The Ants of Africa
SUBFAMILY AENICTINAE - Genus Aenictus Shuckard

Bolton (1990b, 1994) raised this as a new monogeneric subfamily, within the doryline section.


Genus Aenictus Shuckard (1840b: 266).

Diagnostic Features - Antenna 10-segmented; eyes absent; clypeus reduced bringing antennal sockets very close to anterior margin of head; pedicel of two segments; pygidium not impressed nor armed with spines or teeth. Posterior margin of clypeus and lobes of frontal carinae raised to form a ridge around the antennal insertions. Genae lateral of each antennal insertion with a carina of variable length. Dorsum of alitrunk without sutures, metanotal groove usually impressed. Monomorphic.

Shuckard's (1840b) genus description is on {original description}

The names given below are those listed by Bolton (1995). This presents something of a conundrum, as there is no published revision of the Afrotropical members of the genus and, like Dorylus many "species" are known from males only or workers only, suggesting some duplication of species. Whilst five species are known from workers and associated queens, there are no associated males and workers.
Gotwald & Barr (1987) made quantitative studies on many members of the whole genus, which is solely found in the Old World. They described how ten African species appeared to fall into a distinct group, within the subgenus Aenictus. Interestingly, although they would appear to have recognised that there might be three valid subgenera, Bolton (1995) denoted the subgenera as all synonymous under Aenictus. Moreover Gotwald & Barr (1987) named only one of the ten African species which they listed, Aenictus asantei, and noted that Gotwald was "currently revising" the African species. To date, however, it seems that this has not been published.

Bernard (1952) wrote how these eyeless, subterranean ants are numerous in Africa, with 37 species, with new forms being continually detected. He thought that it was the sole ant genus which does not reach its maximum diversity in "Congo-Rhodesia", but far from there in the north and east, from Senegal across to Sudan and Somalia; that region having some 19 species (Congo 13 and southern Africa 7); two other forms were Saharan. Relatively few forms appeared to be other than from lowland areas.

Often display 'army ant' habits, with narrow marching columns in leaf litter (Gotwald & Barr, 1987). Described as feeding primarily on other ants by H÷lldobler & Wilson (1990, pages 560, 581 and 595).

Radoszkowsky (1881) listed Aenictus unicolor F Smith, from Angola, collected by Welwitsch. Bolton (1995: 61) has this as a nomen nudum.

See below for information on Queens and Males.


Key to workers known from Africa

0 {Aenictus maroccanus}TL 2.5 mm; mandible triangular with internal angle rounded; eyeless; scape slightly passes midpoint of head; propodeal separated from dorsum by a weak crest; sub-petiole process with a strong tooth angled forward; whole body reddish-brown, gaster lighter, head darker
Separable from the worker of A. vaucheri, also from Morocco, see bottom of this page, by being much smaller.
Note from Aktaš et al. (2004)
Morocco - maroccanus
1 {Aenictus weissi}Large, TL > 4.5 mm, stocky, heavily sculptured; head longer than wide, widest at anterior margin; propodeum with distinct teeth; abundant long pilosity, dark brown except gaster which is golden yellow.

.
. {Aenictus weissi} West Africa & Congo Basin - weissi
-- Smaller 2
2 {Aenictus villiersi}TL 3.0-3.2 mm; petiole with no more than a convex ventral profile, no distinct process; postpetiole with a low profile; head & alitrunk red; rest yellow .
. {Aenictus villiersi}TL from Antweb scales, ca 3.8 mm Guinea - villiersi
-- {Aenictus eugenii pedicel}Petiole with a distinct ventral process 3
3 Head more or less rectangular, longer than wide 4
-- Head near circular in full-face view other than less curved posterior border; petiole with smaller triangular, rearward or downward directed ventral process 9
4 Aenictus rixatorVery small, TL < 2 mm; head rectangular; mandibles narrow with 3 teeth; propodeum dorsum convex, declivity triangular, margined by a distinct ridge; pedicel nodes longer than wide; petiole with very short anterior ventral tooth; dirty yellow with brownish tinge, head and alitrunk rust-yellow South Africa - rixator

Larger, TL > 2.0 mm; petiole with large anterior directed ventral process 5
5 Petiole with triangular antero-ventral process 6

