The Ants of Egypt - Genus Pheidole Westwood - key to minor workers

Genus Pheidole Westwood (1839: 219) - key to minor workers

Pheidole main page

Key to minors - MI = mandible index, from length of masticatory margin (upper angle to base of terminal tooth) ML; MI = (ML/HW) X 100; PI = (pronotum width/head width) X 100

1	TL ca 1.7 mm; head near rectangular in full face view, with rounded posterior corners; posterior dorsum of head coarsely reticulate; postpetiole small and globular	fadli
--	TL > 2.5 mm;	2
2	Postpetiole in profile distinctly longer than high and in dorsal view distinctly longer than wide	.
.	TL ca 2.7 mm; CI 79, MI 40, SI 142, OI 30, PI 52; head in full-face view wholly oval; anterior clypeal margin with three plus pairs of long, stout, forward pointing hairs, the central pair set close together; inner margin of mandible with an evenly sized row of quite coarse teeth; lateral propodeum and petiole densely spiculate; overall colour dark yellow-brown; mandibles and appendages paler	megacephala
--	Postpetiole in profile no more than slightly longer than high and longer than wide	3
3	Postpetiole in profile somewhat flattened and slightly longer than high, in dorsal view hexagonal; petiole profile cuneiform	.
.	TL ca 2.7 mm; CI 79, MI 40, SI 142, OI 30, PI 52; funiculus segments 2-5 longer than wide; eyes near flat; head an elongated oval with a nuchal collar; anterior clypeal margin with only two pairs of long forward pointing hairs but with the central pair set at the edge of a median straight section of the margin; with a mixture of minute teeth and small teeth on the masticatory margin; and without two larger apical teeth; erect pilosity long and quite fine; shiny with very little sculpturation other than very fine longitudinal striations on the lateral head and quite coarse puncturation on the lateral mesonotum and the propodeum; overall yellow-brown with somewhat lighter appendages and pedicel	sinaitica
--	Postpetiole in profile spherical or nearly so	4
4	Petiole with a short peduncle; postpetiole with a low globular profile, from above globular and about twice as wide as the petiole	.
.	TL ca 2.7 mm; CI 79, MI 28, SI 144-151, OI 33, PI 69; funiculus segments 2-5 length = width; head near square with rounded corners and a distinct nuchal collar; eyes large and convex, clypeus weakly but distinctly carinate, with rectangular anterior margin; anterior clypeal margin with at least two pairs of long forward pointing hairs and with the central pair set at the edge of a median weakly convex section of the margin; mandibles relatively short, with a distinctive sharply curved outer margin; the teeth are coarse and relatively large; and with two small apical teeth; frontal area distinctly but shallowly impressed;very shiny with very little sculpturation other than very fine longitudinal striations on the lateral head and fine puncturation on the lateral mesonotum and the propodeum; red-brown, the Israel specimens being darker, with somewhat lighter appendages and pedicel	jordanica
--	Postpetiole seen from above wider than long	5
5	Postpetiole profile a high angular dome, from above anterior widening in a straightish line to the mid-point, posteriorly a smooth convex arc	.
.	TL ca 2.7 mm; CI 88, SI 118, OI 29, MI 40, PI 55; generally narrower and more slender than the other species, with a weakly rectangular full face appearance, without a nuchal collar; eye circular, quite large but only weakly convex; mandibles unusually large and long, with only minute teeth on the masticatory margin and without a distinct apical tooth; clypeus with the anterior margin weakly impressed but without a median or any other carinae and with only fine, not very conspicuous forward facing long hairs; frontal area distinctly and quite deeply impressed; pronotum relatively narrow, longitudinally ovoid; alitrunk profile with promesonotum shallowly convex with the pro-mesonotal suture very slightly impressed so as to interrupt the profile; the metanotal groove is distinct but shallowly impressed both dorsally and laterally; the propodeum with the dorsum convex in profile and weak lateral margination culminating in small angular prominences rather than teeth, the declivity is weakly concave; erect hairs relatively coarse; generally very shiny; fairly uniform dark chestnut brown with mandibles, legs and petiole peduncle lighter orange-red	laticeps
