The Ants of Africa
SUBFAMILY MYRMICINAE - Genus Ocymyrmex
Contents - Myrmicinae - MYRMICINAE Introduction

Genus Ocymyrmex Emery (1886: 364)

Diagnostic Features

The original genus definition, Emery (1886) - is at {original description}. Arnold (1916: 194) gave a translation, genus notes and a key (for Southern Africa), these are at {original description}. Revised by Bolton (1981b) and further by Bolton & Marsh (1989). Bolton (1981b) can be seen at can be seen at - {short description of image}. and, the full text of the latter revision can be seen at - {short description of image}.

Note 1: The genus has unusual "extremely ergatoid" queens, that differ from the workers only slightly, having thicker scapes, broader more parallel frontal lobes and usually with conspicuous transverse sculpture on the head (Bolton, 1981b: 260). See the holotype queen of Ocymyrmex nitidulus.

Note 2: Bolton & Marsh cite descriptions by "Prins & Roux (1989). Annals of the South African Museum (in press)". The full list of publications in the Annals can be seen at http://media1.mweb.co.za/iziko/education/pdfs/annals.pdf. The cited paper is not listed and, therefore, the validity of the names has to be questioned. These are cilliei, gariepensis and gordoni. Apart from characters given in the Bolton & Marsh key (1989: 1282) no descriptions exist. On the Antweb site at http://www.antweb.org//description.do?name=cilliei&genus=ocymyrmex&rank=species&project=worldants cilliei is listed as authored by Bolton & Marsh 1989 (provided by Barry Bolton, 2013); also for gariepensis at http://www.antweb.org/images.do?genus=ocymyrmex&name=gariepensis&rank=species&project=allantwebants and gordoni at http://www.antweb.org/description.do?genus=ocymyrmex&name=gordoni&rank=species&project=allantwebants

Key developed from Bolton & Marsh (1989) but without reliance on "invisible" characters, eg. palp formula and mandible teeth; distribution as per those authors.

Species-group TL mm Features .
. . Southern African Link
. . East African - Tanzania northwards - all with a low, narrow petiole node .
weitzeckeri-group
couplet 12
9.2-9.3 mm Ocymyrmex robecchiiAnterior margin of clypeus with a deep notch; dark dull red, postpetiole and gaster lighter yellowish .
. . Ocymyrmex robecchii Somalia - robecchii
. . Anterior margin of clypeus impressed to sharply notched next
weitzeckeri-group
couplet 25
7.7-8.0 mm Ocymyrmex phraxusDorsum of head densely sculptured; alitrunk dark deep red, head visibly lighter, gaster blackish-brown to black .
. . Ocymyrmex phraxus Kenya & Tanzania - phraxus
--

