The Ants of Africa SUBFAMILY FORMICINAE - Genus Lepisiota
Contents - Formicinae - FORMICINAE Introduction

Genus Lepisiota (Mayr) (previously Acantholepis Mayr, 1861: 42)

In Tribe PLAGIOLEPIDINI.

Diagnostic Features - Antennae 11-segmented. Eyes well developed, ocelli present but may be reduced. Mandibles with the apical margin oblique and dentate, overhung by clypeus. Alitrunk constricted in the mesonotal region, the propodeum swollen and bidentate or bituberculate. Petiole a scale with the dorsal margin bispinose, bidentate or emarginate. Acidopore borne on a conical projection of the hypopygium, surrounded by a fringe of hairs.

Mayr's (1861: 42) genus description (as Acantholepis), is at . Santschi (1926a: 15) clarified and restated the definitions of the Genus and the subgenera Acantholepis and Lepisiota - these are at .

On the generic nomenclature, Bolton (1994) gave Acantholepis as reduced to the status of a homonym of Lepisiota but cited no authority and there are no modern revisions. This was used by all early authors and even as late as Belshaw & Bolton (1994b). As Hölldobler & Wilson (1990) gave the authorities as being Acantholepis Mayr 1861: 42 and Lepisiota Santschi 1926a: 15 (as a subgenus of Acantholepis), this was puzzling, but Bolton (1995) revealed the older name was applied to a fish genus from Denmark by Kroyer in 1846. Thus, Lepisiota, formerly a subgenus of Acantholepis, has to be used for the ants.

Strickland (1951a) describes them as small black ants, more likely to be found on seedling cocoa than on mature trees and essentially soil nesting. He regarded them as of little economic importance as far as cocoa was concerned.

Bernard (1952) described genus members (as Acantholepis) as more common than their relatives Plagiolepis and Anoplolepis in the Guinea, Mt. Nimba surveys; adding that the nests often are very resistant to inundation, which leads to their being abundant among the ants known from close to the River Niger (according to Monod). Under one of the species, he added that the Acantholepis are individually very variable, and refrained from describing new species as it would be better to await more examples. Bernard also referred to species in the subgenus Pseudacantholepis Santschi, being very small and poorly collected forms; and, other than A. laevis [see below as a subspecies of capensis], previously unknown from French West Africa. Bolton (1995) noting that he found no record of type species for the subgenus and (apparently) no Santschi reference, regarded the subgenus name as "unavailable".

Partial Key to species from sub-Saharan Africa

From the original descriptions, illustrations and specimens that I have drawn or illustrated, I have attempted to draw up a key to some of the species. This is not intended to be truly authorative but at least a guide to the apparent main groups. It is apparent that a modern review of the type specimens and fresh material would lead to synonymization and, especially, in the case of "capensis", separation into several more species. Having decided (2004) to expand the coverage to all species from sub-Saharan Africa, it has become clear that the dimorphism I found in the specimens still only fully identifiable as Lepisiota species T³ is not unique, or an aberrant occurrence, as Weber (1943c) described L. megacephala from a single apparent soldier. I have been unable to find any reference to dimorphism from outside Africa.

An early key which included Acantholepis species from Africa was compiled by Forel (1892a). This is at and (Indian species ) . Forel referred to capensis as having whitish erect pilosity on the body but not on the tibiae or scapes. The colour of the pilosity in the type capensis, i.e. from South Africa, however, is clearly blackish.

"L. capensis"
I have attempted to disentangle the mess with the linked Analysis.
This has led to separation of the following -
capensis (Mayr);
validiuscula (Emery);
guineensis (Mayr) new status;
issore (Weber) new status, with thoth as a variety;
laevis (Santschi) revived status, possibly separate species specularis (Santschi);
lunaris (Emery) revived status (not African);
minuta (Forel) new status;
simplex (Forel) revived status with possibly separate species simplicoides (Forel) and subopaciceps (Santschi)
acholli (Weber) may be a variety of depilis (Emery);
anceps (Forel) may be a variety of obtusa (Emery);
junodi (Forel) may be a variety of incisa (Forel).

