Bothroponera kruegeri

Bothroponera kruegeri
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Ponerinae
Tribe:	Ponerini
Genus:	Bothroponera
Species group:	sulcata
Species:	B. kruegeri
Binomial name
Bothroponera kruegeri (Forel, 1910) Specimen labels
Synonyms
Pachycondyla kruegeri rhodesiana Forel, 1913 Pachycondyla asina Santschi, 1912

Joma and Mackay (2017) - Bothroponera kruegeri has been collected from different habitats in Africa, principally farmlands and tropical forests. Colonies of this ant were studied extensively to investigate the gamergate number (workers with the ability to reproduce), control over reproduction (Wildman and Crewe, 1988) and qualitative relations of egg size, egg production and colony size (Villet 1990). Bothroponera kruegeri has a specific form of regulation of gamergate numbers in their colonies. There is a single gamergate present in B. kruegeri colonies, which had 3 to 6 mature oocytes (Peeters and Crewe, 1985; Peeters and Crewe, 1986; Wildman and Crewe, 1988; and Peeters and Higashi, 1989). Moreover, B. kruegeri gamergates are able to produce between 0.5-3 eggs per day (Wildman and Crewe, 1988). Bothroponera kruegeri (B. rhodesiana) builds several entrances for their nest and the adjacent area contains loose earth (Wheeler, 1922b; Arnold, 1915).

At a Glance

• Gamergate

Identification

Joma and Mackay (2017) - A member of the Bothroponera sulcata species complex. Worker The main distinguishing character of Bothroponera kruegeri is that it is the largest ant among the Bothroponera sulcata species complex (total length 11.75 - 12.55 mm). The mandibles are narrowed and covered with fine striae and have about 8-9 teeth. The anterior medial margin the clypeus is convex, with a medial raised area that rarely forms a short elongate groove anteriorly (often absent). The frontal lobes are divided by a shallow frontal furrow, which is not continued to the irons.

The head, pronotum, mesopleuron, propodeum, petiole and postpetiole are roughly sculptured and moderately shiny. The lower lateral margins of the pronotum are straight and form angular inferior and anteroinferior pronotal processes. The dorsopropodeum broadly curves posteriorly to gradually reach the articulation point with the petiole between the propodeal lobes.

The entire surface of the body is hairy and black.

The worker of Bothroponera kruegeri is similar to those of the B. sulcata complex members except for some unique characters such as the large total length (11.75 - 12.55 mm total length for the worker and 10.25 mm for the male), the number of mandibular teeth (8-9 teeth, which is the largest number among the B. sulcata complex species), the anterior raised area of the clypeus and the postero-dorsopropodeal shape. The anterior medial raised area of the clypeus is convex in all of the B. sulcata complex members, but this area forms a smooth and shiny raised medial area without a clypeal carina in Bothroponera crassa, a longitudinal shiny groove not well developed or even absent in Bothroponera ilgii, Bothroponera picardi, Bothroponera silvestrii and Bothroponera ryderae, a narrowed longitudinal smooth strip usually without a groove in B. silvestrii and B. pilosuperficia. In Bothroponera soror, the clypeus has a single medial raised area that forms a shiny, completely or partially striated area or a smooth shiny narrowed groove. Conversely the anterior raised area of the clypeus of B. kruegeri forms a raised sculptured area on the upper part and tiny shiny area that seems to have a small depression close to the lower clypeal margin. The dorsopropodeum forms a broadly curved outline the connects gradually with the posteropropodeum and reaches the insertion point of the petiole. The dorsopropodea of B. silvestrii, B. crassa, B. ilgii, and Bothroponera notaula are more strongly curved than that of B. kruegeri to form an angle with the posteropropodeum. The dorsopropodeum forms a strong angle with the posteropropodeum, which strongly slopes posteriorly in B. soror, B. silvestrii, B. picardi, Bothroponera ancilla, B. ryderae and B. pilosuperficia.

Male - The head is nearly circular, excluding the mouth parts and the mandibles. The ocelli are relatively large. The scape is shorter and thicker than the second funicular segment, twice the length of the pedicel. The notauli are weakly developed on the dorsum of the scutum. The scutum is distinguished by three brown areas, two are around each of the parapsidal sutures and one is a triangular spot between the notauli. The medial area, between the brown spots is pale brown or yellow in color. The scutellum is triangular and elevated in dorsal view. The metanepisternum is well distinguished while the metakatepisternum is triangular and poorly developed. The dorsopropodeum gradual slopes posteriorly to reach the insertion of the petiole. The petiolar node is small, its width is less than the width of the dorsopropodeum and its height is less than that of the postpetiole height and has a pointed apex. The postpetiole is rounded anteriorly. The pronotum, scutum, scutellum, propodeum, petiole and postpetiole are roughly sculptured.

