The Ants of Africa
Genus Crematogaster
Crematogaster (Sphaerocrema) nigrans Forel - new subgenus placement

Crematogaster (Sphaerocrema) nigrans Forel - new subgenus placement

return to key {link to the Hymenoptera Name Server} Type location Zaïre (Cremastogaster foraminiceps Sant. r. nigrans n. st., Forel, 1915c: 338, worker & queen; raised to species by Santschi, 1921c: 117, misspelt nigricans), collected at St Gabriel, by Kohl - see below
worker and queen described (see Bolton, 1995) .

Forel' s (1915c) description of nigrans was -
WORKER: TL 3.5-4.2 mm; almost entirely black, with appendages dark brown, distinguishing it from Crematogaster foraminiceps and godfreyi [godefreyi a strips of Crematogaster sjostedti]. Petiole considerably wider with sides with anterior prominences well developed and rounded; wider than long. Postpetiole whole, as in Crematogaster kneri, without a longitudinal notch or posterior scalloping. Other aspects as in the type, propodeal spines a little narrower but as long as the type.
FEMALE: TL 8.6 mm; dark brown with funiculi, tarsi and sides of head and thorax reddish; propodeum with no more than obtuse tubercles; wings with rust tint; sculpture feebler than workers; hair pits on head much more effaced.
Collected from a hollow branch at St. Gabriel, Kisangani, Zaïre, by Kohl.

Santschi (1921c: 117), was writing about Crematogaster (Sphaerocrema) phoenix and had that as (my translation) "close to Cr. nigricans (= Cr. foraminiceps Sants st. nigricans Forel) but that, which may be a Sphaerocrema, has sculpture like that of foraminiceps, i.e. more feeble, more irregularly striate and the eyes set further forward.
Reading Forel's description, i.e. postpetiole whole as in kneri (also a Sphaerocrema), suggests this is misplaced as regards the subgenus but the petiole is divided, being so dark the angle of lighting can seem to hide the division.

{Crematogaster nigrans} The photomontage of the type worker is collated from

Oxford University Museum specimens

(previously identified by me as Cr. impressiceps)

Crematogaster (Crematogaster) nigrans
B Taylor det.
G Debout & A Dalecky
Cameroon 59

2°33.97' N
9°50.62' E
70 m from village; flat terrain, nest in a tree

{Crematogaster impressiceps major}The photomontage is of workers collected in Cameroun - south-western tropical coastal forest area between Edéa and Campo; McKey Wolbachia project (Cameroon 59). 

These are dimorphic. The head and body with dense fine longitudinal striations; the gaster is coriaceous and dull. The mandibles are coarsely striated, with puncturation close to the apical margin. Clypeus with fairly coarse striations. Head in full face view square but impressed behind and with a distinct medial smooth line. Eye flat and ovoid with a narrower lower apex. Antennal funiculus distinct - segments 2-7 resembling slightly elongate beads, distinct club with apical segment largest. Colour all over dark reddish-brown; antennal club pale yellow to near white. Dense decumbent pilosity all over, some fine erect hairs on anterior of head, pronotal angles and propodeum. In profile alitrunk domed, highest on mesonotum which has a distinct median carina, but in the form of a central line and not pronounced or protruding as in Atopogyne. Propodeal spines fairly short, acute and downturned at tips.

{Crematogaster nigrans minor}

© 2007, 2008, 2012, 2014, 2016 - Brian Taylor CBiol FRSB FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.