Bothroponera soror

Known from tropical forest and acacia woodland habitats.

Identification
Worker Similar characters as the other Bothroponera sulcata species complex species with some exceptions. The mandibles are smooth, shiny and sparsely punctate, narrowed and have about 6-8 teeth. The compound eyes are relatively large. The malar space length is 0.25 - 0.35 mm while the area from upper edge of eye to the upper margin of the posterior lateral corner of head is 0.95 mm.

Most of the specimen is roughly sculptured with a few scattered punctures. The second gastral segment (fourth abdominal segment) is mostly shiny and slightly roughened (less sculptured and without punctures). The clypeus, legs and antennae are moderately shiny. The pronotal humerus is rounded anteriorly, the lower margin is straight with a rounded anteroinferior pronotal process and a pointed inferior pronotal process. The propodeum is quadrate (lateral view), the dorsopropodeum forms a curve with the posteropropodeum. The posteropropodeal lateral margins form granulated, carinated and sharp margins. The posteropropodeum is slightly concave (side view). From a dorsal view, the posterior edge of the dorsopropodeum is slightly curved with a depression where it joins with the posteropropodeum.

Most of the body is covered with a few moderately short erect scattered hairs, except for the head which is bare with a few short erect hairs dorsally.

Most of the ant is dark brown.

The worker of Bothroponera soror is characterized by distinguishable traits among members of the B. sulcata species complex. The posteropropodeum in B. soror is strongly sloping posteriorly to form a semi-vertical face that is flat (side view) for the reception of the anterior face of the petiole. This character in B. soror is similar to that in Bothroponera ancilla, Bothroponera picardi, Bothroponera silvestrii, Bothroponera ryderae and Bothroponera pilosuperficia. On the contrary, the posteropropodeum is flat, not concave as in B. silvestrii, Bothroponera crassa, Bothroponera ilgii and Bothroponera notaula, and forms an obtuse angle with the dorsopropodeum. In Bothroponera kruegeri, the dorsopropodeum is broadly curved posteriorly to form the posteropropodeum that slopes gradually to the insertion point of the petiole between the propodeal lobes.

The clypeus of B. soror forms a raised anterior medial area that has a longitudinal smooth and / or striate shiny strip similar to that of B. ancilla. In some specimens, this area has a weak groove that forms a slight depression sometimes covered with fine striae. The similar clypeal structure can be found in B. crassa, B. ilgii, B. kruegeri, B. picardi, B. notaula, B. ryderae, B. pilosuperficia and B. silvestrii. In B. crassa the anterior medial margin of the clypeus is convex with a smooth shiny medial raised area, sometimes with a slight groove. In B. ilgii, the anterior medial margin of the clypeus is convex with a medial raised area that forms a longitudinal shiny groove on the raised area that is sculptured and somewhat striated on the upper portion. The raised area in B. ilgii forms a groove that sometimes has a straight flat strip or a slight depression. In B. silvestrii, the medial raised area of the clypeus forms a posterior sculptured area while the anterior part forms a triangular smooth area without a groove. In B. kruegeri, the clypeus has a medial raised area that forms a sculptured upper part and flat or mostly raised area on the lower part. In B. picardi, the anterior medial margin of the clypeus forms a shiny groove on the medial raised area. In B. silvestrii, the clypeus has a single medial raised area that forms a smooth shiny longitudinal groove, which is similar to B. picardi and wide, slightly deeper in B. notaula. In B. ryderae there are fine striae on the upper portion and sides of the medial raised area of the clypeus, with a slight depression on the lower part. In B. pilosuperficia, the medial raised area is smooth and shiny but without a groove.

Bothroponera soror is smaller (total length 8.65- 11.10 mm) than B. kruegeri (11.75 - 12.55 mm), but overlaps with B. ilgii (8.35 - 9.40 mm), B. ancilla (6.75 - 8.90 mm), B. notaula (7.60 mm) and B. pilosuperficia (7.50 - 9.00 mm). On the other hand, the total length of Bothroponera soror is larger than that of B. picardi (6.30 - 6.50 mm), B. silvestrii (5.25 - 7.05 mm), B. crassa (6.00 - 8.80 mm) and B. ryderae (6.55 - 7.20 mm).

