The Ants of Africa
SUBFAMILY MYRMICINAE - Genus Oligomyrmex
Key to minor workers
Contents - Myrmicinae - MYRMICINAE Introduction

Main Genus page

Key to minor or worker morph

Queen only known; subgenus Crateropsis, head with unique sculptured dorsal concavity Kenya - elmenteitae
-- subgenus Sporocleptes --
-- {Oligomyrmex villiersi antenna}TL 1.8-1.9 mm; antenna 11-segmented with a distinctive two-segmented club, the penultimate segment cup or goblet shaped; mandible with six-teeth but centre pair reduced, leaving two large apical and two large distal teeth; pronotum with rounded anterior margin; propodeum with strong superior spines, declivity with lamellate lateral margination and lower teeth Possibly a separate genus Sporocleptes Arnold
-- {Oligomyrmex politus nicotianae}(description for nicotianae) TL 1.9 mm; colour ochreous (darker in politus), gaster lighter .
. {Oligomyrmex politus} Kenya & Zimbabwe - politus
-- {Oligomyrmex villiersi}Bernard in genus Nimbamyrma; TL 1.8 mm; colour bright yellow Guinea - probable junior synonym of politus villiersi
-- {Oligomyrrnex punctatus}TL 1.0 mm; head only 1.14 times longer than wide, with markedly convex sides and long frontal carinae; propodeal teeth short but acute Kenya probable junior synonym of politus - punctatus
-- Oligomyrmex proper
--
-- Antennae 9-segmented subgenus Oligomyrmex
-- Antennae 10-segmented (note debilis 9-segmented) subgenus Aeromyrma
-- Antennae 11-segmented subgenus Aneleus
-- subgenus Oligomyrmex - antennae 9-segmented --
Major only described Uganda - convexus
Major only known Chad - diabolicus
Description inadequate; TL 0.98 mm; separation by major Nigeria - new species - boltoni
1 {Oligomyrmex angolensis minor}TL 0.8 mm; head a little longer than broad, longer than in alluaudi and less enlarged behind; the scape nearly attains the posterior fourth of the head; mandibles of four teeth; alitrunk broad in front and more marginate than in alluaudi; basal face of the propodeum clearly broader than long, with the teeth moderate, somewhat broader at the base than long; petiole a little longer than high and a little broader at the summit than in alluaudi; postpetiole rounded, narrower. Head, propodeum, and sides of the petiole matt, densely and finely reticulate-punctate, the remainder smooth and shining; colour reddish yellow Angola & Gabon - angolensis
-- TL 1.0-1.1 mm 2
2 {Oligomyrmex erythraeus}Pilosity short but copious; TL 0.9 mm; head slightly longer than wide; lateral alitrunk, head and promesonotum shiny; propodeum and pedicel densely punctate; colour yellow-brown, head more yellow .
. {Oligomyrmex erythraeus worker} Ethiopia & Gabon - erythraeus
-- Pilosity thin and sparse 3
3 Propodeum with distinct triangular teeth 4
-- Propodeum with no more than small points 5
4 {Oligomyrmex santschii worker}TL 1.1 mm; head nearly 1.2 longer than wide; mandibles 5-toothed; anterior clypeal margin produced as a sinuate lobe over base of mandibles; eyes minute; frontal lobes well developed and convex not concealing antennal insertions; propodeum with small triangular teeth; sublucid, all except pronotum and gaster with fine dense puncturation; colour yellowish-brown, antennae and legs paler CAR - donisthorpei or
Sudan - santschii
-- {Oligomyrmex frontalis}TL 1.1 mm; head less than 1.2 times longer than wide; mandibles with fine acute teeth; propodeal spines short and triangular, declivity laterally carinate; sublucid, densely punctate except on gaster, pronotum and dorsum of pedicel nodes; brownish-yellow Zare - frontalis
5 {Oligomyrmex latro}TL 1.0-1.1 mm; head one-eighth longer than wide; propodeum sub-dentate; mostly smooth, propodeum and lateral mesonotum reticulo-punctate .
. {Oligomyrmex latro} Congo & Zare - latro
-- {Oligomyrmex thoracicus}TL 1.0-1.2 mm; head 1.25 longer than wide; propodeum dorsum convex, teeth feeble; petiole short and high; shiny except for dense, coarse puncturation on propodeum; colour yellowish-brown, head and medial gaster darker (close to erythraeus) .
. {Oligomyrmex thoracicus}Non-type image Kenya & Uganda - thoracicus
-- {Oligomyrmex rhodesianus}TL 1.09, HL 0.37, HW 0.32, SL 0.23, PW 0.21; CI 88, SI 70; head sub-circular; mostly smooth and shiny; weak sculpture on propodeum
Zimbabwe - rhodesianus
return to key subgenus Aeromyrma - based on Weber (1952) - antennae 10-segmented
--
Major only known Botswana - africanus
Major only known Zare - petulcus
6 TL < 1 mm 7
-- TL > 1 mm 10
7 Antennae 10-segmented 8
-- {Oligomyrmex debilis}Antennae 9-segmented, head one-sixth longer than broad, scape attains posterior fifth of head; postpetiole 1.5 times broader than long
. {Oligomymrex debilis minor} Guinea & Gabon - debilis
8 Oligomyrmex jeanneliMandibles 4-toothed; TL 0.9 mm; scape attaining posterior third of head; head no more than lightly sculptured; postpetiole almost 2 times broader than long (major antenna is 9-segmented) Kenya - jeanneli
-- Mandibles 5-toothed 9
9 Oligomyrmex alluaudiTL 0.8-1.0 mm; head a little longer than wide; mandibles 5-toothed, eyes minute; scape slightly surpassing posterior third of head; pronotum with anterior angles rounded; propodeal spines longer than one-third their basal interval; matt with a greasy reflection, mostly reticulate-punctate; colour entirely dull yellow; antennae & legs paler Kenya - alluaudi
-- {short description of image}TL 0.8 mm; head except frons densely reticulate; propodeal declivity with a translucent lamella on each side, that dentate at both ends; postpetiole twice as broad as long; colour yellow, appendages paler Ghana - vorax
10 {Oligomyrmex arnoldiellus}Totally without eyes; TL 1.0-1.2; mandibles with 5 teeth; postpetiole 1.3 times broader than long; head smooth and shiny .
. {Oligomyrmex arnoldiellus} South Africa - arnoldiellus
-- Eyes present, even if atrophied 11
11 TL 1.1-1.2 mm 12
-- TL 1.5 mm 16
12 Propodeum without spines 13
-- {Oligomyrmex acutus}Propodeum with distinct spines, TL 1.1 mm, HL 0.42 HW 0.31; mandibles with 5 teeth; colour brown Zare - acutus
13 Head near rectangular in full face view, with straight sides 14
-- Head more ovate with convex sides 15
14 {Oligomyrmex hewitti}Mandibles 4- or 5-toothed; TL 1.1-1.3 mm; scape attaining posterior quarter of head; no propodeal lamellae; colour reddish-yellow, gaster more brown .
. {Oligomyrmex hewitti} South Africa - hewitti
-- {Oligomyrmex lucidus}Mandibles 5-toothed; TL 1.2 mm; head a little over 1.25 times longer than broad; postpetiole almost 1.5 times broader than petiole; propodeum marginate; almost unsculptured; colour yellow .
. {Oligomyrmex lucidus} Zimbabwe - lucidus
15 {Oligomyrmex incertus} .
. {Oligomyrmex incertus} Zimbabwe - incertus
-- {Oligomyrmex nanus}TL 1.2 mm; head 1.15 times longer than wide; mandibles with 4-5 teeth; propdeum more or less bordered; petiole node low and rounded; postpetiole 1.3 times broader than petiole; head with some puncturation; mesopleurae, propodeum and pedicel finely reticulo-punctate; colour dirty-yellow .
. {Oligomyrmex nanus}

