Dorylus wilverthi

A sub-Sarahan driver ant.

Identification
A member of the Dorylus nigricans-group.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Central African Republic, Democratic Republic of Congo, Ivory Coast, Kenya, Uganda.

Biology
Dorylus wilverthi is a driver ant.

Butler et al. (2018) - Driver ant are a group of nomadic swarm-raiding army ants that are restricted to sub-Saharan Africa (Wilson, 1964; Gotwald, 1995). The group is comprised of approximately nine species (Kronauer et al., 2007; Scheoning, 2008) in the subgenus Anomma. Driver ants are top invertebrate predators with extremely large colonies that can contain more than 10 million workers (Gotwald, 1995). Unlike the queens of most other ants, army ant queens are permanently wingless. Instead of going on a mating flight, new queens mate within their natal nest with approximately 10–30 unrelated males that disperse on the wing. In driver ants, mating probably occurs within a 2- to 3-week period before the new queen assumes regnancy of her colony (Kronauer et al., 2004b; Kronauer & Boomsma, 2007), and the mother queen disperses on foot, taking a portion of the existing workers with her (Gotwald, 1995). Colonies of driver ants are monogynous, and queens are highly multiply mated.

In Kakamega Forest, Kenya this species co-occurs with Dorylus nigricans molestus (Garcia et al., 2009; Peters & Okalo, 2009; Kronauer et al., 2011; Peters et al., 2011). Dorylus wilverthi mainly inhabits intact rainforest habitat (Scheoning et al., 2006; Peters & Okalo, 2009; Peters et al., 2009).

Hybridization
Butler et al. (2018) found this ant and the co-occuring Dorylus nigricans molestus hybridize. Their study of the population genetics of naturally occurring colonies concluded: "hybridization is bidirectional and occurs at equal rates in both species. Hybrid workers make up only 1–2% of the population, and successful interspecific matings represent approximately 2% of all matings in both species. This shows that, although interspecific matings that give rise to worker offspring occur regularly, they are much rarer than intraspecific mating. Finally, we find no evidence of an association between hybridization and genetic caste determination in this population. This means that genetic caste determination is not a necessary outcome of hybridization in ants, even in species where queens mate with multiple males.

Nomenclature

 *  wilverthi. Dorylus (Anomma) wilverthi Emery, 1899e: 459, fig. (w.) DEMOCRATIC REPUBLIC OF CONGO. Forel, 1909b: 51 (m.); Raignier & Boven, 1955: 86 (q.); Wheeler, G.C. 1943: 321 (l.). Senior synonym of nomadas: Raignier & Boven, 1955: 93; of nigritarsis: Boven, 1972: 144. See also: Wheeler, G.C. & Wheeler, J. 1984: 268; Raignier & Boven, 1955: 115. [This name frequently misspelled as wilwerthi, for example by Santschi, 1910c: 352.]
 * nigritarsis. Dorylus nigritarsis Strand, 1911: 118 (q.) CAMEROUN. Combination in D. (Anomma): Santschi, 1915c: 248. Junior synonym of nigricans: Wheeler, W.M. 1922a: 737; of wilverthi: Boven, 1972: 144.
 * nomadas. Dorylus (Anomma) nomadas Santschi, 1935a: 254, fig. 1 (q.) DEMOCRATIC REPUBLIC OF CONGO. Junior synonym of wilverthi: Raignier & Boven, 1955: 93.