Queen The female of B. soror is similar to the worker. The total length of the B. soror female (8.60 - 10.10 mm) overlaps that of the worker. The head (excluding mandibles) is subquadrate, excluding the mandibles. The scape extends slightly past the posterior lateral corner of the head. The mandibles are smooth, narrowed and with 7 teeth.

The pronotum is rounded anteriorly, the lower margin is straight (seen from side view), the anterior end of the margin is strongly rounded, but the posterior end forms a sharp pointed tip. The scutum is as wide anteriorly as the pronotum (1.45 mm) and narrowed posteriorly to reach the same width as the scutellum (1.30 mm). The metanotum is slightly elevated, narrowed, well separated between the dorsopropodeum and scutellum. The posterolateral edges of posteropropodeum are angulate. The posteropropodeum is vertical and concave, structured to fit the anterior face of the petiole (the shape corresponds to the form of the petiole). The mesopleuron is divided by the anapleural sulcus to form the lower katepisternum and upper anepisternum. The meso-metapleural suture is well defined. The metanepisternum is poorly developed. The katepisternum is separated from the lateropropodeum by a well-defined suture. The petiolar level is slightly higher than the postpetiole and the dorsopropodeum. The postpetiole and rest of gaster are larger than the mesosoma.

Most surfaces are covered with moderately long erect hairs. Hairs on the second gastral tergite are less dense and shorter than those the postpetiole (less than 0.30 mm). Hairs on pygidium are denser than those on the postpetiole and longer than 0.30 mm. The mandibles are covered with moderately long hairs (0.15 - mm).

The head, pronotum, propodeum, petiole and postpetiole are light brown, but the scutum, scutellum and metanotum are dark brown. The legs, scape and the mandibles are pale brown.

The female of Bothroponera soror is similar in size or slightly smaller than the worker (total length 8.60 - 10.10 mm for the female, 8.65 - 11.10 for the worker). The B. soror female can only be compared with the female of B. pilosuperficia in the B. sulcata species complex, as the others are unknown or not available.

The major variations between the two females (B. soror and B. pilosuperficia) are the form of the hairs and the shape of the anterior medial area of the clypeus. The clypeus is convex in both species, but the anterior medial area of the clypeus forms a narrow, shiny, longitudinal slight depression that has fine striae in B. soror, but this character is with a slight groove and lacking striae in B. pilosuperficia. The entire surface including the head is covered with moderately long, abundant, silver erect hairs in B. pilosuperficia while the hairs are less abundant and lacking on the head except for some erect scattered short hairs on dorsum of the head in B. soror.

Male The ocelli and mandibles are relatively small. Notauli are present on dorsum of the scutum, but do not meet at a point. The metanotum is elevated between scutellum and the propodeum, but without a carina. The metanepisternum is distinguished from mesopleuron while the metakatepisternum is narrowed and poorly developed. The propodeum gradually slopes posteriorly to reach the insertion of the petiole. The petiole is small and rounded dorsally. Most of the ant is roughly sculptured, 4th to 7th abdominal segments are smooth and shiny.

The entire body is covered with fine short (length less than 0.05 mm) dense hairs, moderately long hairs are scattered on most surfaces.

The surfaces are light to dark brown.

