The Ants of Africa

	The Ants of Africa SUBFAMILY MYRMICINAE - Genus Pheidole - separation of major workers of some African species based on photographs of the ventral head and hypostomal armature
*Genus Pheidole* Introduction**

Wilson (2003) gave drawings of the hypostomal armature of some Pheidole major workers and I have managed to take photographs for a number of the African and Middle East species. The table below shows images of the entire underside of the head, larger scale images of the armature and full face views. No scale is given but a link to the main species page is given in each case.

1	No hypostomal teeth	andrieui, kohli & rugaticeps	A
2	No or very small lateral hypostomal teeth but a well developed median tooth	mayri no image of hypostomal teeth	B
3	Single pair of hypostomal teeth set close to midline	C1: small teeth & cordiform heads - costauriensis, ingenita & rotundata also buchholzi with a longer ovoid head C2: small teeth and rectangular heads - aeberlii, bayeri, erythraea, laticeps & providens C3: large teeth & cordiform heads - albidula, concinna, melancholica & nkomoana C4: large teeth & rectangular heads - philippi & variolosa	C
4	Single pair of hypostomal teeth set more than halfway to outer edge	D1: strongly cordiform heads - impressifrons, mentita, punctulata, D2: weakly cordiform heads - abyssinica, aspera, escherichii, jordanica, megacephala, pallidula, sinaitica & squalida	D
5	Single pair of hypostomal teeth AND a strong median tooth	corticicola, decarinata & stephensi	E
6	Small pair of hypostomal teeth about one-quarter from midline and second variably sized pair at two-thirds point on recessed level	F1 clypeus with a strong median carina: caffra, senilifrons thysvillensis, speculifera & squalida F2 clypeus with a weak median carina: crinensis & nigeriensis	F
7	Small pair of hypostomal teeth about third from midline and second variably sized pair at two-thirds point on recessed level	arenarum, fervens, orientalis & cicatricosa plus, distinct from the others, occipitalis	G
8	Medium pair of hypostomal teeth about third from midline and second variably sized pair at two-thirds point on recessed level; anterior margin clearly but narrowly sclerotinised	H1: weakly cordiform heads, with long scapes - minima & pusilla H2: strongly cordiform heads - areniphila, aurivillii, katonae & tenuinodis H3: rectangular heads - sculpturata & welgelegenensis (HW > 3.0 mm, HW = HL); retronitens & schoutedeni (HW < 1.6 mm; HW < HL)	H

A	No hypostomal teeth .		.	.
.		Underside of head with faint longitudinal rugae and a strongly sclerotinised black anterior border	HW ca 1.7 mm	Sahel - rugaticeps
.		Without obvious hypostomal teeth although anterior margin seems crenulate; underside of head densely but finely rugose	HW ca 2.0 mm	Kenya & Tanzania - kohli
.		Underside of head with very faint longitudinal rugae and a weakly sclerotinised anterior border Mandibles relatively thick and strongly curved	HW ca 1.7 mm	Sahel - andrieui
B	No or very small lateral hypostomal teeth but a well developed median tooth .		.	.
.		Hypostomal teeth nil or very small but prominent black tooth as an extension of the midline; underside of head probably weakly sculptured mandibles relatively short and strongly curved	. HW ca 1.5 mm	West Africa - mayri
C	Single pair of hypostomal teeth set close to midline .		.	.
	Teeth small, head cordiform or ovoid	.	.	C1
.	Teeth small, head rectangular.		.	C2
.	Teeth large and prominent, head cordiform		.	C3
.	Teeth large and prominent, head rectangular		.	C4
.	teeth small, head cordiform or ovoid		.	.
C1		Two small black teeth set each side of the midline; anterior margin dark and with narrow but distinct sclerotinisation; underside of head smooth and shiny	HW ca 2.8 mm	West Africa - costauriensis
.		Hypostomal teeth restricted to a minute dark pair just each side of midline; underside of head with finelongitudinal rugae laterally	HW ca 1.6 mm	West Africa - ingenita
.		Underside of head with distinct sculpturation	HW ca 2.2 mm	southern & eastern Africa - rotundata
.		Hypostomal teeth restricted to a minute dark pair just each side of midline; underside of head weakly matt	HW ca 2.5 mm	West Africa - buchholzi
.	teeth small, head rectangular		.	.
C2	two minute teeth set each side of the midline; anterior margin without distinct sclerotinisation; underside of head smooth and shiny	Hypostomal teeth restricted to a very small pair just each side of midline; underside of head apparently near smooth	HW ca 1.6 mm	Horn of Africa - erythraea
.		Hypostomal teeth restricted to a very small dark pair just each side of midline; underside of head apparently with longitudinal rugae	HW ca 1.4 mm	West Africa & Congo Basin - bayeri
.		Two minute teeth set about one-third way from the midline; anterior margin with distinct narrow black sclerotinisation; underside of head shiny with curved striae	HW ca 1.3 mm	Egypt - laticeps
.		Hypostomal teeth restricted to a moderate dark pair just each side of midline; underside of head with fine longitudinal rugae curved anteriorly	HW ca 1.3 mm	Middle East & South Asia - providens
.	teeth large and prominent; head rectangular .		.	.
