73 (2): 303 – 321 20.8.2015 © Senckenberg Gesellschaft für Naturforschung, 2015. A molecular phylogeny of the African Scarabaeinae (Coleoptera: Scarabaeidae) Sukoluhle Mlambo *, Catherine L. Sole & Clarke H. Scholtz Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028 Pretoria, South Africa; Sukoluhle Mlambo * [[email protected]]; Catherine L. Sole [[email protected]]; Clarke H. Scholtz [[email protected]] — * Correspond­ ing author Accepted 25.vi.2015. Published online at www.senckenberg.de/arthropod­systematics on 07.viii.2015. Abstract Dung beetles of the subfamily Scarabaeinae have a worldwide distribution, with the Afrotropical region, the putative origin of the diversifi- cation of Scarabaeinae, having the richest diversity. We use partial sequences from two ribosomal (16S, 28S) and two protein coding genes (COI, CAD) to examine the relationships among 55 genera, representing more than half of the genera in the region. Taxa were sampled to maximize representation of dung beetle morphological and ecological diversity in all nine tribes that occur in Africa. We estimated the di- vergence times of the tribes to determine relative ages. The phylogenetic hypothesis of tribal and generic relationships was found to largely concur with that of a recent molecular study done at a global scale, suggesting earliest diverging lineages which are quite distinct from the ones traditionally recognized. Thus recent calls for a new classification for Scarabaeinae are supported. We suggest possible changes to the classification, corroborate the likely African origin of the subfamily and provide support for fungus-feeding as the most likely ancestral feeding habit in the Scarabaeinae. Key words Afrotropical, Scarabaeinae, molecular, phylogeny, divergence. 1. Introduction The subfamily Scarabaeinae constitutes a group of Scarabaeinae is a monophyletic group morphologi- dung beetles encompassing approximately 5700 species cally defined by twelve shared apomorphic character (SCHOLTZ et al. 2009). These beetles have a world-wide states of hindwing articulation (BROWNE & SCHOLTZ distribution with most being associated with moist herbi- 1998) and also strongly supported by molecular evidence vore dung. Some, however, utilise a variety of other dung (PHILIPS et al. 2004; OCAMPO & HAWKS 2006; MONAGHAN types and even non-dung food sources. Dung is a highly et al. 2007). It is generally assumed that the sister group nutritious but patchy and ephemeral resource, character- of the Scarabaeinae is the similar dung-feeding Aphodii- istics that, together with intense competition at the dung nae (PHILIPS et al. 2004; MONAGHAN et al. 2007; BROWNE pat, have led to the evolution of an impressive range of & SCHOLTZ 1999). The 227 genera in Scarabaeinae have morphological attributes (such as horns, modifications been grouped in a number of different ways with earlier of the tibiae, bright metallic colours, complex sculpture) classifications having been based on personal intuition and behaviours, in terms of feeding and nesting in dung or morphology from limited data sets (ZUNINO 1983; beetles (DAVIS & SCHOLTZ 2001). Scarabaeines are of bio- 1985). Traditionally, the subfamily has been divided into logical interest for these attributes and for their impor- two groups based on either their rolling or tunnelling tant role in ecosystem functioning (NICHOLS et al. 2008; behaviour (BALTHASAR 1963; CAMBEFORT 1991a). Roll- BROWN et al. 2010). ers construct balls of dung and bury them at a distance ISSN 1863-7221 (print) | eISSN 1864-8312 (online) 303 Mlambo et al.: Molecular phylogeny of the African Scarabaeinae from the source for feeding and breeding, while tunnel- from the two-clade scenario, with the relationships within lers bury dung beneath or near the dung pat. JANSSENS the ingroup differing from the earlier mentioned stud- (1949) grouped the scarabaeines into six tribes: rolling ies. Rollers and tunnellers were intermixed within the Eurysternini and Scarabaeini, the latter with subtribes phylogenetic tree and, although some Ateuchini genera Eucraniina, Canthonina, Gymnopleurina, Scarabaeina originated from basal dichotomies within the tree, oth- and Sisyphina; and tunnelling Onthophagini, Onitini, ers did not. There was, however, generally poor support Oniticellini and Coprini, the latter with subtribes Di- for most nodes at the base of their tree, with no evidence chotomiina, Phanaeina and Ennearabdina. BALTHASAR’s for the monophyly of the ateuchines, coprines and del- (1963) division of the group (therein ranked as a family, tochilines. Monophyly was supported to some extent for Scarabaeidae) was into two subfamilies with six tribes the remaining nine tribes (an average of only two genera each, as follows: Coprinae with tribes Coprini, Ateuchi- per tribe were used). From this study it was concluded ni, Phanaeini, Oniticellini, Onitini and Onthophaghini; that the Scarabaeinae ancestor was a tunneller, with all and Scarabaeinae with tribes Eucraniini, Eurysternini, other clades having evolved directly or indirectly from Deltochilini, Gymnopleurini, Scarabaeini and Sisyphini. an Ateuchini-like ancestor, and rolling having evolved This grouping by BALTHASAR (1963) was followed by independently a number of times. Furthermore, the study many workers on the Scarabaeinae. These include HAN­ suggests that according to biogeographical evidence, SKI & CAMBEFORT (1991), who further envisioned the Del- some Scarabaeinae taxa may have been present in the tochilini and Ateuchini (formerly Dichotomiini) as the Mesozoic, consistent with fossil evidence from a study by primitive or “old” tribes that gave rise to the rest of the KRELL (2006) suggesting a late Mesozoic origin for dung rollers and tunnellers, respectively. The tribes Scarabaei- beetles. SCHOLTZ & CHOWN (1995) on the other hand had ni, Gymnopleurini, Eucraniini, Eurysternini, Onitini and proposed the Cenozoic epoch for the most recent dung Phanaeini were considered to be “intermediate” in age beetle ancestor. In a recent morphological study TARASOV (CAMBEFORT 1991a). Sisyphini were considered the most & GÉNIER (2015) used 110 taxa and 205 characters to hy- modern/derived of the rollers and Coprini, Oniticellini pothesize a phylogeny that is consistent with the results and Onthophagini the most recently evolved tunnellers from different studies while also suggesting new relation- (CAMBEFORT 1991a). It was, however, an intuitive clas- ships especially among Deltochilini and Dichotomiini. sification, lacking in phylogenetic support (MEDINA et al. The Scarabaeinae study by VILLALBA et al. (2002) was 2003; PHILIPS et al. 2004; MONAGHAN et al. 2007). The the first to use molecular data on the group. It was based current classification divides the subfamily into 11 tribes on the DNA sequences of the mitochondrial cytochrome (BOUCHARD et al. 2011): Ateuchini, Deltochilini, Eucra- oxidase I and II genes (COI, COII). Thirty-three species niini, Gymnopleurini, Oniticellini (including former Eu- representing the seven tribes and all the genera occurring rysternini as a subtribe), Onitini, Coprini, Onthophagini, in the Iberian Peninsula were used in the analysis. VILL­ Phanaeini, Scarabaeini, and Sisyphini. ALBA et al. (2002) showed a contradiction to the accepted Early phylogenetic studies such as that of ZUNINO classification, with Coprini, a tunneller, placed among the (1983), using morphological data for cladistic analyses, rolling tribes in their phylogeny, though with poor sup- indicated problems with the roller/tunneller division; port. This study, however, relied solely on mitochondrial there was evidence of tunneller groups nested within the genes whereas the current trend is to use both mitochon- rollers. In addition, the tribes Deltochilini and Ateuchini drial and nuclear genes to produce a more reliable phylo- did not appear to arise from basal phylogenetic dichoto- genetic tree. Mitochondrial genes are fast evolving and mies. MONTREUIL (1998) used 42 adult morphological useful for comparisons of closely related taxa while nu- characters for his study of the Ateuchini and Coprini and clear genes are slowly evolving and suitable for compari- found the two tribes to be non-monophyletic. He sug- sons of distantly related taxa (SIMON et al. 1994). Further- gested major changes to scarabaeine classification. The more, it is desirable to use several markers of independent tribe previously known as Dichotomiini was renamed At- evolutionary history (WAHLBERG & WHEAT 2008). euchini Perty after reassigning some genera to Coprini. OCAMPO & HAWKS (2006) used two ribosomal nuclear Another phylogenetic analysis to raise serious doubts genes for their reconstruction of the scarabaeine phyloge- about the then accepted dung beetle classification B( AL­ ny. They included genera from all tribes except Sisyphini THASAR 1963) was that by PHILIps et al. (2004). Their and Gymnopleurini. Again inconsistencies were found study was based on 200 morphological characters and 50 among sister relationships of the tribes. taxa covering all 12 tribes recognised then, sampled from To date, MONAGHAN et al. (2007) have performed six biogeographical regions. The tribes comprise Del- the most extensive molecular phylogenetic study on the tochilini and Ateuchini, which are widespread with their Scarabaeinae using 214 species, sampled from across the main generic diversity in the southern continents (Neo- world. They used three gene regions, two mitochondrial tropical, Afrotropical