Bothroponera pilosuperficia

Bothroponera pilosuperficia is known from rainforests in Gabon and Cameroon.

Identification
Joma and Mackay (2017) – Worker Similar to other Bothroponera sulcata species complex species with some exceptions. The mandibles are narrowed and have 7 teeth that alternate in size with space between the two basalmost teeth, wide enough for another tooth, in some specimens, there is a small tooth between the two teeth; the mandibles are smooth and weakly shiny. The clypeus has a single medial raised longitudinal area that forms a shiny, partially striated raised medial strip, but does not form a groove. The compound eyes are relatively small.

The entire surface of the head, mesosoma and gaster is covered with fine hairs (length less than 0.02 mm). The head is covered with relatively short to moderately long (0.05 - 0.20 mm) abundant erect silver hairs of different lengths. The notopropodeum is covered with moderately longer (0.10 up to 0.22 mm) erect silver hairs, more abundant than those on the head. The posterior half of the pronotum is covered with longer (up to 0.26 mm) erect hairs. The propodeum, petiole, postpetiole and the 4th to 7th abdominal segments are covered with abundant, relatively long (0.23 - 0.36 mm) abundant erect silver hairs.

The holotype specimen has a reddish brown head and a dark brown mesosoma, petiole gaster, but other specimens are darker. The mandibles and appendages are light brown medium brown.

The species most similar to B. pilosuperficia in regards to the structure of the dorsopropodeum and posteropropodeum are Bothroponera ancilla, Bothroponera soror, Bothroponera silvestrii, Bothroponera picardi, and Bothroponera ryderae. Those species have a semi-vertical posteropropodeum with a slightly concave surface and granulated curved lateral margins. On the other hand, Bothroponera crassa, Bothroponera ilgii, B. silvestrii, and Bothroponera notaula have a posteropropodeum that slopes gradually posteriorly to reach the insertion point of the petiole with the mesosoma, between the propodeal lobes.

The worker of B. pilosuperficia is characterized by an unusual distribution of hair of various lengths (0.05 to 0.36mm) on the head, pronotum, notopropodeum, mesopleuron, petiole, postpetiole and 4th to 7th abdominal segments. The head of B. soror lacks erect hairs except for a few on the dorsal surface or on the frons as in B. ancilla. The hairs on the dorsum of the pronotum, propodeum, mesopleuron, petiole, postpetiole and 4th to 7th abdominal segments of B. soror and B. ancilla are less abundant than those of B. pilosuperficia. The eyes of B. soror (0.20 – 0.40 length, 0.30-0.50 width) are larger than those of B. pilosuperficia (EW 0.15-0.22, EL 0.25-0.30), but the eyes of B. pilosuperficia are almost identical to those of B, ancilla (0.18-0.22 length, 0.25-0.30 width) and B. ryderae (0.20-0.25 length, 0.25-0.30 width). It is easy to separate B. silvestrii because it has a small total length (5.25 – 6.15 mm) and small eye diameters (0.10-0.20 mm width, 0.15-0.25 mm length). Bothroponera picardi can be separated because the entire surface lacks erect hairs except for a few erect hairs on the pygidium and hypopygidium.

The anterior medial raised area of the clypeus of B. pilosuperfica is narrowed, extends longitudinally and is shiny and raised without a groove. There is a slight groove or depression on the raised anterior medial area in both B. ancilla and B. ryderae, but forms a completely or partially striated depression in B. soror. In B. picardi, the anterior medial area of clypeus forms a raised shiny longitudinal strip that is flat or only slightly raised.

Queen The female of B. pilosuperficia is similar to the worker, but with some significant differences in the measurements. The total length of the B. pilosuperficia female is 8.60 - 10.30 mm. The malar space length is 0.15 - 0.20 mm while the area from the upper edge of eye to the upper margin of the posterior lobe is 0.70 - 0.85 mm. The mandibles are smooth, pale, narrowed and with 7 teeth that alternate in size with wide space between the two basalmost teeth. This space is with or without a small tooth.

The lower lateral margin of the pronotum is straight (seen from side view), the anteroinferior pronotal process is rounded while the inferior pronotal process forms a sharp pointed tooth. The dorsopropodeum is narrowed, measuring 0.35 mm long from posterior edge of the posteropropodeum to the notopropodeal suture, 0.90-1.00 mm wide (seen from above). The dorsopropodeum is strongly curved posteriorly to join the posteropropodeum that is semi-vertical (lateral view). The posteropropodeum is slightly concave, structured to fit the anterior face of the petiole, and the margins are curved and granulated. The meso-metapleural suture is well defined. The postpetiole and the 4th to 7th abdominal segments are slightly longer (3.25-3.85 mm) than the mesosoma (2.50-2.80 mm).

The entire surface including the head, mesosoma and gaster is covered with fine hairs that measure up to 0.05 mm in length. The head is covered with moderately short (0.05-0.20 mm) erect hairs. The dorsum of the pronotum, scutum, scutellum, propodeum, petiole, postpetiole and 4th to 7th abdominal segments are covered with moderately long (0.15-0.36mm) erect silver hairs.

The color of the head is reddish brown to dark brown, the notopropodeum, mesopleuron, propodeum and petiole are dark brown to black. The postpetiole and the rest of the gastral segments are reddish brown to dark brown. The legs and scapes are light brown. The mandibles are pale yellowish to light brown.

