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The Ants of
Africa SUBFAMILY MYRMICINAE - Genus Strumigenys |
Contents - Myrmicinae - MYRMICINAE Introduction |
Revised by Brown (1954), Bolton (1983) and Bolton (2000).
Diagnostic Features - Antennae 6-segmented, with the second and third funicular segments reduced. Antennal scrobes present. Often the ventrolateral margin of the head is excised in front of the eye to form a preocular notch. Mandibles elongate, linear, with the preapical armament usually of two teeth on the distal portion of the blade, occasionally one of these teeth is missing. Apical armament of the mandible is a fork of two spiniform teeth, with or without intercalary denticles. All orange-brown, some darker.
F Smith's (1860c) genus definition is at , see also S. mandibularis. An early key to African and Madagascar
dacetines is that of Santschi (1913b); that, with modern annotation, is
.
Rigato (2006) added two new species - S. alessandrae and S. bartolozzii.
Key to workers of African species (adapted and updated from Bolton, 1983; also plus Bolton, 2000): in addition to the usual measurements, Bolton used ML = straight line length of mandible from anterior clypeal margin to the apex of the mandible, from which he used MI = ML/HL X 100.
1 | Preocular notch present; ventrolateral margin of head impressed, notched or indented immediately forward of the eye (may be reduced in adrasora and rukha) | 2 |
-- | Preocular notch absent; no impression of ventrolateral margin of head forward of the eye | 23 |
- | Preocular notch present | - |
2 | Blade of left mandible with 1 preapical tooth (occasionally with a very small vestige of a second tooth); reticulate-punctate propodeal dorsum | 3 |
-- | Blade of left mandible with 2 preapical teeth | 7 |
-- | ![]() |
Ethiopia - alessandrae |
- | Blade of left mandible with 1 preapical tooth (occasionally with a very small vestige of a second tooth); reticulate-punctate propodeal dorsum | - |
3 | Small TL no more than 2.5 mm | 4 |
-- | TL at least 2.9 mm | 5 |
4 | ![]() |
Cameroun south to Angola - bernardi (part) |
-- | ![]() |
Tanzania - new species - ulugurensis |
4 | ![]() (no Antweb images) |
Ethiopia - bartolozzii |
- | TL at least 2.9 mm |
- |
5 | ![]() |
. |
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Ethiopia, Kenya & Tanzania - londianensis |
-- | Pronotal humeri with fine flagellate hairs; mandibles with hairs on inner margins; scapes with rearward directed but relatively short spatulate hairs; propodeum with sharp teeth | . |
6 | ![]() |
Burundi - transenna |
-- | ![]() |
. |
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Eastern Congo basin & Ethiopia - sarissa |
Blade of left mandible with 2 preapical teeth | - | |
7 | Mandibles straight | 8 |
-- | Mandibles distinctly bowed | 9 |
8 | ![]() |
. |
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West Africa - cacaoensis |
-- | ![]() |
. |
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Pan-African tropics & tramp - rogeri |
9 | ![]() |
10 |
-- | ![]() |
17 |
10 | Antennal scapes relatively long (SI 79-92) | 11 |
-- | Antennal scapes relatively short (SI 64-74) | 12 |
11 | ![]() |
. |
. | ![]() |
West Africa - vazerka |
-- | ![]() |
Cameroun south to Angola - bernardi (part) |
Antennal scapes relatively short (SI 64-74) | - | |
12 | ![]() |
. |
. | ![]() |
Southern Africa - pretoriae |
-- | Eyes smaller no more than 0.20 X HW | 13 |
13 | ![]() |
. |
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West Africa & Congo Basin into S Sudan - petiolata |
-- | Pronotal humeri with flagellate hairs | 14 |
14 | ![]() |
. |
. | ![]() |
South Africa - faurei |
-- | Postpetiole dorsum no more than weakly sculptured (may be concealed by a waxy bloom) | 15 |
15 | ![]() |
. |
. | ![]() |
West Africa - rufobrunea |
-- | Distal preapical tooth of left mandible short and separated from the proximal tooth by a distance much less than the length of the distal tooth | 16 |
16 | ![]() |
Zimbabwe - shaula |
-- | ![]() |
Burundi - dromoshaula |
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Preocular notch not continued on to the ventral surface of the head; ventral surface convex and without impressions behind the post-buccal groove or impression | - |
17 | ![]() |
Angola - helytruga |
-- | Eyes with more than 8 ommatidia; mandibles with outer edge convex; SI 65-77 | 18 |
18 | ![]() |
. |
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Cameroun & Gabon - totyla |
-- | Pronotal humeri with flagellate hairs | 19 |
19 | ![]() |
. |
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Congo Basin - xenohyla |
-- | ![]() |
19A |
19A | ![]() |
Tanzania - percrypta |
-- | In profile ventral spongiform lobe on postpetiole at least equalling the visible area of postpetiole dorsum; lamella on propodeal declivity broad and involving the teeth | 20 |
20 | ![]() |
. |
. | ![]() |
Rwanda & Burundi - adrasora (part) |
-- | In profile ventral spongiform lobe on postpetiole at least equalling the visible area of postpetiole dorsum; lamella on propodeal declivity broad and involving the teeth | 21 |
21 | ![]() |
East Africa - rukha (part) |
-- | In dorsal view postpetiole with spongiform material restricted to apices of posterior transverse strip and not projecting in front of the dorsum | 22 |
22 | ![]() |
. |
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Congo Basin - relahyla |
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Zimbabwe - dyshaula |
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Preocular notch absent | - |
23 | Blade of left mandible with 1 preapical tooth | 24 |
