Bothroponera cavernosa

Wheeler (1922) and Wheeler and Wheeler (1971) reported that this species is usually found in colonies with a small number of individuals under stones in humid habitats and wet soils.

Identification
Joma and Mackay (2015) - The main distinguishing character of the worker B. cavernosa is the lack of foveolae on the second tergum of the gaster, which is rough and covered with short hairs. The worker is large (total length 12 mm). The anterior margin of the clypeus is “v” shaped and covered with fine striae. The anterior medial area of the clypeus is raised, covered with longitudinal striae and coarsely punctate on the sides with an incomplete clypeal carina. The mandibles are rough, moderately shiny and covered with striae. The scape extends slightly past the posterior lateral border of the head. The frontal lobes are sculptured and covered with striae. The frons is weakly striated. The propodeal spiracle is parallel to the posteropropodeal margin. The petiole is rounded and slightly narrowed anteriorly while it is vertical, slightly concave posteriorly (seen from above).

Bothroponera cavernosa is very easy to recognize as it is one of the five species in the Bothroponera pumicosa species complex with a specific form of the tergum of the 4th segment of the abdomen (2nd gastral tergite), that is rough and covered with short hairs. The other species are Bothroponera laevissima, Bothroponera aspera, Bothroponera umgodikulula and Bothroponera montivaga. The 2nd gastral segment of B. umgodikulula is mostly smooth and glossy, similar to that of B. aspera and B. laevissima, while in Bothroponera montivaga it is smooth with few shallow scattered punctures and is moderately shiny. The head shape of B. cavernosa, B. aspera, and B. laevissima is suborbicular while it is subquadrate in B. umgodikulula and B. montivaga. The other important differences between B. cavernosa, B. umgodikulula and B. montivaga compared to B. laevissima and B. aspera is that the body surface is heavily sculptured with foveolae in B. cavernosa, B. umgodikulula and B. montivaga while it is black, nearly smooth and shiny in B. laevissima and B. aspera with a few scattered punctures in B. aspera. Bothroponera cavernosa and B. umgodikulula both share all of the characteristics of B. montivaga except for the propodeal spiracle, which is obliquely vertical in B. montivaga and B. cavernosa while it is horizontal in B. umgodikulula. The anterior medial area of the clypeus is raised and does not form a complete clypeal carina in B. cavernosa (it is partially carinated). On the other hand, the anterior medial area of the clypeus of B. umgodikulula and B. montivaga is mostly smooth, and does not form carinae and in some specimens of B. montivaga the carina is only on the upper part of the anterior medial raised area of the clypeus while the lower part is smooth.

Distribution based on Regional Taxon Lists
Afrotropical Region: South Africa.

Nomenclature

 *  cavernosa. Ponera cavernosa Roger, 1860: 288 (w.) SOUTH AFRICA. Combination in Bothroponera: Mayr, 1862: 717; Wheeler, W.M. 1922a: 72; in Pachycondyla (Bothroponera): Emery, 1901a: 45; in Pachycondyla: Brown, in Bolton, 1995b: 304; in Bothroponera: Joma & Mackay, 2013: 3; Schmidt & Shattuck, 2014: 76. Current subspecies: nominal plus montivaga.

Worker
Joma and Mackay (2015) - (n=1), HL 3.00, HW 2.70, ML 1.45, EW 0.40, EL 0.45, SL 2.10, FL 3.60, WL 4.15, WPL 4.70, PL 1.15, PW 1.45, PH 1.75, CI 90, OI 17, MI 48.33, SI 78, PI 126.08. Head suborbiculate; mandibles covered with fine striae, with 7 teeth; clypeus covered with striae, anterior medial area raised to form discontinuous carina, coarsely punctate and rough on sides, clypeal length 2.35 mm; scape extends slightly past posterior border of head; maximum frontal lobe width 1.10 mm; length of malar space 0.55 mm; length from upper edge of eye to edge of posterior lobe 1.40 mm; pronotal shoulder rounded anteriorly, lower margin of pronotum straight with rounded anteroinferior pronotal process, pointed inferior pronotal process; basilar sclerite oval shaped; head mostly foveolate; antennae rough, scape covered with tiny shallow punctures, legs shiny; entire dorsum of mesosoma foveolate and rough; mesopleuron, lateropropodeum foveolate; metapleuron, lateropropodeum covered with coarse striae and grooves orientated perpendicular to posteropropodeal margin; dorsum of petiole and postpetiole coarsely foveolate and more punctate than other body parts; metapleuron and lateropropodeum covered with striae that have perpendicular orientation with posteropropodeal lateral margin; entire head, pronotum, mesonotum, propodeum, petiole, postpetiole covered with short erect golden hairs (up to 0.20 mm), on head, antennae, mandibles (0.03 - 0.08 mm in length), on pronotum, mesonotum, propodeum (up to 0.10 mm length), on petiole, postpetiole (0.13 - 0.15 mm in length); sternopostpetiolar process and 4th to 7th abdominal segments covered with relatively short (0.20 mm) erect golden hairs; head, mesosoma, petiole, 3rd - 7th abdominal segments black; mandibles, clypeus, appendages brownish red.

Type Material
Joma and Mackay (2015) - SOUTH AFRICA: Eastern Cape Province, Caffraria Drege, farm, 27°48’0’’ S; 25°7’0’’ E, Bothroponera cavernosa Roger, Mayr (1 w # 7165 GBIF-D/ FoCol 0955, holotype, MfN).