Cladistics Cladistics (2014) 1–24 10.1111/cla.12084 First phylogenetic analysis of the family Neriidae (Diptera), with a study on the issue of scaling continuous characters Nicolas Mongiardino Kocha,*, Ignacio M. Sotoa,b and Martın J. Ramırezc aDepartamento de Ecologıa, Genetica y Evolucion, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon II (C1428 EHA), Buenos Aires, Argentina; bInstituto de Ecologıa, Genetica y Evolucion de Buenos Aires (IEGEBA) – CONICET, Buenos Aires, Argentina; cMuseo Argentino de Ciencias Naturales – CONICET, Buenos Aires, Argentina Accepted 15 May 2014 Abstract Neriidae are a small family of acalyptratae flies, mostly distributed in the tropics. Very little is known about their biology, and the evolutionary relationships among species have never been evaluated. We perform the first comprehensive phylogenetic analysis of the family, including 48 species from all biogeographic regions inhabited, as well as five species of Micropezidae and one Cypselosomatidae as outgroups. We build a morphological data matrix of 194 characters, including 72 continuous charac- ters. We first explore ways to deal with the issue of scaling continuous characters, including rescaling ranges to unity and using implied weighting. We find that both strategies result in very different phylogenetic hypotheses, and that implied weighting reduces the problem of scaling, but only partially. Furthermore, using implied weighting after rescaling characters improves the congruence between partitions and results in higher values of group support. With respect to the Neriidae, we confirm the monophyly of the family and of most its genera, although we do not obtain any of the currently accepted suprageneric groups. We propose to restrict the Eoneria and Nerius groups exclusively to the Neotropical fauna, and synonymize Glyphidops subgenus Oncopsia Enderlein with Glyphidops subgenus Glyphidops Enderlein, eliminating the subgeneric divisions. This revised phylogeny presents a striking biogeographic consistency, and shows that previous main divisions of the family were based on events of con- vergence. © The Willi Hennig Society 2014. Introduction Neriidae were historically considered by some as an independent family closely related to the Micropezi- Neriidae are a small family of acalyptratae flies dae (Hendel, 1922; Cresson, 1930), while others characterized by an elongated porrect antennae with regarded them as a subfamily included within the Mi- an apical to subapical arista, and a pedicel divided cropezidae (Enderlein, 1922; Hennig, 1934, 1936, into a body and a finger-like projection that connects 1937). Consensus on the placement of this clade at with the median region of the first flagellomere (Aczel, the family level was reached only after the thorough 1961; Steyskal, 1968; Buck, 2010; the general morphol- taxonomic work done by Martın L. Aczel, including ogy of these flies can be seen in Fig. 1e,f). Despite several monographs on the diversity of neriid flies being present in all biogeographic regions, most of the from all inhabited continents (Aczel, 1951, 1954a,b,c, family’s diversity is concentrated along the tropics 1955a,b,c, 1959, 1961). Neriidae are at present recog- (Steyskal, 1968, 1987a). So far, 110 species have been nized as one of the families included within the super- described and placed in 19 genera (Sepulveda et al., family Nerioidea, the monophyly of which has been 2013a), with almost two-thirds of this diversity occur- retained in several morphological and molecular ring in the New World (Eberhard, 1998). higher-level phylogenetic analyses (J. F. McAlpine, 1989; Yeates and Wiegmann, 2005; Yeates et al., *Corresponding author: 2007; Wiegmann et al., 2011). Several synapomorphies E-mail address: [email protected] are taken to support the monophyly of the Nerioidea, © The Willi Hennig Society 2014 2 N. M. Koch et al. / Cladistics (2014) 1–24 (a) (e) (f) (b) (c) (d) Fig. 1. (a) Current phylogenetic hypothesis within the family Neriidae (only genera included in the present study are shown). (b) Chaetonerius apicalis (female), a member of the Telostylinae, which lack modified antennal bases. (c) Eoneria maldonadio (female), a member of the Eoneria group that present modified antennal bases with a dull dorsal region. (d) Nerius pilifer (male), a member of the Nerius group that present modified antennal bases with a shiny dorsal region. Black arrows show the position of the modified antennal bases. Scale bars = 0.5 mm. (e) Derocepha- lus angusticollis Enderlein, 1922 (photograph R. Bonduriansky). (f) Odontoloxozus longicornis Coquillet 1904 (photograph N. Richter). including the peculiar morphology of the elongated Aczel (1954a, 1961) was mainly responsible for male and female genitalia