Bothroponera granosa (Roger)

Ama JOma & Wp MacKay, 2015, Revision of the African Ants of the Bothroponera pumicosa Species Complex (Hymenoptera: Formicidae: Ponerinae), Sociobiology 62 (4), pp. 538-563 : 551-552

Bothroponera granosa (Roger)

Figures 12, 13 and Plate 5 ; Map 6

Ponera granosa Roger, 1860: 290 (w) SOUTH AFRICA, Cape of Good Hope; Bothroponera granosa: Mayr, 1862: 717 ; Dalla Torre, 1893:36; Wheeler, W. M. 1922: 770; Joma and Mackay: 2013: 3; Schmidt and Shattuck, 2014: 76; Pachycondyla (Bothroponera) granosa: Emery, 1901: 45 ; Arnold, 1915: 61(w); Pachycondyla granosa: Arnold, 1926: 201 (m); Brown, in Bolton, 1995: 305; Bolton, 2013.

Diagnosis: The head of the worker is large and subquadrate. The mandibles are covered with hairs and partially by fine weakly defined striae and scattered coarse punctures. The anterior medial margin of the clypeus is “v” shaped with a raised sharp medial longitudinal carina. The scape reaches the posterior lateral corner of the head. The lower margin of the pronotum is straight with a strongly rounded angle at the anteroinferior pronotal process (lateral view), rounded inferior pronotal process and sometimes forming a sharp angle that is pointed posteroventrally. The petiole (dorsal view) is rounded and slightly narrowed anteriorly while it has a slight concavity on the upper medial margin between the two posterior angles of the petiolar apex. The posterior edge of the petiole is vertical (side or top view) and slightly concave (dorsal view). The sternopetiolar process is developed with a single tooth pointed ventrally.

Worker Description: (n= 20), HL 2.90 - 3.10, HW 2.40 - 2.75, ML 1.40 - 1.75, EW 0.30 - 0.40, EL 0.40 - 0.50, SL 1.90 - 2.35, FL 2.90 - 3.50, WL 3.90 - 4.45, WPL 4.80 - 5.40, PL 1.20 - 1.30, PW 1.40 - 1.60, PH 1.50 - 1.80, CI 83 - 89, OI 17 - 18.18, MandI 48.27 - 56.45, SI 79.16 - 85.45, PetI 117 – 123. Total length 13.75 - 14.50 mm; mandibles with 7 teeth; clypeal length 1.70 - 2.35 mm; malar space length from lower edge of eye to base of mandible 0.40 - 0.65 mm; from upper edge of eye to edge of posterior lobe 1.35 - 1.70 mm; frontal lobe width 0.90 - 1.15 mm; metapleuron rough and weakly punctate; head covered with small dense punctures; sides of head covered with fine striae; dorsum of pronotum, mesonotum, mesopleuron, lateropropodeum and propodeum moderately punctate, moderately shiny; metapleuron rough, weakly punctate; petiole covered with deeper sparse punctures and foveolae than postpetiole; postpetiole covered with shallow sparse punctures, foveolate, with weakly defined fine striae; dorsum of second gastral segment covered with shallow foveolae and striae; remaining gastral segments shiny; lower margin of pronotum straight with strong angle at anteroinferior pronotal process, rounded inferior pronotal process; antennae, legs, lower edge of frontal lobes, mandibles shiny; entire surface of B. granosa worker covered with fine short (up to 0.15 mm) silver hairs, denser on second - seventh gastral segments (up to 0.20 mm); entire surface covered with scattered erect golden hairs, including mandibles, scapes; head, pronotum, mesonotum; propodeum covered with short erect golden hairs (0.10 - 0.15 mm); dorsum of petiole covered with short erect golden hairs (0.15 mm); postpetiole, entire gaster covered with longer erect golden hairs (0.15 - 0.20 mm); hairs on sternum of postpetiole, hairs on other gastral segments reach about 0.30 mm.

Head, pronotum, mesonotum, mesopleuron, propodeum, petiole, postpetiole, entire gaster black; legs, antennae, clypeus, mandibles brownish black.

Comparison: The worker of B. granosa can be recognized by the anterior medial raised area of the clypeus (“v” shaped anterior border) that forms a sharp longitudinal carina, which differs from most of the other B. pumicosa species complex members (except B. cariosa and B. strigulosa ). The anterior medial area of the clypeus is also “v” shaped in B. cavernosa , B. montivaga , B. aspera and B. umgodikulula , but without a carina in B. aspera and B. umgodikulula while it is partially carinate in B. cavernosa and B. montivaga . The other species, including B. cariosa , B. strigulosa , B. pumicosa , B. laevissima and B. berthoudi have an anterior medial raised area of the clypeus with a “u” shaped anterior border, however B. cariosa and B. strigulosa have a sharp carinae similar to B.

granosa . The surface of B. granosa is more likely to be rough with moderately scattered punctures than that of the other B. pumicosa species complex taxa, which are always coarsely foveolate except for B. aspera and B. laevissima , which are shiny black with punctate sculpture. The petiolar shape of B. granosa is unique among the B. pumicosa species complex individuals even if the petiolar indices seem not to be separable. The petiole is rounded and slightly narrowed anteriorly (dorsal view) in all species of the B. pumicosa species complex including B. granosa , but the posterior face is deeply depressed from the upper edge to form two rounded apices found only in B. granosa (best seen from above). The petiolar indices vary among the B. pumicosa species complex members in that the smallest PetI recorded were for B. aspera (104.54 - 118.18), and B. berthoudi (105.55), whereas the largest PetI registered was for B. montivaga (130.00). The other species have intermediate PetI, B. umgodikulula (115 - 126), B. granosa (117 - 123), B. strigulosa (117.39), B. laevissima (118.18 - 121.05), B. pumicosa (120.00 - 125.00), B. cariosa (104 - 116), and B. cavernosa (126.08).

