Strumigenys ludovici

One of the most successful members of the genus and of the Afrotropical dacetines as a whole, ludovici ranges very widely over the whole continent and is also established in Madagascar and Mauritius. (Bolton 1983)

Identification
Bolton (2000) - A member of the Strumigenys lujae-group. The species and its variation is fully described in Bolton (1983) but the characters used here in the key are usually adequate for instant diagnosis. The presence of enlarged denticles basally on the mandible is usually distinctive and is enough on its own to identify ludovici. However, in a few series this may not be immediately obvious and the separation of ludovici from Strumigenys simoni may be problematic. A table of differences between the two is given under simoni. Pronotal sculpture is quite variable in ludovici. In the majority of cases the pronotum is smooth or smooth with superimposed fine oblique to longitudinal costulae. When costulae occur they may be extremely sparse to quite numerous. Some samples have the spaces between the costulae finely punctulate, which is why the species is run out twice in the key.

Bolton (1983) - Closely related to Strumigenys simoni but most ludovici samples are instantly distinguishable by the enlarged basal series of mandibular denticles in the latter. In those few samples where the enlargement of the denticles is not marked the differentiating characters tabulated under simony will separate the two.

Apart from the diagnostic enlarged denticle series ludovici is separated from Strumigenys dotaja by the presence in the latter of flagellate mesonotal hairs and simple gastral hairs; from Strumigenys sulumana and Strumigenys maynei by those species' lack of cephalic flagellate hairs and strongly developed upper scrobe margins. Usually ludovici is distinguished from Strumigenys lujae, Strumigenys serrula and Strumigenys concolor by their blanketing reticulate-punctate pronotal sculpture, which generally is not seen in ludovici, but in the few populations of the latter with a predominantly punctate pronotum the enlarged basal mandibular denticles of ludovici will separate them. Strumigenys miccata shares the character of enlarged basal denticles with ludovici but this minute species is very easily separated by the characters noted in the discussion of the former.

Distribution based on Regional Taxon Lists
Afrotropical Region: Angola, Benin, Cameroun, Comoros, Congo, Democratic Republic of Congo, Gabon, Ghana, Guinea, Ivory Coast, Kenya, Mozambique, Nigeria, South Africa, Sudan, Togo, Uganda, United Republic of Tanzania, Zimbabwe. Malagasy Region: Madagascar, Mauritius, Mayotte.

Nomenclature

 *  ludovici. Strumigenys ludovici Forel, 1904b: 369 (w.) MADAGASCAR. Combination in S. (Trichoscapa): Santschi, 1913b: 258; in Serrastruma: Brown, 1952e: 85; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 123. Senior synonym of alluaudi (and its junior synonym rothkirchi), lotti, nigeriensis: Bolton, 1983: 343. See also: Bolton, 2000: 315.
 * alluaudi. Strumigenys alluaudi Santschi, 1911c: 360 (w.q.) TANZANIA. Combination in S. (Trichoscapa): Santschi, 1913b: 258 (in key); in S. (Cephaloxys): Emery, 1924d: 323; Wheeler, W.M. 1922a: 918; in Serrastruma: Brown, 1952e: 75. Senior synonym of rothkirchi: Brown, 1952e: 75. Junior synonym of ludovici: Bolton, 1983: 343.
 * nigeriensis. Strumigenys (Trichoscapa) alluaudi st. nigeriensis Santschi, 1914d: 376 (w.) NIGERIA. Combination in S. (Cephaloxys): Wheeler, W.M. 1922a: 919. Junior synonym of simoni: Brown, 1952e: 83; of ludovici: Bolton, 1983: 343.
 * rothkirchi. Strumigenys rothkirchi Wasmann, 1918b: 142, pl. 2, figs. 9, 10 (w.) CAMEROUN. Combination in S. (Cephaloxys): Wheeler, W.M. 1922a: 920. Junior synonym of alluaudi: Brown, 1952e: 75.
 * lotti. Strumigenys (Cephaloxys) escherichi subsp. lotti Weber, 1943c: 378, pl. 15, fig. 13 (w.q.) SUDAN. Combination in Serrastruma: Brown, 1952e: 76. Raised to species: Brown, 1952e: 76. Junior synonym of ludovici: Bolton, 1983: 343.

