Dirini is one of the

tribes The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...

in the butterfly subfamily

Satyrinae The Satyrinae, the satyrines or satyrids, commonly known as the browns, are a subfamily of the Nymphalidae (brush-footed butterflies). They were formerly considered a distinct family, Satyridae. This group contains nearly half of the known divers ...

of the family

Nymphalidae The Nymphalidae are the largest family of butterflies, with more than 6,000 species distributed throughout most of the world. Belonging to the superfamily Papilionoidea, they are usually medium-sized to large butterflies. Most species ha ...

. Consisting of 29 species in 6 genera, the group's members are exclusively found in southern Africa. Initially distinguished by having a forewing

cell Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a de ...

length shorter than half the length of the forewing, the morphological synapomorphy that links the members of the Dirini together is the presence of the scaphium on the male genitalia. The group is remarkable for its restricted distribution within

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and

Lesotho Lesotho, formally the Kingdom of Lesotho and formerly known as Basutoland, is a landlocked country in Southern Africa. Entirely surrounded by South Africa, it is the largest of only three sovereign enclave and exclave, enclaves in the world, t ...

, with a single species whose distribution extends into

Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...

. It is closely affiliated with the tribe

Melanitini The Melanitini (evening browns and relatives) are one of the smaller tribes of the Satyrinae in the Nymphalidae (brush-footed butterfly) family. They contain the following genera: * '' Aphysoneura'' Karsch, 1894 - sometimes placed in Elymniini ...

, of whom the Neotropical '' Manataria hercyna'' is closest related to the Dirini as a whole.

Description

Members of the tribe are endemic to southern Africa, with the group consisting of 29 species in 6 genera. The larvae of the members feed on grasses. First characterized by Miller in 1968 as exhibiting a forewing cell length shorter than half of the length of the

forewing Insect wings are adult outgrowths of the insect exoskeleton that enable insects to fly. They are found on the second and third thoracic segments (the mesothorax and metathorax), and the two pairs are often referred to as the forewings and hindwi ...

, this feature united the genera of ''Dira'', ''Dingana'', ''Serradinga'', ''Torynesis'' and ''Tarsocera''. This circumscription excluded ''Aeropetes'' or ''Paralethe'', which were alternatively placed into Lethini by Miller in 1968,

Elymniini The Elymniini is one of the tribe (biology), tribes of the subfamily Satyrinae. If the subfamily Satyrinae elevate to family (biology), family status, this tribe shall be treated as subfamily Elymniinae. Elymniini was formerly a large group, but ...

by Ackery ''et al.'' in 1995, and Melanitini by Peña ''et al.'' in 2005. Phylogenetic analysis in 2010 by Price ''et al.'' confirmed their continued placement within the Dirini. The presence of a scaphium on the male genitalia was identified as the sole morphological

synapomorphy In phylogenetics, an apomorphy (or derived trait) is a novel Phenotypic trait, character or character state that has evolution, evolved from its ancestral form (or Plesiomorphy and symplesiomorphy, plesiomorphy). A synapomorphy is an apomorphy sh ...

which united the group.

Systematics and taxonomy

Per Peña & Wahlberg, 2008, the tribe is around 25 million years old. The divergence of Dirini and Melanitini occurred between 23 and 47

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

(Ma). The initial point of radiation for the tribe was just before or at the Oligocene-Miocene transition around 29-24 Ma. The seven genera of the tribe were described as "convincingly

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

" by Price ''et al.'', reflected in the morphological and biological homogeneity of the genera that contain more than a single species, with the relative diversity in the morphological and biological sense between the various genera. The most stable group within the Satyrinae is the sister group relationship between Dirini and

, having been recovered in studies by Peña ''et al.'' 2006, Peña and Wahlberg 2008, Wahlberg ''et al.'' 2009, and Price ''et al.'' 2010. '' Manataria hercyna'' was confirmed to be a

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of the tribe, with that relationship supported by previous analyses Peña ''et al.'' in 2006, and Peña & Wahlberg in 2008. Studies showed that ''Manataria'' would be placed into the Melanitini, but its placement would render Melanitini

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

, which suggests that it would be best to either place ''Manataria'' into its own tribe or within the Dirini. The relationship between ''Manataria'' and the remainder of the Dirini was described by Price ''et al.'' as "odd", due to the former's

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

distribution compared to the tribe's

Afrotropical The Afrotropical realm is one of the Earth's eight biogeographic realms. It includes Sub-Saharan Africa, the southern Arabian Peninsula, the island of Madagascar, and the islands of the western Indian Ocean. It was formerly known as the Ethiopi ...

distribution, and its estimated divergence from the remainder of the tribe 40 Ma from the present. This would mean that divergence had occurred when South America was several thousand kilometers from the African coast, which is a process that has occurred similarly for the amphisbaenid lizards, platyrrine monkeys and caviomorph rodents, suggesting an underlying process in a westward direction. The following phylogenetic trees are adapted from Wahlberg and Brower, 2011:

Distribution

Members of the tribe are noted for their remarkable degree of endemism, being found almost exclusively in

and

, with a single member whose distribution extends into eastern

. They are almost all found on high-lying ground, but are described by Price ''et al.'' as not a truly montane group, occurring on slopes from the south and east and from elevations at in the north and west. Members of the tribe are found in South Africa's

Succulent Karoo The Succulent Karoo is an terrestrial ecoregion, ecoregion defined by the World Wide Fund for Nature to include regions of deserts and xeric shrublands, desert in South Africa and Namibia, and a biodiversity hotspot. The geographic area chosen ...

region and grasslands, which are dominated by C3 producing grasses, with the exception of '' Paralethe dendrophilus'', which inhabits coastal and Afromontane forests.

Genera

Genus, species, and subspecies list derived from Price ''et al.'' 2010, and Williams 2018. Price ''et al.'' recognizes ''Torynesis hawequas'' as a subspecies of ''Torynesis mintha'' (as ''Torynesis mintha hawequas''), while Williams recognizes it at full species status. Genomic testing conducted in 2023 by Zhang ''et al.'' revealed that ''Serradinga'' was better suited as a subgenus of ''Dingana''.

Footnotes

References

{{Taxonbar, from1=Q11965748, from2=Q55392097 Dirini Satyrinae Butterfly tribes Taxa named by Ruggero Verity