Key to species-groups

Key to workers: (based largely on source material)

I have given scape index (SI) figures based in several instances from the original drawings - these are in brackets (SI xx), as SI seems to be one of the more useful diagnostic features.

°	Queens & males only	Somalia - somalica
°	TL 2.5 mm; petiole not described; dark castaneous brown, gaster black, antennae, tibiae & tarsi yellow-brown; close to depressa (Santschi 1914b)	Tanzania - deplanata
°	Status dubious (original source unknown)	West Africa & Congo Basin - fervida
-	Soldiers	-
0	TL 4.3 mm (assumed soldier) HL 1.54 HW 1.45; petiole with acute dorsal spines about as long as interval between their bases; bicoloured - head mahogany red, rest of body black (the colouration, propodeum with tubercles and the thin forward-angled petiolar scale suggest it is somewhat similar to the worker of L. foreli)	Sudan - megacephala
--	TL 3.2-3.6 mm; in full face view eyes distant from edges of face (for minor worker see 45)	.
.		West Africa - cacozela/species T³
-	Workers	-
1	Petiole with a pair of long, usually sharp, spines on dorsal margin	2
--	Petiole emarginate or with denticles or spines that are much shorter than the width of the petiole apex	18
2	Petiole very long, two and a half times as long as the node is high, petiole spines long, thin and straight	3
--	Petiole short, little or nor longer than node is high	5
--	Petiole much longer than height of node	--
3	TL 2.8-3.1 mm (SI 166); head and thorax ochreous, smooth and shining	Zimbabwe - arenaria
--	Head and thorax reddish-brown, dull and reticulate-punctate	4
4	TL 3.0-3.8 mm (SI 150); gaster with short, black and obtuse hairs	Zimbabwe - longinoda
--	TL 2.4 mm; erect hairs whitish clear, gaster more slender and shiny; spines on petiole even longer and narrower	Angola - angolensis
--	Petiole short	--
5	Petiole as high or higher than propodeum, with long coarse spines; TL 3.3 mm; heavily sculptured; dark red-brown almost black	Zimbabwe - rugithorax
--	Petiole clearly lower than propodeum and with narrow sharp spines	6
6	With few or no erect hairs, other than on gaster	7
--	With more than a few erect hairs	11
7	Body colour nearer black; TL 2.3 mm, head smaller and narrower, scape surpassing occiput by at least 1/3 its own length; petiole spines closer, with distance apart about the same as basal separation; head, pronotum and gaster smooth and shiny brown;	Zaïre - schoutedeni
--	Body colour predominantly brown	8
8	TL 3.0-3.2 mm (SI 136); body with head and gaster brown, thorax and appendages distinctly paler, no more than reddish brown to ochreous; scapes surpassing occiput by well over half its own length; head near circular in full face view	Zimbabwe - dendrophila
--	Body essentially unicolourous	9
9	TL 2.5 mm; (antennae missing, SI Nigeria specimens 106), head quite round; petiole in face view lyre-shaped, with tips of spines wider apart than the bases; spines long and curved backwards; head and alitrunk matt, densely and finely reticulo-punctate	.
.		West Africa & Congo Basin - ambigua
--	Petiole in face view relatively narrow, with long sharp spines	10
10	Petiole as above; scape surpassing occiput by less than 1/3 of own length	Eastern Africa - incisa
--	TL 2.7-3.0 mm; scapes long surpassing occiput by more than two-fifths of own length; differs from ambigua as pronotum more impressed dorsally, dorsum of propodeum more concave, angles with more pronounced teeth and the petiole scale (shown right) with longer spines, which are round in cross-section, thicker at the base than the apex, and distinctly curve backwards; also finer sculpturation than ambigua	Zimbabwe & South Africa - spinosior
	With abundant erect hairs	--
11	Erect hairs black; body colour variably brown to black	12
--	Erect hairs no darker than brown	13
