SUBFAMILY MYRMICINAE - Genus Pyramica - subgenus Serrastruma
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The Ants of
Africa SUBFAMILY MYRMICINAE - Genus Pyramica - subgenus Serrastruma |
| Genus Pyramica |
Diagnostic Features - Mandibles elongate, triangular, and serially denticulate, with more than 20 denticulae, the basal 4-8 possibly much bigger than the others. Antennae 6-segmented, second and third funicular segments reduced. Antennal scrobes present. Promesonotal suture may be present as a weak impression. Pronotum may be differently sculptured to the mesonotum. Metanotal groove impressed, propodeum armed with a pair of teeth, which may be reduced. Spongiform appendage of pedicel usually reduced. All species golden yellow.
An early key to African and Madagascar dacetines is that of
Santschi (1913b); that, with modern annotation, is 
.
Genus first separated by Brown (1948e), as a subgenus of Smithistruma, and raised to full genus by Brown (1949d). Subsequently Brown (1952e) reviewed many of the then known specimens, but Bolton (1983) completely revised the genus with a number of synonymies and several new species being defined. Bolton (1999) has made a radical revision and now has Serrastruma as a junior synonym of Pyramica Roger.
For convenience, I have retained Serrastruma as a subgenus of Pyramica and, so, have kept the key.
All members of the subgenus are from sub-Saharan Africa, with ludovici and simoni having spread to Madagascar and Mauritius.
Bolton (2000: 269 ff) had the following species-group (wholly
matching the subgenus, so why Bolton felt a species-group name should
be erected is curious): lujae-group:
bequaerti, concolor, depilosa (sp.n.), dotaja, geoterra, inquilina, lucifuga (sp.n.), ludovici, lujae, maynei, miccata, serrula, simoni and sulumana. I add braeti and mckeyi.
Key to workers of African species (adapted from Bolton, 1983; and Bolton, 2000: 272; couplets 1 -> 9 -> 10 ff to 22):
| ¤ |  Known only from inquiline queens |
Zaïre (Ruwenzori) - inquilina |
| 1 |  With the head in
full-face
view the upper scrobe margin just behind the level of the eye without a
projecting long hair (Bolton 2000 couplet 11) |
2 |
| -- |  With the head in
full-face
view the upper scrobe margin just behind the level of the eye with a
projecting long flagellate or simple fine hair (Bolton 2000 couplet 17) |
9 |
| 2 | Dorsum of head and alitrunk with very conspicuous thickly spatulate to scale-like coarse ground-pilosity | 3 |
| -- | Dorsum of head and alitrunk with inconspicuous slender, very narrowly spatulate ground-pilosity | 6 |
| . | Dorsum of head and alitrunk with very conspicuous dense, thickly spatulate to scale-like coarse ground-pilosity; antennal scapes relatively short SI 73-83 | . |
| 3 | Dorsal alitrunk sculptured; sides of head not broadly convex posteriorly; TL 2.3-3.0 mm; dull brownish-yellow to mid-brown | 4 |
| -- | Dorsal alitrunk glassy smooth; sides of head broadly convex posteriorly; TL 2.6-2.7 mm; glossy brown | 5 |
| 4 |  Occiput in profile
with 2-3 pairs of stout erect hairs; pronotal dorsum densely and
sharply costulate (striate?); ground pilosity of numerous curved,
broadly spatulate and conspicuous hairs; upper margin of scrobe well
defined; TL 2.3-3.0 mm, HL 0.52-0.66,
HW 0.44-0.54, SL 0.34-0.42, PW 0.31-0.41; dull
brownish-yellow to mid-brown |
. |
| . |  |
Pan-African - maynei |
| -- |
 Occiput in profile with a single
pair of stout erect hairs; pronotal
dorsum sparsely and weakly costulate (striate?); ground pilosity of
sparse inconspicuous, narrowly spatulate hairs;upper margin of scrobe
weak and incomplete; TL 2.4-2.6 mm, HL 0.57-0.60, HW 0.46-0.48, SL
0.41-0,43, PW 0.36-0.38 |
Cameroun & Gabon - depilosa |
| 5 |  Mesonotum dorsum without raised and prominent
anterolateral angles;
mesonotum and dorsum of propodeum finely reticulate-punctata not as
smooth and shiny as pronotum; head narrower and scape longer, CI 74-75,
SI 86-89; TL 2.0 mm, HL 0.48-0.50, HW 0.36-0.37, SL
0.32, PW 0.27-0.28 |
Cameroun & Kenya - lucifuga |
| -- |  Mesonotum dorsum with
raised and prominent anterolateral angles; mesonotum and dorsum of
propodeum as smooth and shiny as pronotum; head broader and scape
shorter, CI 90, SI 73-74; TL 2.6-2.7 mm, HL 0.58-0.60, HW 0.52-0.54, SL
0.38-0.40, PW 0.34-0.37; glossy
brown |
. |
| . |  |
Cameroun & Kenya - geoterra |
| . | Dorsum of head and alitrunk with inconspicuous slender, very narrowly spatulate ground-pilosity | . |
| 6 | Pronotal humeri each with a long, fine flagellate hair | 7 |
| -- | Pronotal humeri without a long, fine flagellate hair | 8 |
