SUBFAMILY MYRMICINAE - Genus Pheidole
provisional key to major workers of all African species
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The Ants of
Africa SUBFAMILY MYRMICINAE - Genus Pheidole provisional key to major workers of all African species |
| Genus Pheidole Introduction |
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In addition to the key given below, I drawn up a comparative table for the species of which I have been able to photograph the underside of the major head and, so, illustrate the arrangement of hypostomal teeth. This is at Pheidole majors hypostomal teeth. |
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Provisional key to species and separable forms
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MYRMICINAE Introduction |
© 2007, 2008, 2009, 2010 - Brian Taylor CBiol FSB
FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K. |
href="pheidole_majors_key.htm"
I
have attempted to compile a key to those species for which I have
sufficiently detailed descriptions and/or have illustrations. Two very
old keys exist - Mayer (1896) for a few species; and Arnold (1920a) for
Southern Africa. The latter provided the drawing (right) of key
anatomical features. Now the term propodeum is used rather than
epinotum; and I use the term "welt" rather than scutellum.
Postpetiole
wider than long; trapezoidal but variably dentate at widest point -
extremes shown right
Postpetiole not or hardly wider than long, only rounded or
slightly angled at sides
TL
5.3 mm; postpetiole about twice as long as wide and with a moderate,
rounded, lateral angle; head with very fine puncturation/shagreening
(much finer than rugaticeps), background of underlying
longitudinal striation which becomes oblique posterior to the eyes
angling outwards to occipital corners; erect pilosity yellowish, long
and quite abundant all over, longer and denser on the head than in rugaticeps;
colour alitrunk dark red; head, funiculus & mandible lighter;
border of mandibles, anterior of clypeus, scapes, summit of pedicel
nodes and gaster blackish; femora brown, tibiae and tarsi yellowish
brown
TL 5-6.5 mm, HW 3 mm; postpetiole scarcely wider than
long, with a moderate, rounded, lateral angle; sides of head striate to
occiput in a straight longitudinal manner; ferruginous, gaster fuscous
Head
widest at anterior margin; TL 4.0 mm; overall dark brown, appendages
lighter; erect pilosity yellowish
Alitrunk
with low or no mesonotal welt; occipital border relatively shallowly
concave; head rarely with sculpturation on occiput
Alitrunk with transverse mesonotal welt, often but not
always prominent
Petiole from above a simple elongated ellipse, with
rounded dorsal profile, postpetiole about twice as wide as long.
Frontal carinae short, with no scrobes; postpetiole about
three times as wide as long and laterally produced, dentiform or
spinose; minor with nuchal collar (?)
Postpetiole
from above smoothly ovoid; TL 3.42 mm HL 1.18 HW 1.12; appears to be
completely unique in having the frontal carinae excavated so as to
expose the base of the scape and the torus; the scape itself has a well
developed basal expansion or flange; scapes and frontal carinae
reaching three-quarter point of face; antennal scrobes while
superficial quite distinct; propodeum with sharp lateral margination
and quite deeply longitudinally concave; with large distinctive
propodeal spiracle; 
TL
7.0-8.5 mm; head with distinctive transverse striation on occiput
TL
5.0-5.6 mm; head rounded trapezoid, HL > HW, narrowed in front,
sides convex; essentially yellowish-brown
TL
5.0-6.0 mm HL 2.4 HW 2.15 mm; head rectangular sides near straight;
yellowish-red, gaster and scapes more brown
TL
4.9-5.4 mm, HL 25% > HW; head sides parallel, although slightly
convex; dark castaneous red to more brown, mandibles bright castaneous
red; 
TL
5.0-5.8 mm; head dark red to piceous, alitrunk yellowish-red, gaster
yellowish-brown; 
TL
7.0-9.0 mm, HL 2.5-2.9 = HW; head matt, with very fine reticulation;
dark red-brown, gaster darker
TL
9.5 mm HL 3.8 mm; but smaller varieties; head with puncturate
sculpturation, median occipital weakly sculptured to smooth; mesonotal
welt only moderately developed; postpetiole about three times as wide
as long; legs and antennae clothed with erect pubescence
TL
4.6-4.9 mm; propodeal spines short and triangular; colour dark
castaneous brown, posterior of head, alitrunk and petiole redder
TL
7.0 mm HL 3.02 HW 2.15 mm; alitrunk rugose, humeri with tubercules;
propodeal spines short; postpetiole laterally angular, with transverse
striations; basal segment of gaster striate-punctate; dull ferruginous
TL
6.0 mm; rust brown, gaster, scape and femora dark brown
TL
4.8 mm; propodeum with
sharper spines; vertex with finer striation
TL
5.2 mm, HL one-sixth greater than HW; alitrunk dorsum with weak
transverse striation, otherwise alitrunk and pedicel nodes densely but
superficially reticulo-punctate; erect hairs irregularly spaced on
entire body, all over long pubescence, especially abundant on gaster
and appendages; colour medium red-brown, with posterior 3/4 of head,
dorsum of alitrunk darker, anterior of head and mandibles redder.