12	Erect hairs, sparse, long black and silky, but white pubescence; TL 2.5 mm; scape surpassing occiput by about one-third its own length; body generally black, appendages brown; overall dull matt, except gaster shiny	Zaïre, Ghana & Nigeria - gerardi
--	Erect hairs long, black and abundant on head and gaster; TL 3.2 mm (SI 124); head a short oval; in full face view eyes not reaching sides of head; petiole scale distinctly triangular in profile	.
..		Zaïre & Equatorial Guinea - nigrisetosa
--	TL 3.3 mm (SI 133); head ovate, eyes large; propodeum with raised cone-shaped lateral processes; petiole with short spines each terminating in a distinct hair; head dull	.
.		Malawi & South Africa - mlanjiensis
--	Erect hairs other than black	--
13	Erect hairs short and whitish; body distinctly bicoloured, alitrunk reddish yellow, head darker, gaster black; scapes surpass occiput by less than one-third own length; propodeal spiracles at apex of short processes	Cameroun - nigriventris
--	Erect hairs long	14
14	Body black	15
--	Body brown rather than black	16
15	TL 3.0-3.4 mm; head square, sides nearly straight; scape surpassing occiput by about half its own length; propodeum with distinct teeth; petiole narrow about one and a half times as high as wide, with moderate spines; erect hairs thin, long and dark brown; scapes with basal two-thirds ochreous	Zimbabwe (?Ghana) - egregia
--	TL 2.4 mm; head ovoid (capensis shape); shorter scapes, surpassing occiput by about 1/4 of own length; body fairly stocky; propodeum with conical apices; all except metanotum and propodeum shiny; erect hairs long and whitish, no obvious pubescence; black, except apices of mandibles, most of antennae and tarsi reddish-brown to yellow	South Africa (?Cameroun) - crinita
--	TL 2.8-3.3 mm; jet black, except tibiae brown, tarsi yellowish-brown, base of scape ochreous; shiny, even propodeum which has longitudinal rugae; erect hairs abundant.	.
.		Eastern Africa & Egypt - hirsuta
--	Body no more than dark brown	--
16	Erect hairs dark; TL 2.86-3.08 mm, SI 137; colour black or dark red-brown, with yellow tarsi. Sculpturation of fine striations on the pronotum, of rugae on the mesonotum and propodeum. Erect hairs stout, dark, moderately abundant on body and head. Propodeal prominences dentate but not spinose. Petiole spines moderately developed and straight.	Nigeria - validiuscula [species T¹]
--	Erect hairs pale, yellowish	17
17	TL 2.0-2.2 mm (SI 130); erect hairs few but long, and yellow; head a distinct oval; with large eyes in full face view protruding beyond the sides; long maxillary palps; apex of petiole with moderately long posteriorly curved spines [NOTE head shape of guineensis is ovoid if viewed titled backwards, so mandibles more exposed]	.
.		Zaïre & Sudan - palpalis
--	TL 2.5-2.7 mm, SI 117; erect hairs pale, moderately long and fairly abundant; sole sculpturation long rugae on lateral mesonotum; petiole scale with distinct spines	.
.		West Africa - (species undet. 1) guineensis new status
	Petiole emarginate or with no more than short spines or denticles	--
18	TL 2.5-3.5 mm, SI 228; highly elongated with very long appendages, scapes more than twice the length of the head; black, except for brownish-yellow appendages; almost hairless	Ethiopia (Egypt & Middle East) - gracilicornis
--	Not greatly elongated	19
19	TL 3.2-3.8 mm; scapes surpass occiput by one-third its own length; black, except for brownish-yellow appendages, with a distinctive and unique metallic sheen, greenish on the head and thorax, violaceous on the gaster; pilosity of long, erect whitish hairs	Zimbabwe & Angola - submetallica
--	Otherwise coloured	20
20	Small species, TL 2.2 mm or less, with very short or no pilosity; body not entirely black or dark brown	21
--	Mostly larger species, TL > 2.2 mm; body entirely or in greater part black or dark brown	25
--	TL < 2.2 mm and with no more than very short pilosity	--