-- | Blade of left mandible with 2 preapical teeth | 27 |
24 | ![]() |
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Southern Africa - irrorata |
-- | Brownish-yellow or yellow | 25 |
25 | ![]() |
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East Africa - katapelta |
-- | TL no more than 1.8 mm; apical fork of left mandible without an intercalary denticle between the spiniform teeth; dorsum of head with a row of 4 erect hairs close to the occiput and an anterior pair; head narrower CI < 80 | 26 |
26 | ![]() |
Cameroun & Gabon - paranax |
-- | Pronotal humeri each with a long fine flagellate projecting hair | 26A |
26A | With head in full-face view
mandible increases in width from apex to base; upper scrobe margins
strongly convex; cephalic ground-pilosity spoon shaped; TL 1.8 mm HL
0.45 HW 0.38 SL 0.26 (no images, colour like others assumed) |
South Africa - rakkota |
-- | ![]() |
Congo Basin into Uganda - dextra |
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Blade of left mandible with 2 preapical teeth | - |
27 | Species with short compact mandibles and short variously broadened scapes | 28 |
-- | Species with long mandibles and slender scapes | 32 |
28 | Head in full face view with post-ocular area essentially heart-shaped; arboreal | 29 |
-- | Head in full-face view with post-ocular area with straight or near straight sides | 30 |
29 | Dorsum of postpetiole finely reticulate-punctate, SI 79; no illustrations | Tanzania - didyma |
-- | Dorsum of postpetiole smooth, SI 57-63 |
29A |
29A | ![]() |
. |
. | ![]() |
West Africa - pallestes |
-- | Pronotal humeri with projecting hairs; petiole
dorsum punctate; TL 2.4-2.5 mm, HL 0.62-0.66, HW 0.48-0.50, CI 75-77,
MI 35-37, SL 0.30-0.32, SI 60-63; yellowish brown (no available
illustrations) |
South Africa - marleyi |
30 | ![]() |
. |
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Congo Basin into Uganda - tetraphanes |
-- | Leading edge of antennal scape expanded but less dramatically | 31 |
31 | ![]() |
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West Africa - spathoda |
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Cameroun, Angola and east into Kenya & Zimbabwe - stygia |
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Species with long mandibles and slender scapes | - |
32 | Pronotal humeri without flagellate hairs | 33 |
-- | ![]() |
36 |
33 | ![]() |
. |
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Cameroun & Ghana - korahyla |
-- | Antennal scape broadest about the midlength and narrowing both ways; mandibles and scapes shorter, head broader, MI 35-41, SI 65-75, CI 74-84 | 34 |
34 | ![]() |
Gabon - ultromalyx |
-- | Postpetiole weakly sculptured and dull | 34A |
34A | ![]() |
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eastern Africa - arnoldi |
-- | Postpetiole weakly sculptured and dull | 35 |
35 | ![]() |
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Kenya - omalyx |
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Pronotal humeri with flagellate hairs | - |
36 | ![]() |
37 |
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38 |
37 | ![]() |
Cameroun - bitheria |
-- | ![]() |
Ivory Coast & Ghana - nimbrata |
Funicular segments 2 and 3 small but clearly visible | - | |
38 | Postpetiole
node sculptured |
38A |
-- | Postpetiole node smooth and shining | 39 |
Postpetiole node sculptured | - | |
38A | ![]() |
Sao Tome & Principe - cenagra |
-- | ![]() |
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Rwanda - murshila |
Postpetiole node smooth and shining | - | |
39 | ![]() |
40 |
-- | ![]() |
43 |
40 | Mandibles and scapes longer,
MI 42-50 SI 80-90; left mandible with distal preapical tooth at least
half length of proximal tooth |
41 |
-- | Mandibles and scapes shorter, MI 42-50 SI 70-77; left mandible with distal preapical tooth distinctly less than half length of proximal tooth | 42 |
41 | ![]() |
. |
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South Africa - havilandi |
-- | ![]() |
Uganda - semicrypta |
42 | ![]() |
. |
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Zimbabwe - mesahyla |
-- | Dorsum of head with 6 erect hairs; ground pilosity broadly spatulate everywhere; in profile postpetiole with ventral spongiform lobe much larger than equal to the exposed area; L 2.0-2.1 mm, HL 0.52, HW 0.41, CI 75-79, MI 42-43, SL 0.30-0.32, SI 73-75; yellow | 42A |
42A | ![]() |
. |
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South Africa - traegaordhi |
-- | ![]() |
South Africa - syntacta |
Maximum diameter of eye equal to or greater than width of scape | - | |
43 | Blackish or blackish-brown | 44 |
-- | No darker than brown | 45 |
44 | ![]() |
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Rwanda & Burundi - adrasora (part) |
-- | ![]() |
Cameroun - ettillax |
45 | ![]() |
East Africa - rukha (part) |
-- | ![]() |
46 |
Upper scrobe margins fringed by many inconspicuous narrowly spatulate to slender spoon-shaped hairs, similar in size to ground-pilosity of head | - | |
46 | ![]() |
. |
. | ![]() |
Seychelles - scotti |
-- | Mandibles & scapes shorter, MI 42-46 SI 73-82; petiole node in dorsal view broader than long | 47 |
47 | ![]() |
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West Africa and Congo basin into Burundi - hastyla |
-- | ![]() |
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Annobon I & Cameroun - zandala |
-- | ![]() |
Sao Thomé - sibyna |
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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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