The male of B. soror can be separated from the males of B. crassa, B. kruegeri, B. silvestrii, B. notaula, B. ryderae and B. ilgii by the total length, presence or absence of notauli, sculpture, ocellar size and the propodeal shape. The total length of B. soror is larger (6.45 - 7.45 mm) than that of B. silvestrii (4.70 - 5.10 mm), which easily separates the two species. Bothroponera kruegeri can also be excluded from the comparison because it has the largest total length (10.25 mm) among the B. sulcata species complex members. The other species include B. crassa (5.90 - 7.50 mm), B. notaula (5.60 - 7.90 mm) and B. ryderae overlapping in total length with B. soror. The medial ocellus is small in B. soror (0.12 - 0.15 mm), resembling that of B. silvestrii (0.12 -0.13 mm), B. ryderae (0.15 mm) and the type specimen of B. ilgii (0.17 mm); in comparison, the medial ocellus is large in B. crassa (0.22 - 0.25 mm), B. kruegeri (0.35 mm) and B. notaula (0.22 - 0.23 mm). The notauli are present but do not meet on the dorsum of the scutum in B. soror, B. notaula, B. ryderae and B. silvestrii. The notauli are not present or poorly developed in B. crassa, B. ilgii and B. kruegeri. The dorsopropodeum is strongly curved posteriorly in B. soror, whereas it slopes gradually to the posteropropodeum in B. crassa, B. ilgii, B. notaula, B. ryderae, B. kruegeri and B. silvestrii.

Distribution based on Regional Taxon Lists
Afrotropical Region: Angola, Burundi, Cameroun, Democratic Republic of Congo, Ethiopia , Gabon, Ghana, Guinea , Ivory Coast, Kenya, Mozambique, Sudan, Uganda, United Republic of Tanzania, Zimbabwe.

Nomenclature

 *  soror. Ponera (Bothroponera) soror Emery, 1899e: 472 (w.q.) CAMEROUN.
 * Menozzi, in Eidmann, 1944: 432 (m.l.); Wheeler, G.C. & Wheeler, J. 1952c: 623 (l.); Wheeler, G.C. & Wheeler, J. 1971c: 390 (l.).
 * Combination in Pachycondyla (Bothroponera): Emery, 1901a: 46.
 * Combination in Bothroponera: Wheeler, W.M. 1922a: 72.
 * Combination in Pachycondyla: Brown, in Bolton, 1995b: 309.
 * Combination in Bothroponera: Schmidt & Shattuck, 2014: 77.
 * Senior synonym of lamottei, suturalis: Joma & Mackay, 2017: 43.
 * See also: Arnold, 1915: 59; Wheeler, W.M. 1922a: 72; Joma & Mackay, 2017: 43.
 * lamottei. Bothroponera lamottei Bernard, 1953b: 188 (w.) GUINEA.
 * Combination in Pachycondyla: Brown, in Bolton, 1995b: 306.
 * Combination in Bothroponera: Schmidt & Shattuck, 2014: 77.
 * Junior synonym of soror: Joma & Mackay, 2017: 43.
 * suturalis. Pachycondyla (Bothroponera) soror subsp. suturalis Forel, 1907c: 133 (w.) ETHIOPIA.
 * Combination in Bothroponera: Schmidt & Shattuck, 2014: 77.
 * Junior synonym of soror: Joma & Mackay, 2017: 43.

Description
Joma and Mackay (2017):