C3		Single pair of well developed black teeth set just each side of the midline; anterior margin sclerotinised; underside of head strongly longitudinally rugose	HW ca 2.5 mm	Gabon 143 - Gabon 143
.		Two strong black teeth set each side of the midline; underside apparently smooth	HW ca 1.1 mm	CAR DK - nsp CAR DK
.	teeth large and prominent; head cordiform .		.	.
C4		Two black teeth set each side of the midline; anterior margin with narrow sclerotinisation; underside of head very finely sculptured and dull	HW ca 1.5 mm	Cameroun & Za�re - concinna
.		Single pair of well developed dark teeth set just each side of the midline; anterior margin sclerotinised; underside of head smooth and shiny	HW ca 1.6 mm	Ivory Coast & Cameroun - melancholica
.		Teeth strong, dark brown; close to midline; underside of head smooth and shiny	HW ca 1.3 mm	Congo Basin - nkomoana
.		Two moderate sized brown teeth set each side of the midline; anterior margin without sclerotinisation; underside of head very faintly sculptured but shiny	HW ca 1.2-1.4 mm	Cameroun & Za�re - albidula
D	Single pair of hypostomal teeth set more than halfway to outer edge .		.	.
.	With strongly cordiform heads		.	D1
.	With weakly cordiform heads		.	D2
.	With strongly cordiform heads .		.	.
D1		A pair of large unicolorous teeth set about halfway from midline; underside polished but opaque	HW ca 2.7 mm	West Africa & Congo Basin - impressifrons atrocior
.		Two very large teeth over halfway across from the midline; anterior margin narrowly sclerotinised and darker than underside; underside of head smooth and shiny, with weak lateral longitudinal striations	HW ca 1.8 mm	Pan-African - impressifrons
.		Two large yellow teeth over halfway across from the midline; anterior margin without sclerotinisation; underside of head very faintly sculptured but shiny	HW ca 2.6 mm	Pan-African tramp - punctulata
.		Two moderately large teeth over halfway across from the midline; anterior margin very narrowly sclerotinised and slightly darker than underside; underside of head smooth and shiny	HW ca 1.2 mm	West African - mentita
.	With weakly cordiform heads .		.	.
D2A		Two small triangular brown teeth over halfway across from the midline; anterior margin without sclerotinisation; underside of head smooth and shiny	HW ca 1.2 mm	North Africa and western Mediterranean - pallidula
,		Single pair of large hypostomal teeth set more than halfway to outer edge; teeth only slightly darker than rest of ventral surface; underside of head weakly striate, front of head striate with long frontal carinae	HW 1.3-1.4 mm	West Africa & Congo Basin - senilifrons
.
,		Single pair of large hypostomal teeth set more than halfway to outer edge; teeth only slightly darker than rest of ventral surface; underside of head smooth and shiny	HW 1.3-1.4 mm	Egypt - sinaitica
.		Two large yellow-brown teeth over halfway across from the of the midline; anterior margin without sclerotinisation; underside of head very faintly sculptured but shiny	HW ca 1.5 mm	Pan-African tramp - megacephala
.		Two very large unicolorous teeth about halfway across from the midline; anterior margin without a distinct raised ridge; underside of head very faintly sculptured	HW ca 1.7 mm	Ethiopia - abyssinica
.		Two large yellow-brown teeth over halfway across from the midline; anterior margin with narrow sclerotinisation; underside of head very faintly sculptured but shiny	TL ca 1.2 mm	Horn of Africa - escherichii
.		Two very large light brown teeth about halfway across from the midline; anterior margin with a distinct raised ridge; underside of head smooth and shiny	HW ca 1.3 mm	Middle East, possibly Sudan - jordanica
.		Underside of head with transverse rugae	HW ca 1.5 mm	South Africa - aspera
E	Single pair of hypostomal teeth AND a strong median tooth .		.	.
.		Lateral teeth set half way between midline and sides, coarse with rounded apices; midline produced forward as a prominent dark tooth; underside of head smooth	HW ca 1.2 mm	West Africa - new species - stephensi
--		Quite strong median tooth as extension of midline; pair of slightly larger teeth set almost two-thirds across from centre; all teeth darker than underside; underside smooth and shiny	HW ca 1.1 mm	Sahel zone - decarinata
.		Lateral teeth set half way between midline and sides and quite sharp; midline produced forward as a prominent dark tooth; underside of head smooth	HW ca 1.1 mm	West Africa - corticicola
F	Small pair of hypostomal teeth about one-quarter from midline and second variably sized pair at two-thirds point on recessed level /		.	/
F1	Clypeus with strong median carina		.	.
