and sides of mesonotum red-brown
. Pheidole melancholica
. pheidole melancholica minor
TL 3 mm, HL 0.67, HW 0.59, SL 0.67, PW 0.39; CI 92, SI 110; head longer and more rounded posteriorly; head polished and shiny with little or no sculpturation; dorsum of alitrunk more strongly sculptured; propodeum longer with stronger spines; erect pilosity quite sparse; black or very dark brown, appendages and mandibles brownish.
West Africa & Congo Basin - melancholica
-- {Pheidole aurivillii major}
TL 4.6-5.0 mm, HL 1.44, HW 1.44, SL 0.88, PW 0.64; CI 100, SI 61; occipitum matt with rugulo-reticulation; dorsum of propodeum a third longer than wide; major and minor brown with reddish appendages
. aurivilli
. {Pheidole aurivillii minor}
TL ca 4.0 mm, HL 0.75, HW 0.66, SL 0.88, PW 0.44; CI 88, SI 124; scapes surpass occiput by about two-fifths their length; funiculus segments generally longer than wide; whole of body and tibiae with long pilosity; head with noticeable sculpturation; brown with reddish appendages.
West Africa & Congo Basin - aurivillii
- Colour brown or lighter --
42 {Pheidole rotundata major}
TL 5.8-6.2 mm, HL 1.89, HW 2.0, SL 0.67, PW 0.95; CI 109, SI 43; head widest in posterior fourth
. rotundata
. {Pheidole rotundata minor}
TL 3.0-3.2 mm, HL 0.68, HW 0.59, SL 0.65, PW 0.38; CI 90, SI 110; like punctulata but darker & a little larger; sides of head more strongly striated, frontal area more wider and more angular behind; pronotum with transverse raised dark area; propodeum and sides of mesonotum more strongly reticulate; generally brownish to reddish-brown
Southern & eastern Africa - rotundata
-- {Pheidole impressifrons major}
Type TL ca 4.7 mm, HL 1.47, HW 1.53, SL 0.70, PW 0.77; CI 104, SI 46
West African TL < 5.0 mm, proportions similar; colour brown to testaceous, appendages not significantly different
. impressifrons
--
{Pheidole impressifrons minor}
TL 2.43 mm, HL 0.68, HW 0.62, SL 0.72, PW 0.39; CI 81, SI 123; alitrunk almost all over spiculate, fainter on the dorsal and lateral pronotum;.red-brown, gaster darker but seemingly with diostinctive pale patches (also on major), appendages lighter.
Nigeria & Cameroun (atrocior form) - impressifrons
-- Pheidole irritans
Minor only known - original description inadequate
TL 2.7 mm vs punctulata 3.0 mm; HW 0.6 vs 0.67; HL 0.62 vs 0.71; PW 0.35 vs 0.41. Postpetiole L = W; punctulata L < W; CI 89 vs 89; SI 118 vs 107
South Africa - irritans
-- {short description of image}TL 4.2-4.5, type ca 5.0 mm, HL 1.57, HW 1.64, SL 0.79, PW 0.79; CI 106, SI  48; in profile anterior of head deeper than posterior; promesonotum with very convex profile; propodeal teeth small directed backwards and upwards; pilosity sparse of long yellowish semi-erect hairs; mandibles and posterior of head very shiny, rest less so due to reticulo-striation; dark reddish-brown to light brownish-red, head always darker than alitrunk;
punctulata
. {Pheidole punctulata minor}
TL 2.7-3.0 mm, HL 0.74, HW 0.68, SL 0.74, PW 0.40; CI 92, SI 120; mostly smooth and relatively shiny, propodeum dull and reticulate; variable brown to yellowish-brown
Pan-African - punctulata
return to key Head in full-face view with only moderately convex sides
--
43 {Ph species B alitrunk profile}
TL < 3.4 mm; alitrunk profile smoothly domed, as is propodeal profile, propodeal spines reduced to sharp denticles
44
-- TL > 3.4 mm 46
- Alitrunk profile smoothly domed, as is propodeal profile, propodeal spines reduced to sharp denticles --
44 Scapes and frontal carinae reaching beyond midpoint of face 45

Pheidole crinensis
Frontal carinae reaching just short of the midpoint of the head; scapes distinctly curved; alitrunk with only a low transverse welt; propodeal spines short and acute; postpetiole width and length about the same; erect hairs moderately abundant; head only faintly spiculate in the soldier but with fine longitudinal carinae or rugulation on most of the anterior half; colour orange, gaster very dark brown. TL 2.89 mm, HL 1.18, HW 0.93, CI 79, SL 0.50, SI 54, PW 0.44
.