--	Postpetiole with low domed upper half in profile and a near flat ventral part, from above a slightly offset oval	6
6	Viewed in profile the alitrunk has a distinct transverse mesonotal welt	7
--	Viewed in profile the promesonotum is a continuous shallow curve	8
7	Post-petiole simply ovoid in dorsal view	.
.	TL ca 2.5-2.7, HW ca 0.50-0.56, HL 0.60-0.62, SL 0.62-0.67, PW 0.31. Head a somewhat elongated oval; with a narrow nuchal collar. In profile the head is ovoid, with a weakly convex underside that has a concave area towards the posterior; the dorsum is more evenly convex. Mandibles long, with a strongly curved outer margin, apically the curve intensifies; the teeth are quite small; and with two small apical teeth. Anterior margin of clypeus straight or very shallowly impressed, without a median or any other carinae; with four-six usually quite fine forward facing long hairs; clypeus weakly convex and not obviously visible from the side. Frontal carinae very short and parallel; set quite far apart, almost half the width of the head at the level of the antennal insertions. Scapes moderately long and thick, expanding distinctly in the apical third, surpassing the occiput by no more than 1/5 of their length; funiculus about 25% longer than scape; the 3-segmented club has the apical segment only about one-third longer than the pre-apical segment; the pre-apical segments are about twice as long as they are wide; the club is about the same length as the rest of the funiculus. The eye is quite small and moderately strongly convex; weakly ovoid not much longer than wide (12 facets X 10 facets); the anteriormost point is less than its own length back from the anterior point of the genae. The alitrunk profile has the promesonotum evenly convex with the pro-mesonotal suture shallowly interrupting the profile; the anterior of the mesonotum is raised into a low transverse welt; the metanotal groove is distinct but shallowly impressed both dorsally and laterally; the propodeum has the dorsum weakly convex in profile and very faint lateral margination culminating in small triangular teeth, the declivity is almost vertical. The petiole has quite a short peduncle and a low triangular profile, with the apex rounded; the postpetiole has a low globular profile and from above is near circular and about 1.5 X the width of the petiole. The gaster is narrowly ovoid viewed from above but globular in profile; it has no obvious anterior margin. The legs are relatively long with moderately swollen femora. The whole of the head, body, antennae and legs bear fine, moderately long, erect hairs; these are fairly abundant on the head, both dorsally and ventrally. The scapes and legs have short decumbent and inconspicuous hairs. Overall very shiny with very little sculpturation other than puncturation on the whole of the mesonotum and the propodeum. Also the genae have three or four curved rugae. Overall yellow-brown or red-brown, with the gaster and head often darker than the rest of the body and appendages ("teneriffana" in part)	fervens
--		.
.	TL ca 2.7, CI 80, SI 137, OI 34, MI 30-33, PI 67; head a shorter oval (Iran and Qaliobyia specimens more square); with a very narrow nuchal collar. In profile the head evenly ovoid, with the anterior margin deeply incised by the mandibular insertion. The mandibles are long, with an evenly curved outer margin; the teeth are coarse and relatively large; and with two small apical teeth. The clypeus is markedly convex, with sharply defined lateral carinae. The anterior margin of the clypeus is straight, without a median carina; the margin has four conspicuous forward facing long hairs. Frontal carinae short, but reach back to beyond the anterior of the eye; they are weakly divergent posteriorly and are set quite close together, just over one-third the width of the head at the level of the antennal insertions. The scapes are long and slender, thickening only very slightly in the apical third, surpassing the occiput by about one-quarter of their length; funiculus about 25% longer than scape; the 3-segmented club has the apical segment only about one-third longer than the pre-apical segment; the pre-apical segments are about twice as long as they are wide; the club is about the same length as the rest of the funiculus. The eye is unusually large, almost circular and strongly convex; the anteriormost point is less than its