[29] Anochetus africanus

The group of A. africanus includes fairly large-sized (worker HL + ML 2.15-2.60 mm) species with frontal striation fine, straight, regular, and reaching to or very nearly to the nuchal carina; eyes fairly large (EL 0.18-0.28 mm), but usually not as big relatively as in bequaerti, pellucidus, or sedilloti (for examples); gastric dorsum completely smooth and shining, with only scattered piligerous punctures, thus excluding the closely related bequaerti complex. Second funicular segment shorter than third, not very much longer than broad (L <2W).

I include in the africanus group 4 nominal species (with their synonyms): africanus, obscuratus, madagascarensis and naialensis. In general, africanus has the pronotum densely sculptured and opaque to weakly shining, natalensis has the pronotum strongly shining, but with faint discal striato-punctulation, and obscuratus and madagascarensis have the pronotum smooth and shining, with only fine, scattered punctures. The oft-collected A. africanus appears to range throughout the forested regions of West and Central Africa as far south as northern Angola (gallery forest of R. Kahingo, 7.39 S, 20.51 E, Mwaoka) and the Kasai River area of southern Zaire; east into Uganda (Mabira Forest, G. Anold) and the Imatong Mts. of southernmost Sudan (N. A. Weber); and northwest to Liberia (Gibi, W. M. Mann) at least. The pronotum is covered with sculpture, ranging from wavy-costulate to striate-punctulate in an inverted U- or V-shaped or oval pattern; in some samples (e.g., Cameroun and 12 miles of Kasaji, Zaire, E. S. Ross and R. E. Leech) the pronotal sculpture is weak, and the surface is shining and much more nearly smooth than usual.

The more lightly-sculptured East African counterpart, A. obscuratus, is poorly known, and is only barely distinguishable from the island isolate, A. madagascarensis. These two may in fact be only slight geographical variants of one species. A. obscuratus has the posterior truncal dorsum even less strongly sculptured (more strongly shining) than in the 8 Malagasy locality samples now available, though direct comparison is needed to appreciate the distinction. A. obscuratus samples are also much less uniform; var. ustus has the posterior trunk almost completely smooth and shining, an extreme of the trend in obscuratus. The samples of A. obscuratus I have seen are the type of schoutedeni from Dumbi, Kasai district, Zaire; the type worker of ustus, from Makumbi in the same district; the types of A. obscuratus, from Kiboschi, Kilimanjaro, Tanganyka; and a series of 6 workers and alate queens from 11 miles S. Maktau, Teita Prov., Kenya, E. S. Ross and R. E. Leech. A worker chosen at random from the last sample has HL + ML = 2.55 mm, while the eye is 0.26 mm long.

A. natalensis is based on the type series, from Pietermaritzburg, Natal, and I know of no other samples. It is intermediate in sculpture between the more lightly-sculptured africanus mentioned above (Kasaji, Cameroun) and obscuratus, b,ut the eyes are a little larger than in either relative: EL 0.28 mm in a worker in which HL + ML = 2.25. The petiolar node is a bit sharper at the summit in side view than in most africanus samples. This species may just be a slightly extreme variant of africanus or obscuratus, or it may really represent an extralimita!, independent species. We need more material of the complex, especially from Rhodesia, Zambia and Mozambique, in order to understand what natalensis is.

The relationship between africanus and obscuratus is still open to question, although it does appear that the two remain reasonably distinct in areas (such as southern Zaire and Uganda) where they may be sympatric or nearly so. Otherwise, we could be dealing with conspecific forest and savanna ecotypes that intergrade sharply in ecotonal districts, a possible interpretation also of the inermis complex [40].

The types of A. pasteuri are large examples of africanus, the worker with eyes no larger (EL 0.25) than in members of the latter species of the same size (EL 0.25-0.26). The other characters cited by Santschi in his comparison with africanus are all ones of slight degree and variable in the africanus material available.