Mozambique - nanus
-- {Oligomyrmex khamiensis}TL 1.1-1.2 mm; mandibles 4-toothed; propodeal dorsum flat, declivity margined with a fine lamella; head mostly shiny, propodeum faintly reticulate-punctate, rest shiny; colour pale yellowish-brown, antennae and legs ochreus Zimbabwe - khamiensis
16 {Oligomyrmex traegaordhi}TL 1.5 mm; head narrower; mandibles with 5 teeth; propodeum with very small tubercle at angle; propodeum, posterior of mesonotum and petiole node reticulate, puncturate and submatt; colour yellow with reddish tint .
. {Oligomyrmex traegaordhi} South Africa - traegaordhi
-- Oligomyrmex ugandanusTL 1.5 mm; head 1.17 times longer than broad; mandibles with 5 teeth; generally smooth and shiny but mesonotum, propodeum and petiole finely reticulate-punctate; colour dull brownish-yellow, head darker, appendages and apex of gaster paler; robust Uganda - ugandanus
return to key subgenus Aneleus - antennae 11-segmented --
17 Propodeum with junction of dorsum and declivity angular but without teeth or spines 18
-- Propodeum with distinct spines or teeth at junction of dorsum and declivity
19
18 {Oligomyrmex diabolus}TL 1.2 mm; head rectangular with straight sides; metanotal suture shallow; propodeal teeth reduced to tubercles; densely puncturate but quite shiny; yellow .
. {Oligomyrmex diabolus} Cameroun, CAR - diabolus
-- {Oligomyrrnex nsp Cameroun minor}TL 1.4 mm; head with markedly convex sides and long frontal carinae; head and alitrunk smooth and shiny
Cameroun - new species cameroun FK
19 TL < 1.2 mm 20
-- TL > 1.2 mm 21
20 {Oligomyrmex silvestrii}TL ca 1.0-1.25 mm; (note no description ever made, thus based on soldier and drawing) apparently pronotum with sharp straight anterior margin; colour testaceous red .
. {Oligomyrmex silvestrii} Ghana & Guinea - silvestrii
21 {short description of image}TL 1.8-2.0 mm; pedicel nodes especially petiole rounded in profile; head slightly longer than wide, sides convex and posterior angles sharp; mandible 5-toothed; propodeum with two small sharp spines (as in soldier); sculpturation similar to soldier but head without transverse rugae; sparse yellowish pilosity; colour testaceous red, clypeus and mandible rust brown (? Nigeria - undetermined species) Fernando Po I. & Gabon - menozzii
-- {Oligomyrmex perpusillus arnoldi}TL 1.5 mm; head elongate, sides moderately convex, occipital margin concave and sharp; pronotum with sharply defined margins; propodeum with triangular tooth on each side; petiole narrow with post-petiole barely wider; colour reddish-yellow (note arnoldi is TL 1.0-1.4 mm) .
. {Oligomyrmex perpusillus} East & South Africa - perpusillus
Contents MYRMICINAE Introduction
2007, 2008, 2010, 2011, 2013, 2015 - Brian Taylor CBiol FSB FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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