Dorsum of head near smooth giving a polished appearance
next
weitzeckeri-group
couplet 28
7.4-7.8 mm Ocymyrmex nitidulusPronotum profile markedly convex; shiny, glossy dull red, gaster darker blackish-brown to black
.
. . Ocymyrmex nitidulus North-east Africa - nitidulus
weitzeckeri-group
couplet 28
8.0-9.0 mm
Ocymyrmex celerPronotum profile near flat; reddish ferruginous, gaster duller .
. . Ocymyrmex celer South Sudan & Kenya - celer
. . Southern Africa - Zimbabwe southwards .
barbiger-group
couplet 20
?? Never described ?? but cf barbiger only males separable! Images of male on species page
South Africa & Namibia - cilliei
. . Anterior margin of clypeus with median semi-circular or V-shaped impression Link
. . Anterior margin of clypeus at least weakly convex without a median semi-circular or V-shaped impression (part 2) .
velox-group
couplet 5
5.8 mm Ocymyrmex turneriAlitrunk jet black and shiny; head and gaster blackish-brown; anterior margin of clypeus usually with a blunt triangular prominence
.
. , Ocymyrmex turneri Namibia (holotype, Walvis Bay) - turneri
. . Base of gaster strongly constricted to form a neck or collar Link
. . Base of gaster not strongly constricted to form a neck or collar .
velox-group
couplet 8
8.4 mm Ocymyrmex zekhemRelatively long scapes, SI 116; head very dark dull red, alitrunk glossy jet black, rest blackish-brown; basal half of gaster with numerous conspicuous hairs
.
. . Ocymyrmex zekhem Namibia (holotype only) - zekhem
--
--
Relatively short scapes, SI 105 or less
Next
velox-group
couplet 9
9.7-10.2 mm Ocymyrmex ankhuUniform rich orange brown, gaster slightly paler; basal half of gaster with no more than a few inconspicuous hairs Angola (single collection) - ankhu
velox-group
couplet 9
10.0-10.7 mm
Ocymyrmex veloxAlitrunk dull red to blackish red, both head and gaster lighter (gaster even to orange/yellow); basal half of gaster with no more than a few inconspicuous hairs .
. . Ocymyrmex velox Namibia & Angola - velox
. . Base of gaster strongly constricted to form a neck or collar .
laticeps-group
couplet 7
7.2-7.6 mm Ocymyrmex laticepsOverall red but alitrunk darker, base of gaster yellowish-orange; petiole node in profile with a short, narrowly rounded dorsum
.
. . Ocymyrmex laticeps Angola & Namibia - laticeps
laticeps-group
couplet 7
9.7 mm
Ocymyrmex cursorAlitrunk dull glossy red, head lighter with orange tint, gaster darker reddish-brown; petiole node in profile with an elongate, almost flat dorsum
.
. . Ocymyrmex cursor Angola (holotype only) - cursor
. . Anterior margin of clypeus with a median semi-circular or V-shaped impression .
. . Alitrunk profile bizarrely saddle-shaped, PF 5,3 (part 1) .
cavatodorsatus-group
couplet 3
4.5-5.0 mm
Ocymyrmex cavatodorsatusHead and appendages bright red, alitrunk and pedicel darker, gaster piceous .
. . Ocymyrmex cavatodorsatus South Africa - cavatodorsatus
cavatodorsatus-group
couplet 3
TL ?? Never fully described ??; median portion of clypeus with anterior section abruptly truncated cf cavatodorsatus but alitrunk profile not so bizarre - no images available
South Africa - gordoni
cavatodorsatus-group
couplet 1
TL ca 4.5 mm
Ocymyrmex gariepensisNever fully described ??; mandible usually (?) with only 4 teeth, rarely the third tooth with a minute denticle at its base; median portion of clypeus with anterior section abruptly truncated cf cavatodorsatus; cephalic sculpture unusual, consisting entirely of dense reticulate-punctuation South Africa - gariepensis
. . Alitrunk profile no more than shallowly concave .
. . TL < 6 mm .
kahas-group
couplet 19
5.2 mm
Entirely yellow - no images available
Namibia (single collection) - flavescens
kahas-group
couplet 19
5.8 mm
Ocymyrmex afraduHead glossy dull red, rest black with some reddish tints Namibia (single collection) - afradu
barbiger-group
couplet 21
5.8-6.0 mm
Ocymyrmex dekerusBrown, head and gaster with dull yellowish to dull orange tint, alitrunk dull reddish Namibia & South Africa - dekerus
tachys-group