21	Whole body very smooth and shining	22
--	TL 1.6-1.9 mm; scapes just reach occiput; whole body dull; head and thorax bright red, gaster dark brown	Zimbabwe - foreli
22	Scapes just surpass occiput	23
	Scapes surpass occiput by about one third of own length	24
23	Generally unicolourous	23a
	With alitrunk, at least, distinctly lighter than head and gaster	23b
23a	TL 1.8 mm; quite dark reddish brown	Angola & Gabon - mota
--	TL 1.5 mm; scapes just surpassing occiput; jet black	South Africa - minuta
23b	TL 1.7-1.9 mm; thorax ferruginous, head and gaster dark brown (variety avunculus TL 2.3-2.5 mm)	Zimbabwe - rubrovaria
--	TL 1.7-2.0 mm; dark-reddish ochreous (deep orange-yellow), apex of gaster blackish	Zimbabwe - arnoldi
24	TL 1.7 mm; head rectangular, as wide in front as behind; scape surpasses occiput by 1/3 its own length; quite deep promesonotal suture; shiny black, basal third of scape and tarsi clear yellow, rest of appendages brown	Senegal - laevis
--	TL 2 mm; scape surpasses occiput by 1/3 its own length; altrunk convex transversely; propodeum with prominent cones; petiole fairly deeply emarginate, almost bidentate; almost no erect hairs, those seen are whitish, short and blunt; pubescence very sparse; entirely smooth & shining, except deeply striate mandibles; black	South Africa - alexis
	TL in most > 2.2 mm	--
25	Erect hairs relatively short, may be sparse	26
--	Erect hairs long and abundant	34
26	Erect hairs brown	27
--	Erect hairs whitish	30
27	Head and alitrunk shiny	28
--	Head and alitrunk matt	29
28	TL ca 2.0 mm (SI 133), shiny, appendages yellow; propodeum sculptured; petiole scale simply dentate	Southern and eastern African - capensis
--	TL 2.2-2.3 mm; head laterally and occiput convex, HW = HL; eyes slightly convex, occupying about one-third length of head and set a little forward of the mid-point of the head; scape surpassing occiput by about half its own length; petiole feebly oval, with small teeth at each side of summit; mostly subopaque with dense striations, finer on the head, gaster smooth and shiny; erect pilosity black and setiform, longer than on capensis, abundant on the gaster; pubescence sparse and pale; black but with metallic violaceous blue sheen, appendages rust, funiculi brown;	.
.		East Africa - depressa
--	TL 2.8-3.3 mm; generally stockier - scape surpasses occiput by ca 1/2 its own length; propodeal prominences more pronounced; petiole scale bidentate; longer coarser and more abundant erect pilosity; dark brown, appendages brown, scape ochreous-yellow	new status as species - Nigeria, eastern & southern Africa - validiuscula
	Head & alitrunk matt	-
29	similar to capensis but larger, TL 2.0-2.7 mm, matt with gaster shiny pubescent, gaster without erect hairs	Somalia (Arabia) - carbonaria
--	TL 1.6-2.4 mm; head longer than wide, with convex sides; matt, brown, appendages reddish, gaster metallic bronze (carbonaria relative)	Eritrea (Ethiopia) - erythraea
	Erect hairs whitish	-
30	TL 2.4 mm (SI ca 100); erect hairs very few but white and sparse pubescence; head rectangular; eyes large and in full face view unusually angled
.		Congo Basin - oculata
--	Abundant whitish pubescence; head relatively square	31
31	Petiole scale with narrow profile; erect hairs only moderately abundant	32
--	Petiole scale a quite low thick node; erect hairs quite abundant	33
32	Scape surpassing occiput by > one-third of own length, TL 2.2-2.4 mm, SI 134; erect hairs coarse and sparse	Somalia (& Egypt) - depilis
--	TL 2.3-2.5 mm (SI 103); head somewhat wider and more truncate than depilis, with scape surpassing occiput by < one-third of own length; eyes quite small	Somalia & Sudan - curta
33	With dense covering of coarse whitish hairs (dimorphic), legs long, femora with dense long pubescence; TL > 2 mm (SI 129); propodeum profile with almost flat dorsum	Eritrea (also Sinai & Arabia) - obtusa