| 7 |  Leading
edges of scapes with fine simple outcurved short hairs; mandibles
longer, basal 4-5 denticles not much enlarged; metanotal groove not
impressed; TL 2.0 mm; pale yellow |
Cameroun - sulumana |
| -- |  Mandibles and scapes
relatively short; occiput with a transverse row of 2 or 4 erect hairs
on the posterior margin and an anterior pair of hairs |
Cameroun & Zaire - bequaerti |
| -- |  Dorsal alitrunk weakly
sculptured; sides of head broadly convex posteriorly; TL 1.96 mm, HL
0.45, HW 0.36, CI 90, SL 0.26, SI 68, PW0.25; orange yellow |
Cameroun - new species - mckeyi |
| -- |  Leading edges of
scapes with
fine simple outcurved short hairs; mandibles longer, basal 4-5
denticles not much enlarged; metanotal groove not impressed; TL 1.5 mm;
pale yellow (postdates Bolton 2000) |
Cameroun - Pyramica nsp CASENT0414575 |
| . | Pronotal humeri without a long, fine flagellate hair | . |
| 8 |  Pronotal humeri each
with a
short, stout clavate hair; leading edges of scapes with projecting
short clavate hairs; mandibles shorter, basal 4-5 denticles
conspicuously enlarged; metanotal groove not impressed; TL 1.9-2.3 mm;
dull yellow to yellowish-brown |
. |
| . |  |
Ghana - miccata |
| -- |  TL
1.8 mm; HW 0.38, HL 0.48, CI 87, SL 0.26, SI 65, PW 0.27 dull brown |
Congo - new species - braeti |
 |
With the head in full-face view the upper scrobe margin just behind the level of the eye with a projecting long flagellate or simple fine hair | . |
| 9 | Main sculpture of dorsal pronotum dense reticulate-punctation, with or without overlaying but secondary costulate or striate sculpture | 10 |
| -- |  Main
sculpture of dorsal pronotum of
longitudinal to oblique striae or costulae, or smooth and unsculptured;
secondary punctate sculpture usually absent or no more than feeble |
13 |
| 10 |  In
full-face view, the mandibles with enlarged
basal denticles, usually distinctly so; TL 1.9-3.0 mm; yellow to
mid-brown |
. |
| . |  |
Pan-African - ludovici (part) |
| -- | Basal series of mandibular denticles not markedly enlarged | 11 |
| 11 |  Mesonotum with 3-4
pairs of
short, erect slender hairs, posterior pair close to metanotal groove;
ground pilosity of promesonotum strong and conspicuous in profile;
punctate sculpture of head and alitrunk strong and sharply defined; TL
1.9-2.3 mm; dull yellow to yellowish-brown |
. |
| . |  |
Pan-African - serrula |
| -- | Mesonotum usually with a single anterior pair of apically thickened to strongly clavate hairs; rarely a second pair present, if so close to first pair; ground pilosity of promesonotum feeble and inconspicuous; punctate sculpture on head and alitrunk usually fine | 12 |
| 12 |  Dorsum of head behind
highest point of vertex with 4 relatively slender simple hairs, plus a
further pair forward of vertex high-point; in full-face view the upper
scrobe margins are not indented at the site of the projecting hair;
postpetiole with more than one pair of hairs; TL 2.2-3.3 mm; yellow to
medium brown |
. |
| . |  |
Pan-African - lujae |
| -- |  Only 2-4 hairs behind
highest point of vertex of head dorsum; these hairs thickened apically
to clavate; in full-face view upper scrobe margins usually
conspicuously indented at site of projecting hair; postpetiole with
only a single pair of standing hairs; TL 2.0-2.2 mm; yellow to
yellowish-brown |
. |
| . |  |
Pan-African - concolor |
|
Main sculpture of dorsal pronotum of longitudinal to oblique striae or costulae, or smooth and unsculptured; secondary punctate sculpture usually absent or no more than feeble | . |
| 13 |  A pair of very long
flagellate hairs on the pronotal humeri and pronotum; first gastral
tergite with only a single pair of long simple hairs; TL 2.3-2.5 mm;
blackish-brown to jet black |
|
| . |  |
Cameroun & Gabon - dotaja |
| -- | Pronotal humeri but not mesonotum with flagellate hairs; mesonotum usually with a single pair (rarely 2 pairs) of stout hairs, thickened or clavate apically; first gastral tergite with thickened or clavate hairs | 14 |
| 14 | In
full-face view, the mandibles with enlarged
basal denticles, usually distinctly so; TL 1.9-3.0 mm; yellow to
mid-brown |
. |
| . | |
Pan-African - ludovici (part) |
| -- |  Mandible
without enlarged denticles; in profile
postpetiole with ventral spongiform lobe greater in area than the
exposed area of postpetiole; TL 2.4-3.0 mm; golden yellow |
. |
| . |  |
Pan-African - simoni |
 |
MYRMICINAE Introduction |
© 2007, 2008, 2009, 2010, 2011, 2013, 2015 - Brian
Taylor CBiol FSB FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K. |
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