The Ants of Africa SUBFAMILY MYRMICINAE - Genus Pyramica - subgenus Smithistruma
Genus Pyramica

Subgenus Smithistruma Brown (1948: 104), includes previous Miccostruma Brown

In Tribe DACETINI.

Bolton (1999) made a radical revision and had Smithistruma as a junior synonym of Pyramica Roger. However, for convenience, I retained Smithistruma as a subgenus of Pyramica and so kept the key.

Diagnostic Features - Antennae 4-segmented (former Miccostruma) or 6-segmented, antennal scrobes present. Mandibles relatively short, subtriangular, serially dentate, and concealed for most of their length by the very well developed, anteriorly projecting clypeus, which is fringed anteriorly and laterally by flattened hairs. Dorsum of head with fine scattered punctures, hairs absent except on clypeus. Dorsum of alitrunk, pedicel and gaster mostly shiny, with small, widely spaced punctures. Base of first gastric tergite with longitudinal striae. Sutures absent from dorsal alitrunk. Propodeum bidentate. Spongiform appendages of pedicel well developed.

Brown (1953g) reviewed the then known African species, his key and descriptions are at .

Bolton (1983) described how all known Afrotropical species inhabit the leaf litter and topsoil layers, usually nesting directly into the ground or in rotten wood. The feeding habits of genus members were described by Déjean (1985), including Smithistruma truncatidens feeding on entomobryomorph collembolans. No species was regarded as common (Bolton, 1983) and most were represented by only a few collections and those were of few individual workers. Collecting efforts using Berlese and similar funnel extraction techniques had greatly increased the number of known species; for instance prior to Bolton's revisionary work only eight African species had been described, afterwards there were 35 separable species.

Smithistruma species C and Smithistruma species F, listed from cocoa leaf litter, and Smithistruma species E, listed from soil under Euphorbia, at the Mampong Cemetery farm in Ghana (Room, 1971), are clearly the three species emarginata, hensekta and sharra (see below) but they are not separable from the information given by Bolton (1983). A further, presently unnamed, species was found by Belshaw & Bolton (1994b), in Ghana, four workers collected from leaf litter, under cocoa at Effiduase and Bunso.

Bolton (2000: 269-271) separated these into the following species groups:

Key to subgenus Smithistruma workers from Africa (adapted from Bolton, 1983):