Material examined

Type material: The types were not found, therefore, we used specimens determined by Forel and Bolton to define this species. SOUTH AFRICA: KwaZulu-Natal Province, Natal, Broughton, (farm) 29°26’0’’ S; 30°27’0’’ E, Wm. M. Wheeler collection, Pachycondyla (Bothroponera) granosa Roger (1 worker, AMNH, one worker specimen from MfN determined by Forel in 1922. SOUTH AFRICA: George [cgcorge kocysica Browns], Pachycondyla (Bothroponera) granosa Roger, Forel det. 1922, Zool. Mus. Berlin (1w MfN and two specimens from LACM that were determined by Bolton in 1977). Eastern Cape Province, Highland Rd., W. Grahamstown grassy grove, 33°18’0’’ S; 26°32’0’’ E, 22- x-1966, F. Jacot-Guillarmod, collection of W. S. Creighton purchased by LACM 1974 (2 workers # 315919 LACM). One specimen (1 worker # 315920) from the Los Angeles County Museum determined by Forel with no further information. This specimen was in collection of W. S. Creighton, but was purchased by the Los Angeles County Museum in 1974.

Non-type material: SOUTH AFRICA: Eastern Cape Province, Highlands Rd. W., Grahamstown grassy grove, 33°18’0’’ S; 26°32’0’’ E, F. Jacot Guillarmod (3w MCZC, 1w CWEM), Coldsprings, Grahamstown, under stone, 33°18’0’’ S; 26°32’0’’ E, 9-viii-1964, C. Jacot-Guillarmod (1w MCZC), Near Highlands farm SW of Grahamstown C. P., 33°18’0’’ S; 26°32’0’’ E, 22-x-1966, L. H. Weatherill, ANIC Ants Vial 14.164, Ent. 315917, 315918 (4w LACM), 27 km NW of Cathcart, 32°18’0’’ S; 27°8’0’’ E, N. G. Robertson, 16-ix- 1985, C46, h. rock (2w BMNH); KwaZulu-Natal Province, Estcourt Natal, 29°0’0’’ S; 29°53’0’’ E (R.C.W.) 1914, G. Arnold, Arnold coll. B. M. 1934-354, Pachycondyla pumicosa Roger det. B. Bolton 1977 (1w # 315925 LACM). Natal, Drakensberg, 29°0’0’’ S; 29°0’0’’ E, 2200m, 1983, C. Peeters, Giant’s Castle DRA (P) io (3w, BMNH).

Distribution: Most of the specimens of Bothroponera granosa were collected from South Africa, including the Eastern Cape and KwaZulu-Natal Provinces. They were also collected from the Cape of Good Hope ( Roger, 1860), Natal area ( Forel, 1901) and from Cape Knysna and Cape Majuba Nek areas ( Arnold, 1926). Some specimens were collected from Victoria Falls, Zimbabwe ( Arnold, 1926).

Biology and habitat: Bothroponera granosa inhabits the grassy grove areas of West Grahamstown in South Africa, under stones. It can also be found in rocky habitats such as the area north west of Cathcart City in South Africa (label information). The three specimens from Natal, Drakensberg and that from KwaZulu-Natal Province, Estcourt Natal, South Africa were misidentified as B. pumicosa .

Arnold (1926) reported that B. granosa was also taken at Victoria Falls located on the border between Zimbabwe and Zambia, which is far from the South Africa collection sites. The habitat at Victoria Falls is similar to that at the town of Knysna which has the Knysnarivier Stream (River) and the areas are covered with deciduous forests. The stream is connected with the Indian Ocean at the extreme southern shores of South Africa. The material examined was collected from a grassy grove and farmland habitats (information from labels and Google Earth Maps). One specimen was collected from Cape Province, South Africa by F. Jacot-Guillarmod, misidentified in the MCZC as B. cariosa .

The Western Province, KwaZulu-Natal Province and Eastern Province include several other species that belong to the B. pumicosa species complex: B. montivaga , B. aspera and B. laevissima found in the Western Cape Province, B. umgodikulula , B. cariosa , B. granosa , B. cavernosa , B. berthoudi and B. pumicosa found in Eastern Cape Province. Bothroponera granosa was also collected from Knysna, Western Cape Province and Majuba Nek, Eastern Cape Province (2 workers and one male) as material examined ( Arnold, 1926).

Figures

Plate 5: Bothroponera granosa, worker. (From www. antweb. org. Accessed 23 February 2015).

Map 6. The distribution of B. granosa.