Pheidole crinensis .
Pheidole crinensis
. {Pheidole crinensis minor}
TL 1.9 mm, HL 0.47, HW 0.42, SL 0.47, PW 0.26; CI 90, SI 112; dorsum of head and entire alitrunk densely spiculate; erect hairs moderately abundant; orange, gaster very dark brown.
West Africa - new species - crinensis
- Frontal carinae reaching at least mid-point of head - postpetiole from above laterally ovoid with sharp to slightly produces apices
--
45 {short description of image}
TL 3.2-3.4 mm, HL 1.10, HW 1.10, SL 0.60, PW 0.46; CI 100, SI 55; head with quite strongly scalloped occipitum, sides convex, frontal notch deep and contiguous with occipital groove, clypeus without a median carina; frontal carina very divergent and as wide apart as long, hardly reaching mid-point of face, scape reaches posterior third of head; pronotum with angular sides, propodeum with dorsum and declivity strongly bordered; head mostly smooth and shiny; body with long erect hairs, irregularly spaced but abundant; red-brown, gaster darker
. decarinata
. Pheidole decarinata minor
TL 2.0-2.4 mm, HL 0.54, HW 0.48, SL 0.56, PW 0.34; CI 86, SI 115; head rectangular slightly longer than wide, posterior angles rounded, occipital border straight and weakly impressed (?); eyes set at mid-length and about one-quarter the length of the head; scape surpasses occiput by about one-fifth its length, segments 4-6 of funiculus wider than long, club with apical segment as long as two preceding together; promesonotum smoothly arcuate; propodeum with rectangular dorsum, longer than wide, almost flat and sub-bordered.angles dentate; head, pedicel and gaster, blackish brown; alitrunk and appendages pale reddish brown
Sahel zone - decarinata
--
pheidole scabriucscul minor
Major unknown; minor TL
Tanzania  or Kenya - scabriuscula
return to key TL > 3.3 mm

--
46 {Pheidole megacephala face}
Head with only shallow occipital scalloping; in profile occiput somewhat flattened
48
-- {Pheidole pallidula}
Head with deep occipital scalloping; in profile occiput smoothly convex
47

47 Pheidole kitschneri major
TL ca 3.5 mm, HL 1.08, HW 1.00, SL 0.53, PW 0.38; CI 96, SI 54; frontal carinae short and not forming scrobes, scape not reaching posterior third of head; promesonotum smoothly convex without any impression or welt, truncate behind and margined on each side; sculpturation limited to anterior striations on head and a few striations and reticulations on lateral propodeum (minor similar); erect pilosity yellowish sparse on body and absent from tibiae and scapes; brownish-yellow, legs and antennae dirty yellow
.
. Pheidole kitschneri minor
TL 2.5 mm, HL 0.56, HW 0.53, SL 0.57, PW 0.32; CI 92, SI 114; head oval-rectangular, mandibles dentate, striate near the base; clypeus without a carina, feebly emarginate; mesonotum with two small ridges behind; propodeum subdentate; sculpturation limited to anterior striations on head and a few striations and reticulations on lateral propodeum; erect pilosity yellowish sparse on body and absent from tibiae and scapes; brownish-yellow, legs and antennae dirty yellow
South Africa - kitschneri
-- {Pheidole philippi}
TL 3.5-3.8 mm HL 1.09, HW 1.09, SL 0.54, PW 0.50; CI 100, SI 50; clypeus without a distinct median carina, striations on front of head extending back to mid-point; light chestnut brown
.
. {Pheidole philippi minor}
TL 1.8-2.0 mm; propodeal spines minute; pale greyish yellow, extremities more brown, gaster more brown (note specimen has a damaged head, colour suggests it is a callow)
Ethiopia - philippi
-- {Pheidole albidula}
TL 4.0-4.5 mm; HL 1.44, HW 1.56, SL 0.78, PW 0.67; CI 103, SI 50; uniquely with posterior border of basal two segments of gaster having a row of triangular depressed tubercles, each giving rise to a long hair; sides of head more convex than megacephala and occiput more deeply scalloped, frontal carinae slightly longer than the scape and with weak scrobe; head with frontal striations reaching three-fifths point of face, most of alitrunk and pedicel finely reticulo-punctate, some transverse irregular rugae on pronotal dorsum; most of body pale rust yellow, head and scape darker, posterior of gaster and most of legs whitish
. albidula
. {Pheidole albidula minor}
TL ca 3 mm, HL 0.67, HW 0.60, SL 0.86, PW 0.34; CI 85, SI 165; less elongated; the illustrated specimens were associated with majors and are darker than the type description of generally very pale; most of body pale rust yellow, head and scape darker, posterior of gaster and most of legs whitish
Type: TL ca 2.7 mm, HL 0.67, HW 0.57, SL ?, PW 0.32; CI 85, SI ca 130
Cameroun & Zare - albidula
-- Border of two basal segments of gaster without tubercles; head widest at about two-thirds of length 60
-- Pheidole escherichii
TL 4.5- 5.0 mm; HL 1.78, HW 1.72, SL 1.17, PW 0.62; CI 95, SI 61; head with distinctive trapezoidal shape in full face view; head with distinctive reticulate sculpturation; scapes reaching hind-third of head; alitrunk narrow and slender; proportions of head and alitrunk like in pallidula and sinaitica; propodeal teeth small; postpetiole twice as wide as petiole, laterally blunt; pilosity as in caffra; mostly matt and somewhat punctate; brownish-red, appendages brown, antennae dull yellow; related to aurivilli
. escherichii
. Pheidole escherichii minor