1	Antennae with 4 segments	2
--	Antennae with 6 segments	8
2	In full-face view, clypeus with a convex margin; pronotum with a median longitudinal carina and pronotal humeri each with a single flagellate hair	3
--	In full-face view, clypeus with a concave margin; pronotum without a median longitudinal carina and pronotal humeri without flagellate hairs	5
3	Clypeus broad, seen in full-face view expanded laterally far beyond the line of the outer margins of the closed mandibles; clypeus without hairs; TL 1.2-1.3 mm; uniform dull yellow to yellowish-brown	.
.		Ivory Coast, Ghana, Kenya, Tanzania, Zimbabwe & South Africa   - marginata
--	Clypeus narrow; edges more or less parallel with outer border of closed mandibles; dorsum of clypeus with abundant short curved hairs	4
4	Pronotum sharply marginate laterally, dorsum unsculptured; head relatively broad and scapes short; smaller, TL 1.7-1.8 mm, HL 0.42-0.46, HW 0.29-0.31, SL 0.18-0.20, PW 0.19-0.22; yellow to yellowish-brown	West Africa & Congo Basin - tacta
--	Pronotum not marginate, dorsum weakly sculptured; head relatively narrow and scapes long; larger, TL 3.0 mm, HL 0.74, HW 0.38, SL 0.44, PW 0.30; colour medium-brown	Cameroun - vodensa
5	Entire body with yellow and black tiger stripes; TL 2.0-2.2 mm	.
.		West Africa - tigrilla
--	Body uniformly coloured	6
6	In profile dorsum of head with a pair of short erect hairs; 4-segmented antennae; TL 1.7-1.8 mm; yellow to light brownish-yellow	.
.		Kenya, Tanzania & Angola - [alternative name maxillaris]  mandibularis
--	In profile dorsum of head without erect hairs	7
7	Anterior half of clypeus with a broad longitudinal depression filled with short scale-like hairs; subbasal elbows of scapes extensively developed and angular; pronotal dorsum with dense fine longitudinal rugulae or costulae; TL 2.0 mm; dark brown	Ivory Coast & Ghana - fulda
--	Anterior half of clypeus without an impression and that area without short scale-like hairs; subbasal elbow of scapes evenly rounded and not angled; pronotal dorsum smooth or faintly shagreened; TL 1.7-1.8 mm; dark yellow brown, extremities orange	West Africa - ninda
	Antenna 6-segmented	.
8	Dorsum of pronotum extremely coarsely sculptured with closely packed strong rugae or sulci giving a very coarse overall appearance	9
--	Dorsum of pronotum smooth to densely reticulate-punctate; may have feeble striate or very fine superficial rugulae	22
.	Dorsum of pronotum coarsely sculptured	.
9	Disc of postpetiole densely and strongly longitudinally costulate	10
--	Disc of postpetiole smooth and unsculptured, or no more than uneven or feebly punctate	12
10	Head very long and narrow (CI 54-58), antennal scapes long (SI 73-78); TL 2.4-2.6 mm; medium brown	Ivory Coast & Ghana - minkara
--	Head shorter and broader (CI > 60), antennal scapes shorter (SI 68-73)	11
11	Disc of postpetiole completely surrounded by dense spongiform tissue; transverse strips complete; pronotum dorsum coarsely longitudinally rugose; TL 2.4 mm; dark blackish-brown	.
.		West Africa - enkara
--	Disc of postpetiole with dense spongiform tissue only posteriorly and posterolaterally; transverse strips interrupted medially; pronotum dorsum irregularly reticulo-rugose; TL 2.4-2.6 mm; medium brown	Tanzania & Zimbabwe - nykara
12	With alitrunk in profile metanotal groove distinctly impressed	13
--	With alitrunk in profile metanotal groove not impressed, dorsal outline continuous	15
13	Posterior spongiform margin of postpetiole medially very deeply indented and reaching the margin of the disc; TL 3.0 mm; medium brown	Zaïre - weberi
--	Posterior spongiform margin of postpetiole medially very shallowly indented, clearly not reaching margin of disc	14
14	Dorsum of head with hairs strongly forward-arched so as to almost or actually touch surface; TL 2.6 mm; brown	Cameroun - mekaha
--	Dorsum of head, especially posterior half, with hairs which have the basal half to two-thirds erect then apices sharply angled forward; TL 2.5-2.6 mm; dark brown	Cameroun - kerasma
15	Dorsum of head behind clypeus with only fine soft looped or arched simple hairs	16
--	Dorsum of head behind clypeus usually with fine hairs plus long, stout conspicuous hairs similar to those on the clypeal dorsum	18
16	Posterior margin of clypeus without conspicuous erect hairs; TL 2.1 mm; orange-brown, gaster blackish-brown	West Africa and Congo Basin - malaplax
--	Posterior margin of clypeus with a transverse row of 4 or 6 straight erect, stout, hairs	17
17	Posterior margin of clypeus with a transverse row of 4 straight long, erect, stout, hairs	Zaïre & Burundi - piliversa
