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The Ants of
Africa SUBFAMILY FORMICINAE - Genus Plagiolepis |
Contents - Formicinae - FORMICINAE Introduction |
Diagnostic Features - Antennae 11-segmented. Eyes well developed and situated in the middle of the sides of the head. Ocelli usually absent. Mandibles with five teeth, clypeus large and projecting over the basal borders of mandibles. Alitrunk short, weakly constricted between pronotum and propodeum. Propodeum unarmed. Petiole a reduced scale, inclined forwards and may be overhung by the first gastral segment, never armed or emarginate. Acidopore borne on a conical projection, surrounded by a fringe of hairs. Monomorphic or polymorphic.
Mayr's (1861) genus description is at .
The Genus has over 50 recognised members throughout the Old World tropics and subtropics, plus the Mediterranean area and Australasia. Southern and Eastern Africa have around fifteen species and, so, it is perhaps surprising that West Africa and the Congo Basin have only two recognised species, plus a few so far undefined forms. It may well be the case, however, that the Genus members are primarily associated with arid or semi-arid climates.
Santschi (1914e: 36) erected the subgenus Anacantholepis for Plagiolepis in which the metanotum is very raised and distinctly separated from a short convex propodeum (he regarded it as an intermediate transition to the genus Lepisiota (as Acantholepis).
Thus, Arnold (1922) used -
Anacantholepis Santschi - metanotum very prominent, separated
from the short and convex propodeum by a deep suture (metanotal
groove); propodeum higher than the metanotum; rarely polymorphic.
Plagiolepis Mayr - metanotum not prominent; metanotal-propodeal
suture (metanotal groove) usually feeble; propodeum oblique, not higher
or not much higher than the metanotum; small species, not polymorphic.
He also provided a (rather confusing) key, including the now separate
genus Anoplolepis: the part covering Plagiolepis is at .
Santschi (1926a) clarified and restated his definitions of the Genus
and the subgenera Plagiolepis and Anacantholepis. These
are at .
Bolton (1995) had "Anacantholepis provisional junior synonym of Plagiolepis; Brown, 1973b: 178 (unconfirmed)". This was asserted again by Bolton (2003: 268), with the added remark that he found it impossible to resolve whether Plagiolepis and Lepisiota - "represent a single genus" or "the mass can be resolved into more than (that sic) two genera".
Bolton (2003), however, referred to Santschi's (1914c) definiton of Anacantholepis as "those species in which the metanotum, when viewed in profile, was more prominent dorsally, and the propodeum more strongly convex than was 'normal' in the genus". Bolton continued - "Both these features are marked only in the South African type species, P. (A.) decora, being less well developed elsewhere and intermediate".
Simple examination of the descriptions and illustrations (see the key below) reveals that the Santschi separation is very clear for several species and the subgenus appears to fully merit its status. Accordingly, I have returned to the situation prior to statements of Brown and Bolton, neither of whom appear to have given any supporting evidence or to have undertaken a review of the described species.
The Mediterranean/North African species Plagiolepis (P.) pallescens, Plagiolepis (P.) maura and Plagiolepis (P.) schmitzii can be seen on the links.
Provisional key to workers of sub-Saharan members the Genus Plagiolepis (based primarily on historic descriptions)
¤ | Queen only - photographs on species page - genus status uncertain |
South Africa - capensis |
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subgenus Plagiolepis - 9 |
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subgenus Anacantholepis - 2 |
- | Subgenus Anacantholepis | - |
2 | ![]() |
South Africa - deweti |
-- | Scapes surpassing occiput by no more than one-quarter of own length | 3 |
3 | Scapes surpassing occiput by about one-quarter of own length | 4 |
-- | Scapes surpassing occiput but by less than one-quarter of own length | 6 |
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South Africa - jouberti |
-- | Monomorphic and not wholly black | 5 |
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South Africa - polita |
-- | ![]() |
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Zimbabwe & Tanzania - chirendensis |
6 | Scapes distinctly surpassing occiput | 7 |
-- | Scapes scarcely surpassing occiput | 8 |
7 | ![]() |
. |
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Lesotho - simoni |
-- | ![]() |
South Africa - fuscula |
-- | ![]() |
. |
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Kenya & Tanzania - pictipes |
-- | ![]() |
. |
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Sudan & Cameroun (Congo Basin) - sudanica |
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Southern Africa - vanderkelleni |
-- | ![]() |
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South Africa - decora |
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subgenus Plagiolepis | - |
9 | ![]() |
10 |
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11 |
10 | ![]() |
. |
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Pan-African - brunni |
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Pan-African & tramp - alluaudi |
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Ethiopia - abyssinica |
. | Alitrunk with distinct pro-mesonotal suture; head usually with concave occipital margin | - |
11 | ![]() |
Zambia - livingstonei |
-- | Scapes attaining but hardly surpassing occiput if at all | 12 |
12 | TL at least 1.9 mm; scape clearly attaining or slightly surpassing occiput | 13 |
-- | TL < 1.5 mm | 15 |
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. |
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South Africa - intermedia |
-- | TL no more than 2.0 mm | 14 |
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Lesotho - montivaga |
-- | ![]() |
South Africa - funicularis |
15 | Occiput medially impressed | 16 |
-- | Occiput convex not medially impressed | 17 |
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South Africa & Mediterranean - pygmaea |
-- | ![]() |
South Africa - puncta |
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Zaïre - mediorufa |
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Sudan and tramp - Plagiolepis exigua |
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Subfamily Formicinae |
© 2007, 2010, 2011, 2013, 2014 - Brian Taylor CBiol
FSB FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K. |
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