The female of Bothroponera pilosuperficia can be only compared with the female of B. soror since the female castes of the remaining B. sulcata complex species are unknown. Generally, the females of B. soror and B. pilosuperficia have the same characters, but B. pilosuperficia can be separated based some differences between them. The head of B. pilosuperficia is covered with dense erect hairs that range from 0.05 to 0.20 mm in length, but the head of B. soror is bare, except for a few erect hairs on the posterior margin of the head (less than 0.15 mm). The notopropodeum, petiole, postpetiole and 4th to 7th abdominal segments are covered with moderately long hairs (0.15 - 0.36 mm) in B. pilosuperficia and 0.15 - 0.37 mm in B. soror. The anterior medial area of the clypeus is raised and forms a longitudinal, narrowed, slightly shiny weak groove without striae in B. pilosuperficia, while the anterior medial area of the clypeus of B. soror forms a raised area with a slight depression that is covered partially or completely with fine striae.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Gabon.

Nomenclature

 *  pilosuperficia. Bothroponera pilosuperficia  Joma & Mackay 2017: 32, figs. 21-24, plate 11, ,ap 8 (w.q.) GABON.

Worker
(n=8), HL 1.45 - 1.65, HW 1.30 - 1.48, ML 0.95 - 1.05, EW 0.15 - 0.22, EL 0.25 - 0.30, SL 1.20 - 1.40, FL 1 .95 - 2.25, WL 2.20 - 2.50, WPL 2.90 - 3.25, PL 0.60 - 0.68, PW 0.85 - 0.90, PH 0.95 - 1.25, CI 89.65 - 89.69, OI 19.23 - 20.27, Mandl 63.63 - 65.51, SI 92.30 - 94.59, Peti 132.35 - 141.66. Total length 7.50 - 9.00 mm; head subquadrate; clypeal surface convex, anterior medial margin forms narrowed smooth, shiny, slightly depressed strip; malar space length 0.17 - 0.22 mm, area from upper edge of eye to upper margin of posterior lobe 0.80 - 0.90 mm; head, pronotum, propodeum, petiole and postpetiole roughly sculptured with few scattered punctures, dense, slightly larger on petiole, tiny, dense on head; second gastral segment (fourth abdominal segment) shiny, slightly roughened (less sculptured and lacking punctures); clypeus, legs, antennae moderately shiny; lower margin of pronotal humerus straight with rounded anteroinferior pronotal process, pointed inferior pronotal process; dorsopropodeum slightly curved posteriorly, posteropropodeum strongly sloped to insertion of petiole to form slightly concave posteropropodeum; posteropropodeal margins form lateral granulated edges; petiole rounded dorsoanteriorly with medial rounded apex, posterior and anterior faces vertical.

Queen
(n=2), HL 1.50 - 1.75, HW 1.35 - 1.55, ML 0.95, EW 0.25 - 0.30, EL 0.40, SL 1.15 - 1.30, FL 2.10 - 2.30, WL 2.60 - 2.90, WPL 3.35 - 3.70, PL 0.65 - 0.70, PW 0.85 - 0.98, PH 1.05 - 1.30, CI 88.57 - 90, OI 25.80 - 29.62, Mandl 54.28 - 63.33, SI 83.87 - 85.18, Peti 130.76 - 140.00. Head subquadrate; scape extends slightly past posterior lateral corner of head; clypeus convex, anterior medial margin of clypeus with single medial raised area that forms narrowed smooth, shiny, slightly depressed strip; compound eyes relatively large; head roughly sculptured with weak evidence of punctures; clypeus, legs, antennae moderately shiny; notopropodeum, petiole and postpetiole roughly sculptured with few scattered punctures on dorsum; metanepisternum poorly developed, metakatepisternum fused to form single surface with lateropropodeum; dorsopropodeum strongly curved posteriorly, to form slightly concave posteropropodeum; posteropropodeal lateral margins granulated; petiole rough, covered with slightly larger punctures; postpetiole smooth with weak evidence of few scattered shallow punctures; second gastral segment (fourth abdominal segment) to fifth gastral segment (seventh abdominal segment) smooth, shiny (lacking punctures); petiole rounded dorso-anteriorly with medial rounded apex, posterior and anterior faces vertical; short (from 0.10 to 0.20 mm) erect and suberect hairs scattered on scapes and legs surface of head.

Type Material
Gabon: Makokou, 0°34>0» N; 12°52>0» E, CNRS, vi- vii-1974, W. H. Gotwald, (1 w holotype, ), Same locality: C. N. R. S., 0°11'0" S; 12°12'0" E, vi- 1974, W. Gotwald (2 f paratypes, MCZC), Same locality: 0°34'0" N; 12°52'0" E, x-1972, I. Lieberburg collector, rain forest, #'s 16, 15, 00525692, 00525693 (3w, paratypes, MCZC), same locality, C. N. R. S., 0°11'0" S; 12°12'0" E, vi- 1974 W. H. Gotwald coll., 00525690 (2 w paratypes, ).

Etymology
The new species name "pilosuperficia" is derived from Latin. It is combination of two words, pilosus, which means hairy and superfìcie, which means surface. The specific epithet refers to the erect silver hairs that cover the entire surface including the head of this species.