--	Posterior margin of clypeus with a transverse row of 6 straight shorter, erect, stout, hairs	Burundi - bellatrix
18	In profile the longest hairs on the clypeal dorsum (the rear-most row) no more than half the length of the hairs situated on the dorsum of head just behind the level of the eyes; TL 2.0-2.1 mm; medium-brown, gaster blackish-brown	Cameroun - placora
--	In profile both such sets of hairs of a similar length	19
19	Posterior spongiform strip of petiole very large, obviously densely spongiform not lamellar, thickness in dorsal view greater the exposed length of petiole node; TL 2.6-2.6 mm; dull yellowish-brown or lighter	Cameroun - arahana
--	Posterior spongiform strip of petiole narrow and lamellar, thickness clearly less than exposed length of petiole node	20
20	In posterior view head with long hairs seen as distinctly swollen apically, increasing in width from base to apex; TL 2.3 mm; medium- brown, gaster blackish	Angola - fenkara
--	In posterior view head with long hairs of uniform width throughout their length	21
21	Median indentation in posterior margin of spongiform strip of postpetiole not reaching sclerotised portion of disc; HW 0.50; TL 2.7-2.8 mm; dark brown, gaster blackish	Gabon - synkara
--	Median indentation in posterior margin of spongiform strip of postpetiole reaching sclerotised portion of disc; TL 2.1 mm; brown	Cameroun - tolomyla
	Dorsum of pronotum smooth or densely reticulo-punctate	.
22	Anterior margin of clypeus solely with a few fine curved simple hairs; scape bearing straight hairs that project at right-angles; eye of 1-2 ommatidia and difficult to see; TL 2.2 mm, HL 0.54, HW 0.40, SL 0.27, PW 0.24 (no illustrations available)	South Africa - mira
--	Scape lacking straight hairs; eye larger 4 plus ommatidia	23
23	Head in full face view with a near straight occiput and straight sides; appressed hairs variably thick but straight sided; clypeus with spatulate hairs	24
--	Head in full face view variable, most with arcuate sides; appressed hairs fine or spatulate; clypeus with filiform or clavate hairs	25
24	Clypeus with narrow indistinct spatulate hairs; occipital lobe without a laterally projecting flagellate hair; TL 1.9-2.0 mm, HL 0.47-0.51, HW 0.33-0.34, SL 0.25-0.27, PW 0.22-0.25	South Africa - agnosta
--	Clypeus with broad spatulate hairs; occipital lobe with a laterally projecting flagellate hair; TL 2.1 mm, HL 0.53, HW 0.36, SL 0.27, PW 0.25	South Africa - dictynna
25	Pronotal humeri each with a long flagellate hair, the pronotum dorsum with a median ridge; leading edges of scapes without anteriorly projecting long hairs; anterior clypeal margin convex and lacking a lateral fringe of spatulate hairs	26
	Pronotal humeri without long flagellate hairs, the pronotum dorsum without a median ridge; leading edges of scapes with anteriorly projecting long hairs; anterior clypeal margin straight to concave and with a continuous fringe of spatulate hairs	30
26	In profile clypeal dorsum without hairs; in full face view anterior clypeal margin broadly convex; sides of clypeus near parallel; TL 2.1-2.3 mm; glossy light brown	Zimbabwe - rusta
--	In profile clypeal dorsum with weakly clavate posteriorly curved hairs hairs; in full face view anterior clypeal margin narrowly convex; sides of clypeus forming a line with the mandibles	27
27	Head in full-face view without laterally projecting flagellate hairs	28
--	Head in full-face view with laterally projecting flagellate hairs	29
28	Elongated hairs on gaster restricted to a transverse row of four close to the base; flagellate hairs absent from upper scrobe margins; TL 1.9 mm; dull glossy yellow	.
.		South Africa - anarta
--	Elongated hairs on gaster numerbering 12 or more and not confined to close to the base; 2-3 flagellate hairs on each upper scrobe margin; TL 1.8-2.0 mm, HL 0.48-0.51, HW 0.32-0.35, SL 0.24-0.28, PW 0.20-0.22 (no available illustration)	South Africa - ogyga
29	Elongated hairs on gaster restricted to a transverse row of four close to the base; flagellate hairs absent from upper scrobe margins; TL 1.9 mm; dull glossy yellow	South Africa - sardonica
--	Elongated hairs on gaster numbering 12 or more and not confined to close to the base; 2-3 flagellate hairs on each upper scrobe margin; TL 1.9-2.1 mm; glossy medium brown	South Africa & Lesotho - oxysma
30	Mandibles with 16-17 teeth of which the 7th or 8th from the base is by far the largest; TL 2.5-2.6 mm; black	31
--	Mandibles with 12 teeth of which one of the basal row of five is the largest	32
31	TL 2.5-2.6 mm; black	Cameroun - terroni
