Bothroponera laevissima (Arnold)

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 : 553-554

Bothroponera laevissima (Arnold)

Figures 14, 15 and Plate 6 ; Map 7

Pachycondyla (Bothroponera) laevissima Arnold, 1915: 58 (w) South Africa, Cape Province, Saldanha Bay; Bothroponera laevissima: Wheeler, W.M. 1922: 73 ; Joma and Mackay: 2013: 3; Schmidt and Shattuck, 2014: 76; Pachycondyla laevissima: Brown , in Bolton, 1995: 306

Diagnosis: The workers of Bothroponera laevissima are large (total length 12 - 13 mm) shiny black ants. The mandibles are shorter than the head length and covered with fine striae. The anterior medial raised area of the clypeus is convex, but lacks a longitudinal carina; the anterior border is “u” shaped. The lower margin of the clypeus has a short grooved beak on the lower margin of the posteroclypeus. The metapleural area is compressed in some specimens.

The head is smooth and shiny with few punctulae scattered on the surface.The pronotum, mesonotum, mesopleuron, propodeum, petiole and postpetiole are smooth and shiny with a few scattered punctulae. The petiole is more sculptured than the other body parts. The second gastral tergite is smooth and glossy.

Worker Description: (n=9), HL 2.90 - 3.10, HW 2.50 - 2.65, ML 1.55 - 1.70, EW 0.35, EL 0.35 - 0.40, SL 1.95 - 2.15, FL 2.95 - 3.10, WL 3.65 - 3.95, WPL 4.40 - 4.85, PL 0.95 - 1.10, PW 1.15 - 1.30, PH 1.35 - 1.55, CI 85.48 - 86.20, OI 14.00 - 15.09, MandI 53.44 - 54.83, SI 78.00 - 81.13, PetI 118.18 - 121.05. Head suborbiculate; mandibles with 7 teeth; clypeal length 2.15 - 2.35 mm; frontal lobe width 0.90 - 1.05 mm; scape nearly reaches posterior lateral corner of head; compound eyes relatively large; malar area length 0.60 - 0.75 mm, length from upper margin of eye to upper margin of posterior corner of head 1.25 - 1.45 mm; area around basalar sclerite depressed; basalar sclerite oval; propodeum rounded; propodeal spiracle elongated, diagonal on lateropropodeum; sternopostpetiolar process well developed; edges and anterior part of frontal lobes shiny; entire body covered with scattered or moderately abundant short erect silver hairs (0.07 - 0.10 mm), hairs on dorsum denser than those on sides, longer than those on head, similar hairs on petiole, postpetiole, range from 0.10 - 0.15 mm; entire body black; legs, antennae and mandibles brownish.

Comparison: The worker of B. laevissima can be recognized as a shiny black ant. The general characters of the worker of B. laevissima are similar to those of the worker of B. aspera , but the lower margin of the anterior medial raised area of the clypeus has a “u” shape in B. laevissima while it has “v” shape in B. aspera . The lower margin of the clypeus forms a grooved beak in B. laevissima , which is not found in B. aspera . Despite that they both have a shiny surface and black color, B. laevissima is characterized by a smooth head with few scattered punctulae, similar to the pronotum, mesonotum, mesopleuron, propodeum, petiole and postpetiole. The petiole is more sculptured than other body surfaces; the second gastral tergite is smooth. Conversely, B. aspera is recognized as rough with dense shallow punctulae on the body surface (head, pronotum, mesonotum, mesopleuron, propodeum, petiole and postpetiole), the tergum of the second-fifth gastral segments are mostly smooth and glossy. Due to the mostly polished sculpture, B. laevissima would not be confused with any other species except B. aspera . Bothroponera laevissima was collected from Saldanha Bay, Western province area of South Africa, where B. aspera also occurs, which further suggests they are separate species.

Material examined

Type material: SOUTH AFRICA: Western Cape Province, Saldanha Bay, 33°1’0’’ S; 17°57’0’’ E, ix-1912, L. P., Rhodesian museum, South Africa museum ex. national museum Bulawayo 1981, Pachycondyla laevissima G. Arnold , SAM-ENT 11518, 11517, Bothroponera laevissima (4w, lectotype marked with red dot and 3 paralectotype worker without dot [here designated], Iziko). leg. F. Peringuey; ix 1912; Pachycondyla laevissima, G. Arnold ; Arnold coll. B. M. 1934-354 (BMNH (E) 1015515) Antweb Casent 0 902471, Bothroponera laevissima (2w, Syntypes, BMNH).

Non-type material: SOUTH AFRICA: Western Cape Province, Saldanha Bay, 33°1’0’’ S; 17°57’0’’ E, Sept. 1912, L. P., Arnold determ., Pachycondyla laevissima G. Arnold , SAM-ENT 0 0 11517, Bothroponera laevissima (3w, Iziko).

Distribution: Known from Saldanha Bay, South Africa. A B. laevissima worker was collected from Jacobsbai, 32°58’0’’ S; 17°53’0’’ E, Cape Province by H. G. Robertson and C. Peeters (The Ants of Africa website, accessed March 2014).

Biology and habitat: The Western Cape Province includes the Cape Floristic Region (CFR), which is considered one of the global biodiversity hotspots that needs priority conservation attention. It is small area, but includes high plant species richness, especially plants considered as endemics to CFR. It also includes several endemic species of birds, amphibians, insects and a few invertebrates ( Giliomee, 2003). Ants play an important role in maintaining this ecosystem and they use different habitat such as under litter, on the ground, in logs, inside dead trees and on tree branches. The nest of B. laevissima from Jacobsbai, Cape Province, South Africa was found in sandy soil (The Ants of Africa web, accessed May 2014). The main vegetation characterizing the Western Province are Fynbos and Succulent Karoo biomes with high floral diversity accompanied by a moderate to high biodiversity of ant species. Although these ecosystems have their own biodiversity and richness of organisms resembling similar global ecosystems, they contain less ant biodiversity and richness than rainforest habitats ( Braschler et al., 2012). Both B. laevissima and B. aspera , with B. cavernosa , B. montivaga and B. granosa were collected from the Western Cape Province. The various vegetation types and biodiversity in the Western Cape Province has apparently led to high speciation in the area which may happen only in this and similar areas in South Africa. The Cape Provinces in South Africa include Eastern Cape, Western Cape, and Northern Cape and includes about half of the B. pumicosa species complex species. For example, B. strigulosa is found in the Northern Cape, B. berthoudi in the Eastern Cape with the previous five species in the Western Cape Province. The Cape Provinces are unique because they also hold the majority of the South Africa area and all types of biomes, including Forest, Nama Karoo, Fynbos, Thicket, Savanna and Succulent Karoo.

Figures

Plate 6: Bothroponera laevissima, lectotype worker.

Map 7. The distribution of B. laevissima.