.		Paired large hypostomal teeth about 25% away from midline, second strong pair about two-thirds of way across, set in rear layer; all teeth dark; underside of head with faint sculpturation	HW ca 1.5 mm	Southern & possibly eastern Africa - caffra
.		Paired large hypostomal teeth about 25% away from midline, second strong pair about half way across, set in rear layer; central teeth teeth orange brown; underside of head smooth	HW ca 1.4 mm	Congo - squalida
.		Paired large hypostomal teeth about 25% away from midline, second strong pair about half way across, set in rear layer; all teeth orange brown; underside of head with faint but distinctsculpturation (Congo Basin form, smaller than type)	HW ca 2.2 mm	Pan-Africa north of Angola - speculifera
.		Strong pair of dark hypostomal teeth set about one-quarter across from midline; second stronger pair set behind at about the midpoint; underside distinctly only weakly scuptured; face more elongated	HW ca 1.0 mm	West Africa - senilifrons thysvillensis
F2	Clypeus with weak median carina		.	.
.		Paired large hypostomal teeth about 25% away from midline, second strong pair about two-thirds of way across, set in rear layer; all teeth dark; underside of head with faint sculpturation	HW ca 1.0 mm	Congo Basin & West Africa - new species - crinensis
.		Aquite strong pair of hypostomal teeth set about one-quarter across from midline; second stronger pair set behind at about the midpoint; underside distinctly longitidinally rugose	HW ca 0.8 mm	West Africa - nigeriensis
G	Small pair of hypostomal teeth about third from midline and second variably sized pair at two-thirds point on recessed level .		.	.
.		Underside of head very weakly longitudinally striate	HW ca 1.5 mm	North African and pan-tropical tramp - fervens
.		Underside of head smooth, outer teeth unusually large	HW ca 1.3 mm	North Africa & Mali - cicatricosa
.		Underside of head very weakly longitudinally striate	HW ca 1.3 mm	Middle East - orientalis
.		Underside of head with weak arcuate striations, inner teeth minute, outer teeth small	HW ca 1.2 mm	North Africa & Mali - arenarum
.		Underside of head near smooth with distinct hair pits	HW ca 2.7 mm	West Africa to Gabon - neutralis
.		Underside of head near smooth with distinct hair pits	HW ca 2.7 mm	West Africa - occipitalis
H	Medium pair of hypostomal teeth about third from midline and second variably sized pair at two-thirds point on recessed level; anterior margin clearly but narrowly sclerotinised .		.	.
H1	Head weakly cordiform but with long scapes reaching posterior quarter of the head .		.	.
.		Paired large hypostomal teeth about one-thirds across from mid-line and outer pair set behind; anterior margin specially inner teeth dark; underside of head weakly striate Dark red-brown	HW ca 1.48 mm	West Africa (tramp?) - pusilla
.		Paired large hypostomal teeth about 25% away from midline, second strong pair about two-thirds of way across, set in rear layer; all teeth darker than underside but lighter than in most others; underside of head with faint sculpturation	HW ca 1.0 mm	West Africa & Congo Basin - minima
H2	Head strongly cordiform .		.	.
.		Paired large hypostomal teeth about one-thirds across from mid-line and outer smaller pair set behind; anterior margin specially inner teeth dark; underside of head striated	HW ca 1.7 mm	East Africa - areniphila
.		Paired small narrow hypostomal teeth about 25% away from midline, second strong pair about two-thirds of way across, set in rear layer; all teeth darker than underside; underside of head with faint longitudinal striation	HW ca 1.6 mm	Cameroun, Congo Basin & southern Africa - tenuinodis
.		Paired small triangular hypostomal teeth about 25% away from midline, second strong but quite short pair about two-thirds of way across, set in rear layer; all teeth darker than underside; underside of head with faint longitudinal striation	HW ca 1.5 mm	West Africa & Congo Basin - aurivillii
.		Underside of head weakly longitudinally striate	HW ca 2.8 mm	Northern East Africa - katonae
H3	Head elongated rectangular .		.	.
.		Two strong black teeth set each side of the midline; second pair set back about one third across; anterior margin dark but not distinctly sclerotinised; underside distinctly sculptured; head near square and straight sided	HW ca 3.0 mm	Eastern & Southern Africa - sculpturata
.		Paired large stout hypostomal teethset each side of midline, second strong pair about halfway across, set in rear layer; all teeth and margin near black, much darker than underside; underside of head weakly striate	HW ca 3.3 mm	West Africa & Congo Basin - welgelegenensis
.		Two strong black teeth set each side of the midline; second pair set back about halfway across; anterior margin dark and distinctly sclerotinised; underside shiny, distinctly but undefinably sculptured; head narrow and straight sided	HW 1.1-1.2 mm	Za�re & Nigeria - schoutedeni
.		Paired large stout hypostomal teethset each side of midline, second strong pair about halfway across, set in rear layer; all teeth and margin near black, much darker than underside; underside of head near smooth	HW ca 1.6 mm	West Africa & Congo Basin - retronitens