--	TL 3.4-3.6, HW 0.66-0.68; head extremely flattened dorsoventrally; overall finely punctate-granular no images available)	Cameroun & Zaire - tethepa
.	Mandibles with 12 teeth of which one of the basal row of five is the largest	.
32	In full-face view the head with entire dorsum with large flattened, very broadly scale-like to suborbicular hairs	33
--	In full-face view head without such hairs, or if present the hairs in one or two clear transverse bands	34
33	Postpetiole and first gastral tergite with erect hairs, CI 63-67, no or few scale-like hairs on disc of postpetiole; TL 1.9-2.1 mm; medium to light brown	West Africa & Congo Basin - cavinasis
--	Postpetiole and first gastral tergite without erect hairs, CI 56-63, scale-like hairs sparse but obvious on disc of postpetiole; TL 2.0-2.2 mm; medium to dark brown	West Africa - sharra
34	First gastral tergite without standing hairs	35
--	First gastral tergite with standing hairs numerous, or at least single basal and apical pairs	36
35	Dorsum of head with a transverse band of broadly scale-like to suborbicular hairs just forward of occipital margin; TL 2.1 mm	.
.		Ghana - chyatha
--	Dorsum of head without hairs other than fringe around clypeal margin; TL 2.1-2.2 mm; uniform light brown	.
.		Ivory Coast - impidora
36	Base of first gastral tergite sharply impressed medially, sclerite with a dented appearance, scapes relatively long (SI 72-80); TL 2.4-2.8 mm; yellow to medium brown, gaster may be darker	37
--	Base of first gastral tergite not impressed medially, scapes shorter (SI 58-67)	41
37	Mesonotum dorsum with 3-4 pairs of straight or slightly curved erect bristle-like simple or slightly thickened hairs	38
--	Pronotum with and sides of head with small spoon-shaped hairs	40
38	Pronotum with erect simple hairs as on mesonotum; pronotal humerus with a single laterally projecting elongate simple hair; dorso-lateral margin of head behind the eye with 5-6 projecting curved hairs that are blunt or feebly thickened; promesonotum lacking in spoon-shaped hairs; TL 2.3 mm, HL 0.66, HW 0.41, SL 0.31, PW 0.26 - no illustrations available	South Africa - noara
--	Pronotum with and sides of head with small spoon-shaped hairs	39
39	Propodeum near smooth; simple curved erect hairs numerous on head and contrasting with spoon-shaped ground pilosity; TL 2.3-2.5 mm, HL 0.64-0.70, HW 0.38-0.41, SL 0.30-0.32, PW 0.25-0.28	West Africa - exunca
--	Alitrunk generally weakly sculptured; head without erect hairs; pronotum dorsum with solely distinct spoon-shaped hairs; mesonotum with 3-4 pairs of long curved hairs; TL 2.3-2.5 mm, HL 0.62-0.67, HW 0.38-0.41, SL 0.29-0.31, PW 0.24-0.2	Zimbabwe & South Africa - robertsoni
40	Alitrunk wholly but variably reticulate-punctate; TL 2.4-2.8 mm, HL 0.64-0.70, HW 0.39-0.42, SL 0.29-0.32, PW 0.24-0.28 ;	.
.		South Africa - emarginata
--	Alitrunk largely smooth and shiny; head and alitrunk medium brown, gaster contrastingly darker brown	Burundi - subsessa
.	Base of first gastral tergite not impressed medially, scapes shorter (SI 58-67)	.
41	Pronotal disc glassy smooth between widely scattered small punctures; TL 2.2-2.3 mm; light glossy brown	Rwanda - gatuda
--	Pronotal disc uniformly closely sculptured, subopaque to opaque	42
42	Dorsum of head with a transverse band of broadly scale-like hairs just forward of occipital margin plus another just behind the level of the frontal lobes; TL 2.5 mm; light brown	.
.		Cameroun - behasyla
--	Dorsum of head without two bands of scale-like hairs	43
43	In full face view head with conspicuous projecting hairs behind the level of the eyes	44
--	In full face view head without conspicuous projecting hairs behind the level of the eyes	45
44	Anterior clypeal margin transverse; dorsal alitrunk with 6-7 pairs of erect hairs; TL 2.0-2.1 mm; uniform dull yellow	West Africa & Congo Basin - hensekta
--	Pronotum dorsum punctate; TL 2.4-3.0 mm; dull yellow to light yellowish-brown (j. syn. dendexa)	.
.		Cameroun to East Africa - truncatidens
45	Postpetiole dorsum finely longitudinally costulate; infradental lamella of propodeum reduced to a simple flange; TL 2.6-2.7 mm; dark brown	Rwanda - datissa
--	Postpetiole dorsum wholly smooth; infradental lamella of propodeum broad and conspicuous; basal lamella of mandible an evenly rounded broad lobe; TL 2.2-2.4 mm; dark brown to blackish-brown	.
.		South Africa - transversa

MYRMICINAE Introduction

© 2007, 2013, 2015 - Brian Taylor CBiol FSB FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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