Aenictus eugenii

Santschi (1933) observed these ants tending Pseudococcus lilacinus, one of just a few rare records of an army ant associating with honeydew producing insects.

Identification
Identification is straightforward due to the clypeal shape reduced to two teeth between the antennal sockets, its linear mandibles not closing against it and its long overall pilosity. Aenictus mvuvii shares the mandibular configuration but A. eugenii is larger, even in the minima workers (0.59<HW<0.89 vs. A. mvuvii 0.44<HW<0.59, 1.02<WL<1.40 vs. A. mvuvii 0.72<WL<0.91) with relatively longer scapes (69<SIL<83 vs. A. mvuvii 52<SIL<63) and presents long, unequal semierect to erect setae, while it’s adpressed in A. mvuvii.

Distribution based on Regional Taxon Lists
Afrotropical Region: Botswana, Burundi, Central African Republic, Congo, Democratic Republic of Congo, Eritrea, Ethiopia, Kenya, Mozambique, South Africa, Swaziland, Uganda, Zimbabwe.

Nomenclature

 * . Aenictus eugenii Emery, 1895h: 17, pl. 2, figs. 1-4 (w.) SOUTH AFRICA.
 * Type-material: holotype worker.
 * Type-locality: South Africa: Makapan, i.-iv.1893 (E. Simon).
 * Type-depository: MSNG.
 * [Misspelled as eugeniae by Arnold, 1915: 139, and others.]
 * Gotwald & Cunningham-Van Someren, 1976: 183 (q.).
 * Status as species: Emery, 1895j: 747; Wasmann, 1904b: 676; Emery, 1910b: 31; Forel, 1911e: 255; Arnold, 1915: 139 (redescription); Wheeler, W.M. 1922a: 752; Prins, 1963: 97; Gotwald & Cunningham-Van Someren, 1976: 183; Bolton, 1995b: 59; Hita Garcia, et al. 2013: 201.
 * Senior synonym of kenyensis: Gotwald & Cunningham-Van Someren, 1976: 183; Bolton, 1995b: 59.
 * Distribution: Democratic Republic of Congo, Kenya, South Africa, Zimbabwe.
 * brazzai. Aenictus eugenii var. brazzai Santschi, 1910c: 355 (w.) CONGO.
 * Type-material: 11 syntype workers.
 * Type-locality: Congo (“Congo français”): Brazzaville, 1.xii.1906 (A. Weiss).
 * Type-depository: NHMB.
 * Subspecies of eugenii: Wheeler, W.M. 1922a: 752.
 * Status as species: Santschi, 1924b: 204; Bolton, 1995b: 59.
 * Junior synonym of eugenii: Gomez, 2022: 26.
 * Distribution: Congo.
 * caroli. Aenictus eugenii subsp. caroli Forel, 1910c: 248 (w.) ERITREA.
 * Type-material: syntype workers (number not stated).
 * Type-locality: Eritrea: Nefassit, 1906 (K. Escherich).
 * Type-depositories: MHNG, NHMB.
 * Subspecies of eugenii: Wheeler, W.M. 1922a: 752; Finzi, 1939a: 162; Bolton, 1995b: 59; Madl, 2019: 13.
 * Junior synonym of eugenii: Gomez, 2022: 26.
 * Distribution: Eritrea.
 * henrii. Aenictus eugenii var. henrii Santschi, 1924b: 204 (w.) DEMOCRATIC REPUBLIC OF CONGO.
 * Type-material: 4 syntype workers.
 * Type-locality: Democratic Republic of Congo (“Congo belge”): Kidada, nr Kitobola (H. Schouteden).
 * Type-depository: NHMB.
 * Subspecies of eugenii: Bolton, 1995b: 59.
 * Junior synonym of eugenii: Gomez, 2022: 26.
 * Distribution: Democratic Republic of Congo.
 * kenyensis. Aenictus eugeniae var. kenyensis Santschi, 1933b: 100 (w.) KENYA.
 * Type-material: 15 syntype workers.
 * Type-locality: Kenya: Kiambou, 27.ii.1929, no. 180, attending Pseudococcus lilacinus (Le Pelley).
 * Type-depositories: BMNH, NHMB.
 * Junior synonym of eugenii: Gotwald & Cunningham-Van Someren, 1976: 183; Bolton, 1995b: 60.