The entire body is covered with fine short dense hairs and scattered long hairs on the dorsum of the scutellum, metanotum, propodeum, petiole and postpetiole.

The surface color is mostly light brown and yellowish.

The male of Bothroponera kruegeri can be compared with other known males of the B. sulcata species complex, including those of B. crassa, B. ilgii, B. silvestrii, B. notaula, B. ryderae and B. soror. The total length of B. kruegeri is 10.25 mm which is the largest body length among other male castes, including B. soror (6.45 - 7.45 mm), B. crassa (5.90 - 7.50 mm), B. notaula (5.60 - 7.90 mm), B. ryderae (6.45 mm) and B. silvestrii (4.70 - 5.10 mm). The total length of B. ilgii is unavailable as the gaster is missing in the only available male type specimen. The notauli are absent or weakly defined in B. kruegeri similar to those in B. crassa and B. ilgii while they are present in B. soror, B. silvestrii, B. notaula and B. ryderae. The ocelli are large in B. kruegeri, B. notaula and B. crassa, but they are small in B. soror and the type specimen of B. ilgii, similar to that in B. silvestrii and B. ryderae. The entire surface of B. kruegeri is rough, similar to that of B. crassa and B. ilgii, but in B. soror the mesosoma and petiole are roughly sculptured with punctures. The dorsopropodeum gradually slopes posteriorly in B. kruegeri as in B. crassa, B. ilgii, B. silvestrii and B. notaula, but in B. soror it is strongly curved posteriorly similar to that in B. picardi, B. silvestrii, B. ancilla, B. ryderae and B. pilosuperficia.

Keys including this Species

• Key to Bothroponera sulcata species complex
• Key to Ethiopian Bothroponera

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -7.89932° to -28.125°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Afrotropical Region: Kenya, Mozambique, South Africa (type locality), United Republic of Tanzania, Zimbabwe, Zimbabwe.

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Castes

Worker

.	Owned by Museum of Comparative Zoology.

Male

.	Owned by Museum of Comparative Zoology.