TL 2.5-2.8 mm, HL 0.72, HW 0.66, SL 0.81, PW 0.39; CI 89, SI 132; head a long oval longer than wide; antennal insertions with a distinct narrow margin; scapes surpass occiput by about two-fifths their length; narrow nuchal collar present; mesonotum with two transverse ridges; brown-yellow, head and hindleg brown, gaster darker; somewhat similar to aurivilli
Ethiopia - escherichii
57 {Pheidole squalida}
TL 3.5 mm; HL 1.08, HW 1.04, SL 0.60, PW 0.32; CI 96, SI 56, OI 12; head with quite strong longitudinal striations reaching the occiput; other than striations head, like most of body smooth and shiny, anterior pronotum, sides of propodeum and pedicel superficially reticulo-punctate; whole of body with long fawn hairs; brown yellow, centre of head and apical border of mandibles brown, anterior half of gaster pale yellow rest brown black
REVISE
. Pheidole squalida
. {Pheidole squalida minor}
TL 2.2 mm, HL 0.54, HW 0.47, SL 0.59, PW 0.32; CI 88, SI 115; head ovoid, semi-circular occiput; front area an isoceles triangle extending quite far back between the frontal carinae; eyes set about the mid-point; scape surpassing occiput by about one-fifth its length; promesonotum profile a low regular curve, from above lozenge-shaped with strongly rounded sides; propodeum dorsum flat with anteriorly oblique slope out of the metanotal groove, declivity concave only one-quarter the length of the dorsum, spines as long as two-thirds their interval and often slightly curved anteriorly; mesonotum punctuate as in a powder; abundant long fine pilosity; clear brownish yellow, head darker, mandibles antennae and legs yellow; gaster dirty yellow in front passing to brownish-black behind
REVISE
West Africa & Congo Basin - squalida
-- {Pheidole tristis
TL 4.0-4.5 mm; HL 1.44, HW 1.44, SL 0.72, PW 0.54; CI 100, SI 50-55, OI 12; frontal carinae reaching the mid-point of the face and weakly divergent; mandibles quite large and heavy but with a thin inner, masticatory margin; two basal teeth and two sharp apical teeth; sculptured basally with rugae but dorsally with fine striations and distinctive minute hair pits giving rise to an abundance of short, thickish decumbent hairs; propodeum dorsum with sharp lateral margins and a distinct longitudinal groove which widens from front to back;dark red-brown, with the gaster and mandibles darker
. cicatricosa
. {Pheidole cicatricosa minor
TL ca 2.3 mm, HL 0.66, HW 0.55, SL 0.69, PW 0.33; CI 87, SI 120, OI 28,  MI 36 , PI 60; head a short rectangle with the sides very weakly convex, posterior angles broad and evenly rounded, the occiput straight; with a very narrow nuchal collar; mandibles moderately long, with a mixture of minute teeth and quite coarse teeth on the masticatory margin; and two larger apical teeth; anterior margin of clypeus quite strongly convex, without a median or any other carinae; with only four forward facing, fine long hairs. Colour variable with types seemingly lighter
North Africa & Mali - cicatricosa
-- {Pheidole jordanica}
TL 3.7-4.0 mm; HL 1.70, HW 1.58, SL , PW 0.52; CI 97, SI 70, EI 22; funiculus segments 2-5 length = width; eyes twice as big as pallidula, head striated less far back so that the scape reaches beyond the striations, clypeus with a weak median that is not raised; postpetiole profile almost circular; (probably not sub-Saharan)
. jordanica
. {Pheidole jordanica minor}
TL ca 2.5 mm, HL 0.64, HW 0.52, SL 0.78, PW 0.35; CI 80, SI 141; head much paler; legs much longer and distinct groove between pro-and mesonotum (probably not from sub-Saharan)
North Africa & Sudan - jordanica
return to key THead with only shallow occipital scalloping; in profile occiput somewhat flattened