and the desclerotized lower erecting the modern systematic structure of the Nerii- region of the face (Aczel, 1951; J. F. McAlpine, 1989; dae, although Enderlein (1922) first defined some of D. K. McAlpine, 1996; Yeates et al., 2007; Buck and the suprageneric clades that remain currently valid. As McAlpine, 2010). However, the internal taxonomic a result, the family is divided in two subfamilies: the and systematic organization of the clade is still highly Neriinae, characterized by the presence of antennal controversial. The most conservative view recognizes sockets (also called antennal bases), formed by the only three families within the Nerioidea (J. F. protruding and more or less inflated frontal region of McAlpine, 1989): the extremely diverse Micropezidae the upper face (also referred to as mesofacial plate), (often subdivided into several subfamilies, see D. K. into which the antennae are inserted; and the basal McAlpine, 1974; Marshall, 2010), and the less diverse Telostylinae, which lack this type of antennal bases. sister taxa Cypselosomatidae and Neriidae. The However, much confusion has subsequently arisen monophyly of the Cypselosomatidae + Neriidae clade from this division, and many authors doubt that they was originally proposed by J. F. McAlpine (1989), constitute monophyletic groups (Pitkin, 1989; Barrac- and has found subsequent confirmation in a recent lough, 1993a; Buck, 2010). The entirety of the Ameri- molecular phylogeny (Wiegmann et al., 2011). Other can fauna belongs to the subfamily Neriinae, which authors have proposed separating Pseudopomyzidae Aczel (1961) further subdivided into two groups: the from Cypselosomatidae and establishing this group as Nerius group, among which the dorsal region of the a fourth family (D. K. McAlpine, 1966; Shatalkin, antennal bases is polished and shiny; and the Eoneria 1994), although many have favoured a subfamiliar group, in which the antennal bases are dull, and have rank for the two (Griffiths, 1972; Prado, 1984; J. F. at most a faint greasy luster. Furthermore, some McAlpine, 1987, 1989). authors (Aczel, 1961; Buck and Marshall, 2004; Buck, N. M. Koch et al. / Cladistics (2014) 1–24 3 2010; Sepulveda et al., 2013a) have partially discussed have since been dealt with (Chappill, 1989; Rae, 1998), morphological similarities between the Neotropical and many authors have argued that the distinction genera Longina Wiedemann, Cerantichir Enderlein and between discrete and continuous characters is actually Odontoloxozus Enderlein, although no author has gone just a matter of degree (Stevens, 1991; Gift and Stevens, so far as to propose these genera as constituting a 1997; Wiens, 2001; MacLeod, 2002). A new reappraisal monophyletic group, and no other phylogenetic of quantitative data has followed after Goloboff et al. hypothesis has been put forward. A summary of all (2006) implemented the treatment of continuous charac- these proposed relationships can be found in Fig. 1. ters as such in the software TNT (Tree analysis using Ever since the mid-twentieth century, few taxonomic New Technology; Goloboff et al., 2008b). Since then, works have been published on the family. A handful of factual evidence that continuous characters carry useful papers have dealt with the description of some new spe- phylogenetic information has accumulated (Goloboff cies (Mangan and Baldwin, 1986; Buck and Marshall, et al., 2006; Hornung-Leoni and Sosa, 2008; Pereyra 2004; Sepulveda et al., 2013b), but the systematic rela- and Mound, 2009; de Bivort et al., 2010; Escapa and tionships within the family have never been re-evaluated Catalano, 2013). or tested using matrix-based phylogenetic methods. The Despite proving useful in many cases, some methodo- family does present some peculiarities that have been logical caveats concerning the implementation of con- interpreted by some as impediments towards a morpho- tinuous characters in parsimony analysis are still poorly logical evaluation of the relationships among genera, explored. One of such issues is scaling, which has been such as the extremely conserved male genitalia (Buck, referred to as “one of the most pervasive problems in 2010) and the outstanding intraspecific variability in the the analysis of continuous characters” (Goloboff et al., distribution of setae (Aczel, 1951; Barraclough, 1993a; 2006). As the same authors argued, although it is clear Buck, 2010), a feature that has even been addressed that within a single continuous character a change in experimentally (Bonduriansky, 2009). state between two species should be proportional to the Nonetheless, the impressive taxonomic legacy of magnitude of the difference they exhibit, the problem M. L. Aczel (summarized by Mello, 2010), including arises when