.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

• kruegeri. Pachycondyla (Bothroponera) kruegeri Forel, 1910a: 28 (w.) SOUTH AFRICA.
  • Type-material: lectotype worker (by designation of Joma & Mackay, 2017:27), 1 paralectotype worker.
  • [Notes (i): original description does not cite number of syntypes; (ii) Baroni Urbani, 1973b: 134, cites 1w syntype NHMB.]
  • Type-locality: lectotype South Africa: Transvaal, Valdezia (P. Berthoud); paralectotype with same data.
  • Type-depositories: MHNG (lectotype); MHNG, NHMB (paralectotypes).
  • Combination in Pachycondyla: Brown, in Bolton, 1995b: 306;
  • combination in Bothroponera: Wheeler, W.M. 1922a: 22; Schmidt, C.A. & Shattuck, 2014: 77.
  • Status as species: Emery, 1911d: 77; Forel, 1913a: 109; Santschi, 1914e: 4; Arnold, 1915: 56 (redescription); Wheeler, W.M. 1922a: 72 (in key), 770; Arnold, 1926: 202; Arnold, 1952a: 462 (in key); Prins, 1963: 98; Bolton, 1995b: 306; Joma & Mackay, 2017: 23 (redescription).
  • Senior synonym of asina: Joma & Mackay, 2017: 23.
  • Senior synonym of rhodesiana: Joma & Mackay, 2017: 23.
  • Distribution: Kenya, South Africa, Zimbabwe.
• asina. Pachycondyla (Bothroponera) asina Santschi, 1912b: 153 (w.) KENYA.
  • Type-material: holotype worker.
  • Type-locality: Kenya (“Afrique orientale anglaise”): (no further data) (received from Demarchi).
  • Type-depository: NHMB.
  • Combination in Pachycondyla: Brown, in Bolton, 1995b: 303;
  • combination in Bothroponera: Wheeler, W.M. 1922a: 770; Schmidt, C.A. & Shattuck, 2014: 77.
  • Subspecies of kruegeri: Santschi, 1914e: 4; Wheeler, W.M. 1922a: 770; Arnold, 1926: 202; Bolton, 1995b: 303; Hita Garcia, et al. 2013: 221.
  • Junior synonym of kruegeri: Joma & Mackay, 2017: 23.
• rhodesiana. Pachycondyla (Bothroponera) kruegeri var. rhodesiana Forel, 1913a: 109 (w.) ZIMBABWE.
  • Type-material: lectotype worker (by designation of Joma & Mackay, 2017: 27), 2 paralectotype workers.
  • [Note:Baroni Urbani, 1973b: 134, cites 1w syntype NHMB.]
  • Type-locality: lectotype Zimbabwe (“Rhodesia”): Bulawayo (G. Arnold); paralectotypes with same data.
  • Type-depository: NHMB (perhaps also MHNG).
  • Arnold, 1915: 57 (m.).
  • Combination in Pachycondyla: Brown, in Bolton, 1995b: 308;
  • combination in Bothroponera: Wheeler, W.M. 1922a: 770; Schmidt, C.A. & Shattuck, 2014: 77.
  • Subspecies of kruegeri: Arnold, 1915: 57; Wheeler, W.M. 1922a: 770; Bolton, 1995b: 308.
  • Junior synonym of kruegeri: Joma & Mackay, 2017: 23.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Joma and Mackay (2017) - (n=9), B. kruegeri measurements: HL 2.30 - 2.40, HW 2.00 - 2.10, ML 1.40, EW 0.40, EL 0.60, SL 2.00 - 2.20, FL 3.00 - 3.10, WL 3.70 - 3.80, WPL 4.60 - 4.70, PL 1.00, PW 1.10, PH 1.50 - 1.60, CI 86.95 - 87.50, OI 28.57 - 30.00, Mandl 58.33 - 60.86, SI 100.00 - 104.76, Peti 110.00. B. asina measurements: HL 2.20, HW 2.00, ML 1.30, EW 0.40, EL 0.50, SL 1.90, FL 3.00, WL 3.70, WPL 4.50, PL 0.90, PW 1.20, PH 1.50, CI 90.90, OI 25.00, Mandl 59.09, SI 95.00, Peti 133.33. B. rhodesiana measurements: HL 2.50 - 2.70, HW 1 .95 - 2.20, ML 1 .50 - 1 .55, EW 0.45, EL 0.65 - 0.70, SL 2.10 - 2.25, FL 3.25 - 3.40, WL 3.60 - 4.20, WPL 4.40 -5.00, PL 1.00- 1.05, PW 1.15- 1.35, PH 1.65 - 1.95, CI 78.00 - 81.48, OI 33.33 - 31.81, Mandl 57.40 - 60.00, SI 102.27 - 107.69, Peti 115.00 - 128.57. Compound eyes relatively large; malar space length 0.45 - 0.50 mm, area from upper edge of eye to upper margin of posterior lobe 0.85- 0.95 mm; pronotal humerus rounded anteriorly with straight ventral margin (side view) that forms sharp anteroinferior and inferior pronotal processes; dorsopropodeum slightly curved, posteropropodeum slightly concave, with slight medial depression, seen from dorsal or from posterior view; entire surface of body covered with fine hairs; dorsum of pronotum, propodeum, petiole and postpetiole covered with few moderately short (0.20 mm) erect scattered hairs; head covered with few short (0.10 - 0.20 mm) erect hairs; short (0.10-0.15 mm) erect hairs scattered on legs and scape; hairs on ventral surface of head moderately long (0.20 - 0.35 mm); color of entire body black; tibia, clypeus and scape brownish black, tarsus, funiculus and mandibles reddish brown.

Male

Joma and Mackay (2017) - (n=l), HL 1.45, HW 1.05, ML 0.35, EW 0.60, EL 0.95, SL 0.30, FL 5.90, WL 3.45, WPL 4.35, PL 0.75, PW 0.70, PH 1.15, CI 72.41, OI 90.47, Mandl 24.13, SI 28.57, Peti 93.33. Total length 10.25 mm; eyes large, cover most of sides of head; scape shorter (0.35 mm), twice as long as pedicel length (0.15 mm) and thicker than second funicular segment (length 0.55 mm); pronotum quadrate laterally and rounded anteriorly; scutellum triangular, elevated in dorsal view; Longer hairs (0.20 - 0.35 mm) scattered on dorsum of scutellum, metanotum, propodeum and petiole; hairs on dorsum of postpetiole range in length from 0.25 - 0.30 mm; long hairs appear on suture between pronotum and scutum.