part 4, couplet 15
5.4-5.5 mm
Ocymyrmex engytachysHead unicolorous dull orange-red, alitrunk red, gaster blackish (PF 2,3) Namibia (single collection) - engytachys
tachys-group
part 4, couplet 15
5.2-5.7 mm
Ocymyrmex tachysHead dark reddish-brown (mandibles and anterior lighter), alitrunk black, gaster dark brown (PF 2,3) Namibia (Skeleton Coast) - tachys
barbiger-group
couplet 21
5.5 mm
Ocymyrmex robustiorOverall shining blackish brown, gaster darker, appendages red-brown .
. . Ocymyrmex robustior Namibia - robustior
. . TL > 6 mm to 9.0 mm .
. . Alitrunk very densely hairy (part 7, couplets 31-35) .
hirsutus-group
couplet 33
6.9-7.8 mm
Ocymyrmex hirsutusUnicolorous reddish; head with distinctive transverse vermiculate rugulae behind eyes .
. . Ocymyrmex hirsutus Botswana & South Africa - hirsutus
hirsutus-group
couplet 34
7.9-8.3 mm
Ocymyrmex ignotusAll but gaster very dull red (blackish to naked eye); gaster black South Africa - ignotus
hirsutus-group
couplet 32
6.2-6.9 mm
Ocymyrmex micansOrange to orange-red, gaster lighter than alitrunk Namibia - micans
hirsutus-group
couplet 35
7.9-8.6 mm
Ocymyrmex resekhesHead & alitrunk very dull dark red, gaster orange-red to yellowish .
. . Ocymyrmex resekhes South Africa (poss Botswana, Namibia) - resekhes
hirsutus-group
couplet 35
7.1-7.4 mm
Ocymyrmex flaviventrisBright orange-yellow, gaster lighter and more yellow .
. . Ocymyrmex flaviventris Namibia, Botswana & South Africa - flaviventris
hirsutus-group
couplet 31
6.7 mm
Ocymyrmex shushanUniform bright orange .
. . Ocymyrmex shushan Namibia (holotype only) - shushan
. . Alitrunk not densely hairy (part 6, couplets 23-30) .
barbiger-group
couplet 20
6.7-7.2 mm
Ocymyrmex barbigerHead and alitrunk orange or darker brick red, gaster darker to dull brown Botswana & S. Africa - barbiger
weitzeckeri-group
couplet 25
7.3-8.0 mm
Ocymyrmex foreliUsually (in one colony only?) uniform orange-red, sometimes gaster lighter or darker Zimbabwe & South Africa - foreli
weitzeckeri-group
couplet 27
6.7-8.2 mm
Ocymyrmex fortiorHead and alitrunk unicolorous dull brick-red to lighter red, gaster blackish-brown to black .
. . Ocymyrmex fortior pan-southern Africa - fortior
kahas-group
couplet-18
6.3-7.0 mm
Ocymyrmex kahasHead dull orange-yellow, alitrunk darker reddish to reddish-brown, gaster more yellowish than head ,
. . Ocymyrmex kahas Namibia (single collection) - kahas
weitzeckeri-group
couplet 29
7.4-8.1 mm
Ocymyrmex monardiUniform dull red to reddish black; front of head with fine dense longitudinal costulae Angola & Namibia - monardi
weitzeckeri-group
couplet 30
6.3-7.3 mm
Ocymyrmex okysDull reddish but with alitrunk contrasting blackish cf monardi Namibia - okys
weitzeckeri-group
couplet 24
7.6-8.8 mm
Ocymyrmex sobekTricoloured, head dull red, alitrunk darker reddish-black, gaster dull yellowish red .
. . Ocymyrmex sobek Botswana, South Africa & Zimbabwe - sobek
weitzeckeri-group
couplet 30
6.7-7.8 mm
Ocymyrmex weitzeckeriOverall dark red to blackish red, some even darker .
. . Ocymyrmex weitzeckeriNamibia specimen South Africa & Lesotho - weitzeckeri
. . TL > 9.0 mm (part 3, couplets 11-13) .
weitzeckeri-group
couplet 11
11.6-12.6 unique mm
Ocymyrmex picardi Very dark red to black (head lightest, gaster darkest); hairs on alitrunk dark reddish-brown to black (Namibia specimens appear near black)
.
. . Ocymyrmex picardi pan-Southern Africa - picardi
. . Alitrunk densely hairy, the hairs white to silvery .
hirsutus-group
couplet 13
9.4-9.8 mm
Ocymyrmex alacer pedicelHead dull red, alitrunk darker, gaster lighter; petiole node flattened with triangular sides
.
.
. Ocymyrmex alacer pedicel Botswana & South Africa - alacer
hirsutus-group
couplet 13
9.3-10.1 mm
Ocymyrmex sphinxVery dull dark red, gaster black; petiole node from above with rounded sides
.
. . Ocymyrmex sphinx Botswana & South Africa - sphinx
Contents MYRMICINAE Introduction
2007, 2011, 2013, 2015 - Brian Taylor CBiol FSB FRES
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