own length back from the anterior point of the genae. The alitrunk profile has the promesonotum evenly and shallowly convex with the pro-mesonotal suture quite pronounced and interrupting the profile, also being incised laterally; the anterior of the mesonotum is raised into a distinct but low transverse welt; the metanotal groove is distinct but shallowly impressed both dorsally and laterally, with cross-ribs in the lateral part; the propodeum has the dorsum very weakly convex in profile and narrow lateral margination culminating in relatively large triangular teeth, the declivity is weakly concave. The petiole has quite a short narrow peduncle and a low triangular profile, with the apex rounded; the postpetiole has a low profile globular above but near flat below; from above the postpetiole is simply ovoid and about twice as wide as the petiole. The gaster is narrowly ovoid viewed from above but globular in profile; it has no obvious anterior margin. The legs are relatively long with weakly swollen femora. The whole of the head, body, antennae and legs bear fine, long, erect hairs; these are fairly abundant on the head, both dorsally and ventrally. Short oblique erect hairs give the scapes and legs a bristly appearance. Overall very shiny with very little sculpturation other than quite coarse puncturation on the lateral mesonotum and the whole of the propodeum. The genae have sharp carinae rounding around above the eye. Overall red-brown, most with the head and gaster darker than the alitrunk, with somewhat lighter appendages and pedicel ("teneriffana" in part)	providens
.	Mesonotum not raised into a welt - pallidula-group, minors difficult to separate	.
8	Head a short rectangle with the sides very weakly convex, posterior angles broad and evenly rounded, the occiput straight;	.
.	TL ca 2.3 mm CI 87 SI 120 OI 28 MI 36 PI 60; 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;	Egypt - tristis
--	In full face view the head a somewhat elongated oval with widely rounded posterior corners; TL > 2.5 mm	9
9	Mesonotum only shallowly raised; metanotal groove narrow and marked rather than impressed; propodeal spines small	.
.	CI 83 SI 123 OI 25 MI 28 PI 65 - Croatia (Antweb); CI 87 SI 121 OI 26 MI 33 PI 63 - Egypt; head subrectangular with no more than weakly convex sides but rounded posterior angles and a slight median convexity of the occiput; without a nuchal collar; inner margin of mandible with an evenly sized row of quite small teeth; anterior margin of the clypeus is evenly but shallowly convex and is completely smooth; with a central pair of conspicuous forward facing long hairs and finer, shorter, lateral hairs The frontal carinae are very short and almost parallel; set quite close together, about one-third the width of the head at the level of the antennal insertions; frontal area distinctly delineated but not impressed at all; propodeal spines missing or highly reduced; lateral propodeum and petiole smooth and shiny; overall colour yellow-brown	pallidula
--		.
.	TL ca 2.7 mm; CI 87 SI 120 OI 28 MI 25 PI 68; head with sides strongly convex, posterior angles rounded in a near continuous curve with the convex occiput; with a very narrow nuchal collar; mandibles moderately long, with quite coarse teeth on the masticatory margin; and with two large apical teeth; anterior margin of clypeus very weakly concave medially, without a median or any other carinae; with only four conspicuous forward facing long hairs; frontal carinae short but very slightly wider apart at posterior limit; set quite far apart, about 0.4 the width of the head at the level of the antennal insertions; the frontal area (notch) is distinctly and quite deeply impressed; shiny, chestnut brown with no significantly lighter areas	arenarum
.	.	.
.	TL ca 2.8 mm; CI 87 SI 125 OI 25 MI 35 PI 52; head with sides weakly convex, posterior angles broad and evenly rounded, the anterior is only about 0.7 the width of the posterior widest point; with a very fine nuchal collar; mandibles long, with small coarse teeth on the masticatory margin; and with only small apical teeth; anterior margin of clypeus very weakly convex, without a median or any other carinae; with only four slender forward facing long hairs; lateral propodeum and petiole almost smooth and shiny; propodeal spines missing or highly reduced; overall colour yellow-brown	orientalis

href="pheidole_minor_key.htm"