--
48 Base colour orange-brown
49

-- Base colour brownish-black
50
49 {Ph megacephala details}
TL 3.5-4.5 mm variable, HL 1.50, HW 1.50, SL 0.80, PW 0.60; CI 100, SI 54; promesonotum profile quite a high dome; propodeal spines acute and sharp but distinct; postpetiole profile with distinct angular ventral process
. megacephala
. {Pheidole megacephala minor}
TL ca 2.5 mm, HL 0.67, HW 0.58, SL 0.68, PW 0.39; CI 86, SI 120; shiny, with only sculpturation on mesonotum, propodeum and petiole, all of which are densely spiculate; red-brown, gaster darker, appendages lighter.
Pan-African tramp - megacephala

-- {Pheidole foreli major}
TL 4.5-5.1 mm, HL 1.64, HW 1.58, SL 0.83, PW 0.58; CI 96, SI 55; striations on front of head reach back to about 2/3, occiput smooth and shiny; colour piceous, appendages lighter; covered in quite abundant, long fine hairs, legs and scapes distinctly bristly
.
. {Pheidole foreli minor}
TL 2.8-3.0 mm, HL 0.75, HW 0.75, SL 0.75, PW 0.50; CI 100, SI 100; shining, no pro-mesonotal suture; mesothorax and propodeum lightly rugo-reticulate; dark brown to piceous, appendages lighter
South Africa - foreli
55 {Pheidole atrox}
TL 3.5-4.5 mm variable, HL 1.50, HW 1.50, SL 0.62, PW 0.60; CI 100, SI 41; promesonotum profile quite a high dome; propodeal spines acute and sharp but distinct; postpetiole profile with distinct angular ventral process; distinctive reticulate sculpture on the genae
. Pheidole atrox major underhead
. {Pheidole atrox minor}
TL ca 2.5 mm, HL 0.67, HW 0.58, SL 0.68, PW 0.39; CI 86, SI 120; shiny, with only sculpturation on mesonotum, propodeum and petiole, all of which are densely spiculate; red-brown, gaster darker, appendages lighter.
South Africa to South Sudan tramp - atrox

-- Pheidole scabriuscula major
Major - dense sculpturation and abundant erect hairs seems close to the minor worker below. TL ca 3.2 mm, HL 0.81, HW 0.67, SL 0.97, PW 0.42; CI 86, SI 150; PPI (postpetiole width over postpetiole length) 125
Diagnosis uncertain not scabriuscula (see above)

. Pheidole scabriuscula major underhaed
.
Pheidole scabriuscula minor
Minor - TL ca 3.2 mm, HL 0.81, HW 0.67, SL 0.97, PW 0.42; CI 86, SI 150; PPI (postpetiole width over postpetiole length) 125
Ethiopia (minor) Sudan (major) Pheidole nsp Sudan - Ethiopia

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Genus Pheidole Introduction

Contents MYRMICINAE Introduction
2007, 2008, 2009, 2010, 2011, 2013, 2014, 2016, 2017, 2018 - Brian Taylor CBiol FRSB FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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