appendages yellow-brown
TL 5.0
mm; head shape undefined; head dull, anterior striate, posterior
obliquely and finely rugose, rugosity on dorsal alitrunk tranverse;
yellowish-brown
TL 7.0 mm; head with no more than weak longitudinal
striations anteriorly, occiput with matt appearance; postpetiole near
hexagonal in dorsal view
TL 7.5 mm HL 3.0 HW 2.7; erect pilosity sparse but yellow
pubescence abundant; shiny, red-brown, antennae and legs lighter
TL
5.3; head matt with occipitum shiny, regular striation, longitudinal in
anterior two-thirds, becoming finer and converging towards occiput
where they are transverse; overall dark brown, gaster blackish
Head
completely longitudinally striate, with distinct shallow antennal
scrobes and longitudinal rugae for full length; mandibles with two
short apical teeth; antennal scapes slender, reaching to two-thirds
length of face, club relatively long and slender, segments 10-12 equal
in length to 2-9; propodeal spines at least moderate and quite sharp
Head
concave behind the eyes (i.e. with a depression in the occipital
profile)
TL
ca 3.8-4.0 mm; CI 94 SI 61 EI 19; head with longitudinal striations
reaching the occiput; these striations often strongly marked; frontal
carinae reaching the posterior quarter of the head and antennal scrobes
distinct; metanotum raised into a strong welt, metanotal groove wide;
propodeal spines robust; note the colour is quite variable
TL 4.23 mm; head striate, with occiput impressed; clypeal
margin and the mandibular apical margin are black; the antennae and
legs are light yellow; the alitrunk and pedicel slightly lighter brown
than the head; the gaster with the same colour at the base and apex,
but the second and third segment black brown
TL
ca 3.8 mm; antennal scapes almost reaching occiput with scrobes to
match; mesonotal welt distinct but not highly raised; petiole with
distinctive sloping ovoid profile; fewer but thicker erect hairs -
probably identical with pusilla
Propodeal spines no more than moderately long (ca
two-thirds of space betweeen bases), sharp and upturned
Propodeal
spines long and (mostly) relatively blunt apically 
TL 4-4.5 mm; occiput with distinct transverse rugae; with
propodeal spines no more than moderately long, triangular, sharp and
upturned; dark red-brown, gaster near black and wholly shiny 
TL
4.5-5.5 mm; occiput with reticulate sculpturation; sides of head weakly
convex in full face view; postpetiole a narrow oval in dorsal view
TL 4-4.5 mm; occiput with fine longituidinal rugae and little reticulation or transverse striation; with
propodeal spines no more than moderately long, triangular, sharp and
upturned; red-brown, gaster only slightly darker
Postpetiole
spherical and not laterally widened, in profile an obliquely angled
oval (upper posterior apex rearmost); globose; TL ca 4 mm; CI 100 SI 65
EI 18; head striated up to the occiput with scapes reaching back to the
same level; only the posterior corners of the head forwards to the
deepest outside edge of the posterior edge of the head are smooth;
clypeus with sharp median carina; funiculus segments 2-5 longer than
wide; brownish-red or more yellow
TL 4.5 mm; head barely longer than wide, median line of
head distinct but with a wide surrounding impression; sculpture of head
a fundamental reticulate puncturation with superimposed trenchant
rugae, very regular on the frons, extending with frontal carinae to
posterior quarter of the head, on the occiput the rugae are intermixed
with puncturation and large piligerous foveae; ferruginous dull, gaster
piceous and shining
TL 4.4-4.8 mm (5.76 mm Nigeria specimens); propodeum with
long thin spines; postpetiole very broad and rounded, with transparent
hind part of the lateral margin, but much wider than long and ventrally
with a small tooth; head markedly rugose all over, more reticulate on
the occiput; alitrunk dorsum transversely faintly rugose, spiculate on
lateral mesonotum, propodeum and pedicel; basal half of the first
gastral segment barely shiny, finely reticulate and spaciously
longitudinally striate; dark red-brown, gaster near black
TL up to 4.7 mm; sides
of head more convex in full face view; brownish-yellow red, legs paler.
gaster darker posteriorly
Head in
full face view with straight sides and distinctly narrower anteriorly 
Head in full face view with
arcuate sides and only slightly narrower anteriorly; 
TL
3.7-4.2 mm; overall rust-red; gaster yellower, more brown in posterior
half; mandibles and scapes brown rust; lower legs and funiculi
yellowish.
TL 5.0-5.5 mm; propodeal spines long and distinctly down
curved in profile; overall rich ferruginous red; clypeus and borders of
mandibles black; legs and antennae paler and more yellowish red
TL 4.0-4.5 mm; deep piceous,
almost black; propodeal spines long and slightly downcurved
TL 4.25-4.7 mm; very deep red-brown; antennae very small
with even shorter scapes. 