Worker
(n=40), HL 1.70 - 1.90, HW 1.50 - 1.65, ML 1.10 - 2.10, EW 0.25 - 0.30, EL 0.30 - 0.40, SL 1.45 - 1.70, FL 2.15 - 2.55, WL 2.65 - 3.00, WPL 3.35 - 3.70, PL 0.75 - 1.75, PW 0.90 - 1.00, PH 1.10 - 1.25, CI 86.84 - 88.23, OI 20.00 - 24.24, Mandl 64.70 - 110.52, SI 96.66 - 103.03, Peti 57.14 - 120.00. B. suturalis measurements: HL 1.75, HW 1.50- 1.55, ML 1.05- 1.10, EW 0.30 -0.40, EL 0.35 - 0.50, SL 1 .40 - 1 .45, FL 2.25 - 2.35, WL 2.65 – 2.70, WPL 3.30, PL 0.70, PW 0.85 – 0.95,, PH 1.15 - 1.25, CI 85.71 - 88.57, OI 23.33 - 32.25, Mandl 60.00 - 62.85, SI 93.33 - 93.54, Peti 121.42 - 135.71. B. lamottei measurements: HL 1.75 - 1.85, HW 1.55- 1.60, ML 0.90 - 1.15, EW 0.20-0.35, EL 0.30 - 0.40, SL 1 .45 - 1 .50, FL 2.30 - 2.70, WL 2.50 - 2.95, WPL 3.15 - 3.80, PL 0.65 - 0.70, PW 0.90 - 0.65, PH 1.10 - 1.25, CI 86.48 - 88.57, OI 19.35 - 25.00, Mandl 51.42 - 62.16, SI 93.54 - 93.75, Peti 92.85 - 138.46. Total length 8.65 - 11.10 mm; head subquadrate; anterior margin of clypeus with single medial raised area that forms narrow smooth shiny flat strip with slight depression on anterior part covered with fine striae in some specimens, simply small shiny groove without striae in other specimens; head, pronotum, propodeum, petiole and postpetiole roughly sculptured; pronotal humerus rounded anteriorly and straight on lower margin (lateral view); basalar sclerite rounded; petiole rounded dorsoanteriorly with medium rounded apex and vertical posterior face (side view); dorsum of pronotum, propodeum, petiole and postpetiole covered with few moderately short (0.15 - 0.25 mm) erect scattered hairs; hairs on ventral surface of head few and moderately long (0.15 - 0.35 mm); short erect (0.10 mm) hairs on top of head; color mostly black or dark brown to reddish brown; mandibles and head pale brown to dark brown; legs and mandibles often reddish brown; tibia and scape often dark brown, tarsus and funiculus light bro

Queen
(n=15), HL 1.55 - 1.80, HW 1.40 - 1.65, ML 0.80 - 1.10, EW 0.25 - 0.35, EL 0.30 - 0.40, SL 1.25 - 1.45, FL 2.25 - 2.45, WL 2.45 - 2.95, WPL 3.20 -3.75, PL 0.65 - 1.70, PW 0.85- 0.95, PH 1.05 - 1.20, CI 90.32 - 91.67, OI 21.42 - 24.24, Mandl 51.61 - 61.11, SI 87.88 - 89.28, Peti 55.88 - 130.76. Metanotum well separated between propodeum and scutellum; metakatepisternum distinctive from lateropropodeum; propodeal spiracle elongate; petiole rounded anteriorly, vertical posteriorly (side view); postpetiole and remainder of gaster larger than mesosoma. Erect hairs (0.20 - 0.37 mm) on dorsum of pronotum, scutum, scutellum, propodeum, petiole and postpetiole; top of head covered with few shorter erect hairs (0.15 mm). Short erect and suberect hairs (0.10 - 0.20) scattered on scape and legs.

Male
(n=12), HL 1.20 - 1.25, HW 0.95, ML 0.30 - 0.45, EW 0.40, EL 0.60 - 0.70, SL 0.25, FL 3.90 - 4.05, WL 2.40 - 2.65, WPL 3.30 - 3.45, PL 0.60, PW 0.65 - 0.75, PH 0.90, CI 76.00 - 79.16, 01 63.15 - 76.68, Mandl 25.00 - 36.00, SI 26.31, Peti 108.33 - 125.00. Total length 6.45 - 7.45 mm; head excluding mandibles nearly round; eyes large, cover most of sides of head; scape shorter and thicker than second funicular segment, twice length the pedicel; pronotum rounded anteriorly, square posterior-laterally; notauli present on dorsum of scutum; metanotum without carina; postpetiole rounded (side view); pronotum, scutum, scutellum, propodeum, petiole and postpetiole roughly sculptured; moderately long hairs (0.20 - 0.25 mm) scattered on dorsum of scutellum, metanotum, propodeum, petiole and postpetiole; pronotum, postpetiole, clypeus, scape and legs light brown, head, scutum, scutellum, propodeum and petiole dark brown.

Type Material
Ponera (Bothroponera) soror. Cameroun: South Province, Lolodorf, 3°14'0" N; 10°44'0" E, xi-xii, vi-vii, ix-xi, vii-1895, L. L. Conradt, Ponera (Bothroponera) soror Emery 1899, (1 lectotype worker, 8 paralectotype workers and 2 paralectotype females [here designated] ).