Description
Bolton (1983) - TL 1.9-3.0, HL 0.46-0.66, HW 0.36-0.49, CI 71-80, ML 0.17-0.30, MI 35-50, SL 0.32-0.50, SI 86-115, PW 0.26-0.38, AI 0.55-0.80 (85 measured).

Basal 4-8 denticles on mandibular masticatory margin enlarged, usually very conspicuously coarser broader and longer than the preceding denticle row. In a few samples the enlarged denticles not so obvious and sometimes the enlarged series may be better developed on one mandible than on the other. Upper scrobe margins defined by a narrow flange or rim which is broadest just behind the frontal lobes and peters out posteriorly, frequently the rim not even extending to the apex of the scrobe. Upper scrobe margins each with a fine flagellate hair just behind the level of the eye. Clypeus usually finely reticulate to punctate, only rarely the sculpture reduced. Dorsum of head behind clypeus finely and densely reticulate-punctate. Ground-pilosity of cephalic dorsum of short narrow to moderately broad spatulate hairs which are decumbent and directed anteriorly. A row of longer spatulate hairs present on the false margin of the clypeus which project forwards over the bases of the mandibles. Dorsum of head with a single pair of standing stout hairs which are narrowly clavate apically, situated behind the highest point of the vertex. Pronotum narrowly marginate anteriorly, not marginate laterally. Mesonotum in profile sloping posteriorly to the impressed metanotal groove, the propodeal dorsum shallowly convex and sloping posteriorly to the propodeal teeth; these latter variable in size, usually triangular but sometimes reduced to small rounded lobes. Infradental lamella usually narrow and inconspicuous, only rarely moderately broad but sometimes vestigial. Sides of pronotum usually smooth but sometimes with sculpture, especially on the upper portions. Mesopleuron, metapleuron or both punctate, sides of propodeum punctate. Frequently the central area of the mesopleuron with sculpture reduced or absent, more rarely with the central area of the metapleuron smooth. Sculpture of pronotal dorsum very variable, ranging from almost smooth to moderately strongly sculptured. At one end of the range the pronotum is smooth except for a median longitudinal carina, at the other a number of oblique to longitudinal fine striae or costulae are present and the spaces between them may be finely punctulate. All grades between these extremes have been noted, including a few sample where the pronotum is predominantly punctate. Frequently the striate component is reduced leaving weak punctures as the predominant component, but in this case they are by no means as strongly developed nor as conspicuous as the punctures on the mesonotum. Dorsal surface of mesonotum and propodeum reticulate-punctate. Pronotum with humeral flagellate hairs. Mesonotum with a pair of stout curved standing hairs which are clavate apically. Ground-pilosity of dorsal alitrunk of short curved hairs which are sparse and subdecumbent to decumbent. With the pedicel segments in profile the spongiform appendages reduced. Petiole with a narrow ventral strip and small lateral lobe. Postpetiole with a moderately developed ventral lobe which is larger than the lateral spongiform appendage but smaller, and usually obviously smaller, than the exposed area of the postpetiolar disc. In dorsal view the petiole node reticulate to reticulate-punctate, with a narrow posterior spongiform strip. Postpetiole usually reticulate to reticulate-punctate, rarely the sculpture reduced and superficial, bordered posteriorly by a lamellate spongiform strip which abuts a similar narrow strip on the anterior margin of the first gastral tergite. Basigastral costulae present, usually short. Petiole, postpetiole and gaster dorsally with stout standing hairs which are clavate apically. Colour yellow to mid-brown.

Type Material
Bolton (1983) - Syntype workers, MADAGASCAR: 'Madagascar meridional', 1899 (M. Sikora) [examined].

References based on Global Ant Biodiversity Informatics

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 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * Brown W. L., Jr. 1952. Revision of the ant genus Serrastruma. Bulletin of the Museum of Comparative Zoology 107: 67-86.
 * CSIRO Collection
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 * Weber N. A. 1943. The ants of the Imatong Mountains, Anglo-Egyptian Sudan. Bulletin of the Museum of Comparative Zoology 93: 263-389.
 * Weber N. A. 1952. Biological notes on Dacetini (Hymenoptera, Formicidae). American Museum Novitates 1554: 1-7.
 * Yeo K., T. Delsinne, S. Komate, L. L. Alonso, D. Aidara, and C. Peeters. 2016. Diversity and distribution of ant assemblages above and below ground in a West African forest–savannah mosaic (Lamto, Cote d’Ivoire). Insectes Sociaux DOI 10.1007/s00040-016-0527-6