Petiole with blunt, rounded to square antero-ventral process 8
6 {Aenictus mariae}TL 2-3 mm; scape not reaching beyond mid-point of head; mandible with acute apical tooth and 4 small teeth on inner margin; alitrunk relatively short and broad; major reddish-ochre .
. {Aenictus mariae} South Africa - mariae
-- With propodeum about 1.5 X as long as wide 7
7 {Aenictus mentu}TL 1.7-2.5 mm; mandibles short, stout, with acute apical tooth and three denticles; propodeum rounded in profile; from above petiole 1.6 X broader than long and rectangular; pale ferruginous South Sudan - mentu
-- {Aenictus rotundatus pedicel}TL 2.3-3.8 mm; mandible with large apical tooth and 8-9 small teeth; scape reaching posterior four-fifths of head; anterior clypeal margin with denticles; propodeal declivity margined but only slightly concave; sub-petiole process triangular; whole body red ochre .
. {Aenictus rotundatus pedicel} South Africa - rotundatus
8 {Aenictus congolensis}TL 2.4-3.4 mm; scape reaching posterior sixth of head; propodeum with small but distinct denticles; dark red-brown, gaster browner .
. {Aenictus congolensis} Congo Basin - congolensis
-- {Aenictus guineensis}TL 2.6 mm; scape reaching just past mid-point of head; propodeum with smoothly rounded profile; orange yellow; only sculpturation is faint spiculation on posterior alitrunk .
. {Aenictus guineensis} West Africa - guineensis
9 Mandible without a large basal tooth, relatively narrow 10
-- {Aenictus decolor}Mandibles thick, with large basal tooth; TL ca 3.3 mm; head more elongate, though still convex; mandibles thick, with large basal tooth; anterior border of clypeus with median process; petiole with no more than a low ventral process; rusty-red; sides of alitrunk longitudinally rugose .
.- {Aenictus decolor} West Africa (? East Africa) - decolor
10 Mandibles narrow; with sharp apical tooth but others reduced to denticles 11
-- {Aenictus asantei}TL 2.5-3.9 mm; mandibles thick but with pronounced longer apical tooth; anterior border of clypeus with denticles; shiny, polished appearance, except for posterior alitrunk, finely reticulopunctate West Africa - asantei
11 {Aenictus eugenii}TL 3.7-4.0 mm; head widest at anterior; scape long reaching posterior border of head; anterior clypeal margin with a pair of small denticles; propodeal declivity markedly concave; head & alitrunk bright castaneous red, gaster lighter .
. {Aenictus eugenii} East & South Africa - eugenii
-- {Aenictus brazzai}TL 2.8-3.2 mm; apparently very similar to eugenii but smaller and lacking teeth on the clypeus (according to Santschi but seemingly suhc teeth are present) Congo - brazzai
-- Head widest in the middle 12
12 {Aenictus furibundus}TL 2.4-3.7 mm; head widest medianly; mandibles with large apical tooth and 6-7 small teeth; clypeus very short apical margin with numerous small teeth; reddish-ochreous, gaster lighter .
. {Aenictus furibundus} Zimbabwe & South Africa - furibundus
-- Aenictus steindachneriSides of propodeum and metasternum with plentiful backwardly direct pubescence (rotundatum with little or no pubescence); propodeum like rotundatum but declivity deeper and margined only laterally South Africa - steindachneri

Queens

An illustration of the queen of Aenictus asantei was given by Campione, Novak & Gotwald (1983). Otherwise queens are known only for Aenictus congolensis, Aenictus decolor, Aenictus eugenii, and Aenictus weissi (without description).

{Aenictus asantei queen}

{Aenictus congolensis}The photomontage of the A. congolensis type queen is collated from http://www.antweb.org/specimen.do?name=casent0911419


Many species are known only from from males - link to a provisional key.

* Santschi (1920d) gave illustrated descriptions of several of these male-only species; this is at {original description}.


Aenictus species (indet.) (1)

In Ghana, a single specimen was found by Belshaw & Bolton (1994b) in a leaf litter sample from secondary forest at CRIG.


Aenictus species (indet.) (2)

A single specimen was collected from secondary forest leaf litter at Atewa Forest Reserve in Ghana, by Belshaw & Bolton (1994b).


{link to the Hymenoptera Name Server} Extra-limital but possible is Aenictus vaucheri Emery (1915a), type location Morocco, worker described by Santschi (1936c) - see the queen at http://www.antweb.org/specimenImages.do?code=casent0903754

Emery's (1915a) description is at {original description}. Santschi's (1936c) description of the worker is at {original description}. No images of workers on Antweb (September, 2014)

Emery, C. 1915. Contributo alla conoscenza delle formiche delle isole italiani. Descrizioni di forme mediterranee nuove o critiche. Ann. Mus. Civ. Stor. Nat. Genova, (3)6(46),: 244-270. [HNS 11725]

ę 2007, 2008, 2009, 2010, 2011, 2013, 2014, 2016 - Brian Taylor CBiol FRSB FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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