Type Material

 * Aenictus eugenii
 * Syntype worker, SOUTH AFRICA, [CASENT0903759, seen on web]; Syntype A. eugenii, no loc. data (1w) MHNG [Examined by Gomez, 2022].
 * Aenictus eugenii brazzai
 * Syntype workers (3w), CONGO: Brazzaville 01.dec.1906 (Weiss) (3w) [CASENT0911418] NHMB [Examined by Gomez, 2022]; Syntype, same data, (2 pins, 1w each) MHNG [Examined by Gomez, 2022]; Syntype, same data, (2 pins, 1w each) [MRACFOR000016, MRACFOR000017] MRAC [Examined by Gomez, 2022]; same data, not labelled as type (2w, 3w) NHMB [Examined by Gomez, 2022]; same data, not labelled as type (3w) [EY19928] MNHN [Examined by Gomez, 2022].
 * Aenictus eugenii caroli
 * Syntype worker, ERITREA: Nefassit (1w) NHMB [Examined by Gomez, 2022]; Syntype, Nefassit (Escherich) (1w) NHMB [Examined by Gomez, 2022]; Syntype, Erythraea (4w) (Escherich) NHMB [Examined by Gomez, 2022]; Syntype, Nefassit (Escherich) (3w) MHNG [Examined by Gomez, 2022], Syntype, same data (2w) [CASENT0907026] MHNG [Examined by Gomez, 2022].
 * Aenictus eugenii henrii
 * Syntype worker, DEMOCRATIC REPUBLIC OF CONGO: Kidada (Kitobola) 14-25.ii.1922 (Dr. H. Schouteden) (1w) [CASENT0911423] NHMB [Examined by Gomez, 2022]; Syntype, same data (15 pins, 1w each) [MRACFOR000018 to MRACFOR000032] MRAC [Examined by Gomez, 2022].
 * Aenictus eugeniae kenyensis
 * Syntype worker, KENYA: Kiambou (La Pelley) (8w) [CASENT0902686] NHMB [Examined by Gomez, 2022]; Syntypes, Liambu 27/02/1929 (R. H. Le Pelley) (3w each) [NHMUK012849233, NHMUK012849234] BMNH [Examined by Gomez, 2022].

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.
 * Baroni Urbani C. 1977. Katalog der Typen von Formicidae (Hymenoptera) der Sammlung des Naturhistorischen Museums Basel (2. Teil). Mitt. Entomol. Ges. Basel (n.s.) 27: 61-102.
 * Borowiec M. L. 2016. Generic revision of the ant subfamily Dorylinae (Hymenoptera, Formicidae). ZooKeys 608: 1–280.
 * Forel A. 1911. Die Ameisen des K. Zoologischen Museums in München. Sitzungsber. Math.-Phys. Kl. K. Bayer. Akad. Wiss. Münch. 11: 249-303.
 * Gotwald W. H., Jr.; Cunningham-van Someren, G. R. 1976. Taxonomic and behavioral notes on the African ant, Aenictus eugenii Emery, with a description of the queen (Hymenoptera: Formicidae). Journal of the New York Entomological Society 84:182-188.
 * Gotwald, W. H., Jr.; Cunningham-van Someren, G. R. 1976. Taxonomic and behavioral notes on the African ant, Aenictus eugenii Emery, with a description of the queen (Hymenoptera: Formicidae). Journal of the New York Entomological Society 84:182-188.
 * Hita Garcia F., E. Wiesel, G. Fischer. 2013. The ants of Kenya (Hymenoptera: Formicidae)faunal overview, first species checklist, bibliography, accounts for all genera, and discussion on taxonomy and zoogeography. Journal of East African Natural History 101: 127-222.
 * IZIKO South Africa Museum Collection
 * 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.
 * Santschi F. 1910. Formicides nouveaux ou peu connus du Congo français. Annales de la Société Entomologique de France 78: 349-400.
 * Santschi F. 1933. Contribution à l'étude des fourmis de l'Afrique tropicale. Bulletin et Annales de la Société Entomologique de Belgique. 73: 95-108.
 * Ward P. S. 2007. The ant genus Leptanilloides: discovery of the male and evaluation of phylogenetic relationships based on DNA sequence data. Memoirs of the American Entomological Institute 80: 637-649.
 * 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