Aenictus rixator Forel, 1901

Gómez, Kiko, 2022, A revision of the Afrotropical species of the Dorylinae ant genus Aenictus (Hymenoptera: Formicidae) based on the worker caste, Belgian Journal of Entomology 124, pp. 1-86 : 47-48

Aenictus rixator Forel, 1901

( Figs 1 H , 30 A–D , 31 )

Aenictus rixator Forel, in EMERY, 1901: 48 (w.)

Holotype, SOUTH AFRICA: Natal VII-915 (Wroughton) (1w) MHNG [ CASENT0907030 , Material seen].

DIAGNOSIS. Its size, short scapes, overall aspect, colour and distribution could suggest the species in the mariae species complex as the closest relatives, but can be separated from them by the absence of a row of triangular teeth at the clypeus, the linear long mandibles (triangular in the mariae complex), with reduced dentition (three teeth against one apical and 4-8 denticles) and the presence of a clearly defined propodeal ridge.

DESCRIPTION ( Figs 1 H , 30 A–D ). WORKER. HL: 0.44; HW: 0.4; SL: 0.26; WL: 0.67; PL: 0.16; PH: 0.12; PPL: 0.12; PPH: 0.11; CS: 0.42; CI: 90; SIL: 60; SIW: 66; WL/HW: 166; PI: 133; PPI: 109 (n=1).

With the characters defined for the rixator group and: short scapes, slightly surpassing the middle of the head when laid back (SIL~60). Funicular segments wider than long, preapical subquadrate, apical more than twice longer than wide. Head longer than wide (CI~90), subrectangular, slightly wider at its middle, occipital line straight. Ventrolateral margin present but weak, not extending ventrally. Mandibles armed with three teeth.

Frontal ridges present, almost fused at its middle section and diverging again apically, its distal section elevated forming a low ridge overhanging from clypeus; parafrontal ridges present but very weak. Propodeal ridge present and clearly demarcated laterally and dorsally. Petiole with anterolateral, anterodorsal and dorsolateral carina present, the latter weak and discernible as a darker straight line in lateral and dorsal view reaching the spiracle; petiolar dome elliptical in lateral view, the anterior face straight sloping 45 degrees aprox. Posterior face vertical. Postpetiole subrectangular with vertical anterior and posterior face, the anterior angle with the dorsal surface obtuse and the posterior square, both rounded.

Subpetiolar process present but poorly developed, as a quarter of ellipse with its anterior face vertical and straight, without lamella, its size about the size of the prora.

Yellow to light brown, becoming yellowish red at the pronotum, sutures and patches of the head. Glassy smooth overall. Mesopleurae, pronotum and lateral zones of petiole and postpetiole faintly and patchy alutaceus to faintly reticulated.

Whole body covered with yellowish, fine setae, smaller than petiole height; semi erect to decumbent in mesosoma, petiole and postpetiole; decumbent to adpresed on scape, abdomen, and lateral margins of head. No pubescence noted.

OTHER MATERIAL EXAMINED. Known only from the Type specimen.

DISTRIBUTION. South Africa ( Fig. 31 ).

Figures

Fig. 1. Mandibular and clypeal shapes for the different species groups. A, gr. rotundatus (Aenictus guineensis, CASENT0876634). B, gr. koloi (Aenictus koloi, sp. nov., KGCOL00552). C, gr. eugenii (Aenictus eugenii, CASENT0235822). D, gr. eugenii (Aenictus mvuvii, sp. nov., CASENT0350555). E, gr. popeyei (Aenictus popeyei, sp. nov., CASENT0810234). F, gr. decolor (Aenictus decolor, CASENT0317077). G, gr. asantei (Aenictus asantei, NHMUK012849241). H, gr. rixator (Aenictus rixator, CASENT0907030).

Fig. 30. Aenictus rixator, holotype (CASENT0907030). A, head, dorsal view. B, habitus, lateral view. C, mesosoma, petiole and postpetiole, lateral view. D, mesosoma, petiole and postpetiole, dorsal view. E, mandibles and clypeus, dorsal view.

Fig. 31. Distribution of A. rixator.