Bothroponera ancilla

The biogeographical area of the type specimen of B. ancilla has habitat that differs from that of the other species. The type specimen was collected from the Congo, on the western side of the African continent while the additional specimens were collected from Gabon, Kenya, Mozambique and Tanzania on the eastern side of Africa. The specimens were collected from the equatorial rainforest in Kenya and from secondary forests in Mozambique. They were loose individuals from a guesthouse clearing, along a forested edge of stream and from leaf litter and on the ground. The distribution of B. ancilla indicates that this species must be widespread in tropical and subtropical rainforests of Africa. (Joma and Mackay 2017)

Identification
Joma and Mackay (2017) - A member of the Bothroponera sulcata species complex. Workers of Bothroponera ancilla have characters similar to those of other members of the Bothroponera sulcata species complex with some exceptions. The mandibles are smooth, shiny and sparsely punctate, narrowed and have about 7 teeth that do not always alternate in size. The anterior medial area of the clypeus is raised to forms a shiny, smooth longitudinal narrowed strip with slight groove in some specimens or with weak evidence of fine striae in others. The compound eyes are relatively small. The malar space length is 0.20 - 0.25 mm while the area from the upper edge of eye to the upper margin of posterior lobe is 0.65 - 0.90 mm.

The head is roughly sculptured with abundant small punctures that cover the surface. The pronotum, propodeum, petiole and postpetiole are roughly sculptured with a few scattered punctures. The second gastral segment (fourth abdominal segment) is mostly shiny and without punctures. The clypeus, legs and antennae are moderately shiny. The lower margin of the pronotum is straight with a rounded anteroinferior pronotal process, and a pointed inferior pronotal process. The dorsopropodeum forms a strong curved posterior edge with the posteropropodeum. The posteropropodeum is slightly concave and the margins form granulated, carinated sharp edges.

The dorsum of the pronotum, propodeum, petiole and postpetiole are covered with a few moderately short (0.15 - 0.25 mm) erect scattered hairs. The hairs on the 4th to 7th abdominal segments are 0.20 up to 0.30 mm in length. The dorsum of the head and irons are covered with a few short (0.10 - 0.15 mm) golden erect hairs. Hairs are silver on the mesosoma, but appear yellowish on petiole and gaster.

Bothroponera ancilla can be separated from Bothroponera soror by the following characters. The anterior medial raised area of the clypeus forms a smooth shiny flat narrowed longitudinal strip that occasionally has a slight depression (groove) or even striae. The clypeuses of the type specimens of B. soror have a single medial raised area that forms a shiny striated narrowed, slightly grooved strip. The fine striae of the anterior medial raised area of the clypeus are absent in the type specimen of B. ancilla that was collected from Congo while the fine striate of the anterior medial raised area of the clypeus are poorly developed in the other material of B. ancilla that was collected from Gabon, Kenya, Tanzania and Mozambique. The eye size of B. ancilla is identical th that of Bothroponera pilosuperficia, but smaller than that of B. soror. The differences are sufficient to consider B. ancilla to be as separate species.

The malar space length in B. ancilla is 0.20-0.25 mm, in B. pilosuperficia it is 0.17-0.22 mm and in B. soror it is 0.25-0.35 mm while the area from upper edge of eye to the upper margin of posterior lobe in B. ancilla is 0.65-0.90 mm, in B. pilosuperficia it is 0.80-0.90 mm, in B. pilosuperficia it is up to 0.95 mm. This indicates that the B. soror has a larger head than B. pilosuperficia and B. ancilla.

The distribution of the hairs on the surfaces is similar in B. ancilla and B. soror, but these two differ slightly from that in B. pilosuperficia. The dorsum of pronotum, propodeum, petiole and postpetiole in B. ancilla are covered with a few moderately short (0.20-0.25 mm) erect scattered hairs similar to those of B. soror (0.15-0.25 mm) while the head is usually bare in B. ancilla, but the posterior border and frons of the head are covered with a few scattered short (0.10-0.15 mm) erect hairs in B. ancilla. In B. pilosuperficia, the entire surface including the head is covered with abundant and moderately long (0.15-0.30 mm) silver erect hairs.

The general color among these species and even the others in the complex shows a wide range of variability from light brown to dark brown and yellow to reddish brown in other cases.

Distribution
Southern Africa including the Congo, Gabon, Kenya, Mozambique and Tanzania.

Distribution based on Regional Taxon Lists
Afrotropical Region: Congo, Gabon, Kenya, Mozambique, United Republic of Tanzania.

Nomenclature

 *  ancilla. Ponera (Bothroponera) soror var. ancilla Emery, 1899e: 472 (w.) CONGO.
 * Combination in Pachycondyla (Bothroponera): Emery, 1901a: 46.
 * Combination in Bothroponera: Wheeler, W.M. 1922a: 74.
 * Combination in Pachycondyla: Brown, in Bolton, 1995b: 302.
 * Combination in Bothroponera: Schmidt & Shattuck, 2014: 77.
 * Raised to species: Joma & McKay, 2017: 12

Worker
Joma and Mackay (2017) - (n=21), HL 1.45 - 1.70, HW 1.25 - 1.48, ML 0.85 - 1.10, EW 0.18 - 0.22, EL 0.25 - 0.30, SL 1.15-1 .36, FL 1 .95 - 2.45, WL 2.20 - 2.50, WPL 2.75 - 3.25, PL 0.55 - 0.65, PW 0.75 - 0.85, PH 0.95 - 1.15, CI 86.20 - 87.05, OI 20.00 - 20.27, Mandl 58.62 - 64.70, SI 91.89 - 92.00, Peti 130.76 -136.36. Total length 6.75 - 8.90 mm; head subquadrate; mandibles smooth, shiny; head, pronotum, propodeum, petiole and postpetiole roughly sculptured; petiole rounded dorso-anteriorly with medium rounded apex and vertical posterior face (side view); hairs on ventral surface of head few and long (0.25 - 0.35 mm); entire body black or brown, pronotum, propodeum, petiole and postpetiole brownish black (or dark brown). Head and clypeus light brown to reddish, mandibles reddish brown to yellowish brown, legs and antennae brown.

Type Material
Joma and Mackay (2017) - People’s Republic of the Congo: Congo Brazzaville: Kouilou Province, Kuilu, Congo Brazzaville River, [Kouilou] 3°30’ to 4°30’S, 11°45’ to 12°0’E, 4°28’15’’S, 11°41’56’’E, Ponera (bothroponera) soror ras. ancilla Emery 1899, museo Genova coll. C. Emery (dono 1925) (1w, holotype, ).