Head
with sides mildly convex in full face view; mandibles very stout with
dentate border and distinct apical teeth; clypeus with at least a
shallow central notch and lateral carinae extending forward; with
relatively swollen three-segmented club; postpetiole hexagonal, with
distinct lateral prominences; 
Head
straight sided in full face view; mandibles very stout edentate border
and without apical teeth; clypeus with median carina but anterior
margin no more than medially concave; with relatively slender
three-segmented club; postpetiole with distinct lateral prominences
produced as broad to acute spines
Black; head with strange lateral profile; TL 3.6-3.8 mm;
probable synonymy
Small
species (among the smallest of the genus), TL < 3.0 mm; colour of
head and alitrunk dark yellow, rest paler
TL
3.4-3.5 mm; generally pale yellow-brown
TL
3.8-4.0 mm HL 1.5 times HW; vertex only longitudinally striate; head
reddish-brown, alitrunk and gaster very dark-brown ((ssp fugax,
type lighter?)
TL
ca 8 mm; propodeal spines of major relatively long, stout and upturned;
petiole with a markedly emarginate narrow dorsal face; postpetiole
strongly produced laterally to form a blunt triangular process. Colour
red-brown, dull due to dense puncturation and abundant covering of
moderately long, semi-prone, fine hairs. 
TL
6.2 mm; head relatively shiny especially on occiput; with sparse
whitish fine erect hairs; postpetiole broader than long, its sides
produced as short, acute, backwardly directed spines, the distance
between the tips of which is about three times the width of the petiole
TL 4.5
mm; quite distinctive, especially the elongated head with a bulging
occiput when viewed in profile; head brown, body darker posteriorly to
a near black gaster, tarsi yellow; erect hairs long, fine and abundant.
TL
5.5-6.0 mm; dark ferruginous red, extremities darker brown to blackish
TL
3.5-3.8 mm HL 1.2 HW 1.0; clypeus witout a distinct median carina, all
striations on front of head straight; mahogany red, extremities more
brown
Head
cordiform (heart-shaped); propodeal spines upturned, stout and blunt;
postpetiole profile globular, in dorsal view wider than long, hexagonal
with rounded lateral prominences
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
TL
ca 3.5 mm; head shape distinct - West African & Congo Basin records
dubious
TL 4.3 mm; posterior of head striate and matt, except for
shiny areas on vertex; black or very dark brown with anterior of head
and sides of mesonotum red-brown
TL
ca 7.0 mm; petiole profile narrow & squamous, postpetiole from
above with arcuate anterior margin and obtuse lateral angles; sparse
pilosity; piceous (pitch black) with anterior of head and coxae dull
ferruginous, apparently variable to dark mahagony 
TL 4.2-4.5 mm; 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;
TL 4.6-5.0 mm; occipitum matt with rugulo-reticulation;
dorsum of propodeum a third longer than wide; major and minor brown
with reddish appendages (originally mistaken for punctulata by
Mayr).
TL
> 5.3 mm - 8.0 mm; head mostly smooth, dorsum shiny; dark red-brown,
gaster and anterior of head with mandibles darker
TL
5.8-6.2 mm HL 2.3 HW 2.0; head widest in posterior fourth; 
TL
< 5.0 mm; colour brown to testaceous, appendages not significantly
different
TL < 3.4 mm; alitrunk profile smoothly domed, as is
propodeal profile, propodeal spines reduced to sharp denticles
TL 2.89 mm; scape length only
0.4 of HL; dorsum of head and entire alitrunk densely spiculate in the
minor, but head only faintly spiculate in the major; propodeal spines
of major short and acute; erect hairs moderately abundant; orange,
gaster very dark brown
TL 2.0-2.2-2.4 mm; HL greater than minima; frontal
carinae and scape reaching the posterior third of face and carinae
delimiting shallow scrobes; smooth and shiny, head except vertex and
sides of alitrunk matt, finely granulo-punctate with longitudinal
striations of lateral alitrunk (as minima); erect pilosity
quite long and quite abundant; yellow with brownish tinge 
TL 3.2-3.4 mm HL 12-20% greater than HW; 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
Antennal
scapes almost reaching occipital border; TL 2.1 mm (ssp faurei
TL 2.5-2.7 mm); HL > HW; red-yellow or brown-yellow
TL
2.6-3.1 mm; frontal carinae reaching posterior quarter of head; eyes
more obviously convex; pronotum with more pronounced lateral tubercles;
propodeum with sharp lateral margination; abundant long fine pilosity;
colour a little darker than megacephala
Frontal
carinae quite short
With
relatively long narrow propodeal spines; TL 4.0-4.3 mm; 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
Uniquely with posterior border of basal two segments of
gaster having a row of triangular depressed tubercles, each giving rise
to a long hair; TL 4.0 mm; HL = HW, sides 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
Head
with deep occipital scalloping; in profile occiput smoothly convex
TL
3.5-4.5 mm variable; promesonotum profile quite a high dome; propodeal
spines acute and sharp but distinct; postpetiole profile with distinct
angular ventral process
TL 3.7-4.0 mm; CI 95 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)
TL 4.0-4.5 mm; HL 1/5 > HW; 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
TL 3.5 mm; 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
TL
4.0-4.5 mm; CI 100 SI 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
TL
4.5-5.1 mm; colour piceous, appendages lighter; ID questionable