--	TL 2.4-2.7 mm; [like simplex] propodeum simply enlarged and angular posteriorly; petiole scale feebly scalloped without teeth; [like depilis] moderately abundant yellowish-white pilosity, pubescence sparse white appressed.	Congo Basin - anceps
	Erect hairs long and abundant	--
34	Erect hairs dark brown; TL 2.4-2.8 mm?	eastern & southern Africa - simplex
--	Erect hairs no more than yellow brown	35
35	Erect hairs noticeably coloured, at least yellow brown	36
--	Erect hairs whitish or colourless	38
--	Erect hairs yellowish to brown	--
36	TL 2.7-2.9 mm (SI 124); erect hairs brown and lacking on inferior border of femur; eyes about one-third of face in size, reaching sides of face; scapes surpassing occiput by about half their own length; black, smooth and shining	.
.		Kenya & Sudan - affinis
--	Erect hairs yellow-brown,	37
37	TL 2.7 mm; head slightly longer than wide; with head in full face view eyes barely reaching the sides of the head; petiole scale with short teeth; with long pointed hairs on the inferior border of the femur; black, head and thorax strongly striated and matt	Zaïre - piliscapa
--	TL 3.4-3.8 mm, SI 136; separable by greater size and deep mesonotal and metanotal sutures, plus a peculiarly raised propodeum; petiole scale emarginate	Angola - silvicola
--	TL 3 mm; occipital margin distinctly impressed; scapes just failing to reach occiput; propodeum with obtuse teeth; petiole emarginate but without spines or even teeth; legs relatively short; erect hairs yellowish fairly oblique and with quite dense yellowish pubescence; black, appendages reddish, femora brown	Congo Basin - capitata
--	Erect hairs abundant and whitish	--
38	Head distinctly square in full face view	39
--	Head oval or nearly so	42
--	Squarish head	--
39	Head distinctly square, with barely rounded corners	40
--	Head square but with rounder corners	41
40	TL 2.3 mm (SI 93); eyes in full face view reaching edges; erect hairs long white and very abundant; smooth and shiny	Zaïre - albata
--	TL 1.8-2.2 mm (SI 100); eyes protruding from sides of head; hairs on head and thorax sparse; appearance entirely dull; due to unique very fine scabrous sculpture	Zimbabwe - quadraticeps
41	Apparently dimorphic, major TL 3.2-3.6 mm (SI 82); in full face view eyes distant from edges of face	.
.		West Africa - cacozela/species T³
--	TL 2.0 mm; eyes convex, larger than 1/3 of side of face; scapes surpassing occiput by 1/4 of own length; colour of erect hairs not given but no more than moderate in length	Eastern Africa (maybe also Guinea) - imperfecta
--	Ovoid head	--
42	Petiole with slender profile	43
--	Petiole in profile a thick scale	45
43	TL 2.2 mm; relatively large eyes; propodeum relatively short, high petiole scale; funiculus with shorter segments than canescens; little pubescence and solely long hairs	.
.	West Africa form	Angola (?Guinea) - monardi
--	Petiole lower than propodeal dorsum	44
44	TL 2.0-2.5 mm; SI 118; black and shining; petiole moderately indented; dense covering of whitish hairs a mixture of long and short hairs, femora without hairs	Sahel zone or fringes thereof - canescens
--	TL 1.8-2.0 mm; scape surpasses occiput by less than one-third its own length; erect hairs very fine, propodeum smooth; petiole scale oval from front, summit near straight	Zaïre - tenuipilis
--	TL 1.7 mm (SI 100); black and shining, head subrectangular; petiole scale at least dentate	.
.		Angola & Gabon - ngangela
--	Petiole a thick scale	--
45	Full information not available but petiole with rounded apex in profile	West Africa & Congo Basin - cacozela
.
--	TL 2.6 mm, SI 113; low petiole scale; erect hairs white and very abundant, eyes quite small	Nigeria - species T²

Subfamily Formicinae

© 2007, 2008 - Brian Taylor CBiol FIBiol FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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