|The Ants of
Genus Crematogaster - Subgenus Oxygyne
|Genus Crematogaster Introduction|
Diagnostic Features - Antennae 11-jointed, with 3-segmented club. Frontal carinae short. According to Santschi (1935) the workers are completely lacking in erect hairs on the dorsum of the body, save for some on the anterior of the head and on the femora.
Arnold (1920a: 542) gave a translation and comments, this is at .
Worker diagnosis of Crematogaster (Oxygyne) (Blainer, 2012)
1. In lateral view, median portion of clypeus more or less prominently convex and in full-face view medially protruding over mandibles.
2. Masticatory margin of mandibles with four teeth.
3. Fronto-clypeal suture [notch] impressed, often anterior portion of frons (above suture) transversely concave.
4. Head usually rounded and equally long as wide or slightly wider than long, cephalic index 0.97–1.18.
5. Promesonotal suture often complete and distinct.
6. Propodeal spines present.
7. Subpetiolar process absent.
8. Postpetiole with median impression.
9. Leg length variable, fairly long to moderately short, leg–body index 1.10–1.43, length of hind tibia 0.59–1.25 mm.
10. Body size highly variable, small to very large, head width 0.73–1.26 mm and Weber’s length 0.80–1.40 mm.
Blaimer, B. B. 2012. Untangling complex morphological variation: taxonomic revision of the subgenus Crematogaster (Oxygyne) in Madagascar, with insight into the evolution and biogeography of this enigmatic ant clade (Hymenoptera: Formicidae). Systematic Entomology, 37, 240–260.
Separation of species (based on historical descriptions)
|1||Propodeal spines short, reduced to sharp denticles||2|
|-||Propodeal spines relatively long and narrow||3|
|2||TL 2.9-3.3 mm; black-brown; shiny with sculpturation mostly of fine shagreening||Cameroun & Congo Basin - margaritae|
|--||TL 3.0-3.5 mm; black to dark brown; very finely reticulate, effaced in small individuals; head longer than wide rounded behind the eyes; antennal club indistinct 4-segmented; propodeum convex, spines, short and dentiform||Zimbabwe - donisthorpei|
|--||TL 2.9-3.4 mm; dull
black-brown; noticeably sculptured with short scapes, SI
||Cameroun & Congo Basin - brevarmata|
|.||Propodeal spines relatively long and narrow||.|
|3||TL 3.5-4.0 mm; black, moderately shining; head finely but densely striate, alitrunk more coarsely longitudinally striate; no pilosity but sparse fine yellowish pubescence; mandibles narrow but with four teeth; scape surpassing occiput by one-third its length, club distinctly 3-segmented; propodeal spines very acute, as long as dorsum of propodeum||South Africa - oscaris|
|--||Polished and shiny near black appearance||4|
|4||TL 3.0 mm; with overall fine spiculate sculpturation; gaster black, alitrunk and most of head brown-black, appendages reddish-brown; pronotum rounded; propodeal spines sharp||Cameroun & Congo Basin - trautweini|
|--||TL < 2.0 mm; black to dark brown; almost unsculptured, very shiny; HL = HW rounded behind the eyes; antennal club 4-segmented; propodeum convex, spines relatively long and sharp||Zaïre & South Africa - santschii|
© 2007, 2008, 2009, 2013, 2014, 2015 - Brian Taylor CBiol
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.