Type Material

Joma and Mackay (2017) - South Africa: Valdezia, Transvall, 23°6’0’’ S; 30°11’0’’ E, P. Bethould collector, Pachycondyla (Bothroponera) kruegeri Forel, 1910a, new species (2w, lectotype upper specimen, paralectotype lower specimen [here designated and type locality restricted] Naturhistorisches Museum, Basel). 6 workers: Kenya: Afrique orientale anglaise, Nirobi, Nairobi Area, 1°17’0’’ S; 36°49’0’’ E, Pachycondyla (Bothroponera) asina Santschi (1w, holotype, NHMB). Zimbabwe: Bulawayo, 2 Bulawayo Fan., 1912. 20°9’0’’ S; 28°35’0’’ E, Bothroponera kruegeri var. rhodesiana Forel, G Arnold, (3w, lectotype upper specimen, paralectotype lower specimens [here designated] NHMB).

References

• Arnold, G. 1915. A monograph of the Formicidae of South Africa. Part I. Ponerinae, Dorylinae. Ann. S. Afr. Mus. 14: 1-159 (page 56, see also)
• Brown, W. L., Jr. 1995a. [Untitled. Taxonomic changes in Pachycondyla attributed to Brown.] Pp. 302-311 in: Bolton, B. A new general catalogue of the ants of the world. Cambridge, Mass.: Harvard University Press, 504 pp. (page 306, Combination in Pachycondyla)
• Esteves, F.A., Fisher, B.L. 2021. Corrieopone nouragues gen. nov., sp. nov., a new Ponerinae from French Guiana (Hymenoptera, Formicidae). ZooKeys 1074, 83–173 (doi:10.3897/zookeys.1074.75551).
• Forel, A. 1910a. Glanures myrmécologiques. Ann. Soc. Entomol. Belg. 54: 6-32 (page 28, worker described)
• Joma, A.M.A. & Mackay, W.P. 2017. Revision of the African ants of the Bothroponera sulcata species complex (Hymenoptera: Formicidae: Ponerinae). Transactions of the American Entomological Society. 143:7-71.
• Peeters, C.P. & Crewe, R.M. 1986. Queenright and queenless breeding systems within the genus Pachycondyla (Hymenoptera: Formicidae). Journal of the Entomological Society of South Africa, 49: 251-255. (=Bothroponera kruegeri and Euponera wroughtonii compared)
• Schmidt, C.A. & Shattuck, S.O. 2014. The higher classification of the ant subfamily Ponerinae (Hymenoptera: Formicidae), with a review of ponerine ecology and behavior. Zootaxa 3817, 1–242 (doi:10.11646/zootaxa.3817.1.1).
• Wheeler, W. M. 1922a. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. I. On the distribution of the ants of the Ethiopian and Malagasy regions. Bull. Am. Mus. Nat. Hist. 45: 13-37 (page 22, Combination in Bothroponera)
• WILDMAN, M.H. & CREWE, R. 1988. Gamergate number and control over reproduction in Pachycondyla krugeri (Hymenoptera, Formicidae). Insectes Sociaux 35: 217–225.

References based on Global Ant Biodiversity Informatics

• Arnold G. 1915. A monograph of the Formicidae of South Africa. Part I. Ponerinae, Dorylinae. Annals of the South African Museum 14: 1-159.
• Emery C. 1911. Hymenoptera. Fam. Formicidae. Subfam. Ponerinae. Genera Insectorum 118: 1-125.
• Forel A. 1910. Glanures myrmécologiques. Ann. Soc. Entomol. Belg. 54: 6-32.
• IZIKO South Africa Museum Collection
• Joma A. M. A., and W. P. MacKay. 2017. Revision of the African ants of the Bothroponera sulcata species complex (Hymenoptera: Formicidae: Ponerinae). Transactions of the American Entomological Society, 143(1): 7-71.
• Prins A. J. 1963. A list of the ants collected in the Kruger National Park with notes on their distribution. Koedoe 6: 91-108.
• Prins A. J. 1964. Revised list of the ants collected in the Kruger National Park. Koedoe 7: 77-93.
• Prins A. J., and J. J. Cillie. 1968. The ants collected in the Hluhluwe and Umfolozi game reserves. The Lammergeyer 8: 40-47.
• Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004