Review of Euptychiina Systematics and Biology
The Satyrinae is one of the most diverse nymphalid subfamilies, with 2600 species occurring on all continents except Antarctica (Ackery et al., 1999), and the Euptychiina is an almost entirely Neotropical subtribe of the most diverse tribe, the global Satyrini (Peña & Wahlberg, 2008). Most euptychiines are small with dark brown wings marked by a few simple ocelli, although several genera have white or brilliant blue wings. The majority of euptychiines are lowland species, except for the largely Andean Forsterinaria (Peña & Lamas, 2005). Community diversity peaks in the W. Amazon, where 100 species can coexist (Lamas et al., 1991; Brown, 1996), while the Atlantic region of Brazil also has a diverse, endemic fauna. A single Asian genus, Palaeonympha, is also apparently a euptychiine (Miller, 1968; Peña et al., 2006, 2010).
Moderately detailed descriptions of early stages have been published for only 20 species (5% of the subtribe) (Müller, 1886; Singer et al., 1983; Young, 1984; Murray, 2001, 2003; Freitas, 2003, 2004a,b, 2007; Freitas & Peña, 2006; Kaminski & Freitas, 2008), and hostplant records are similarly scarce. Like most satyrines, larvae of most species feed on Gramineae, grasses and bamboo (Beccaloni et al., 2008), with some records on Cyperaceae and Marantaceae, except for Euptychia which feed on mosses and lycopsids (Singer et al., 1971; Singer & Mallet, 1986; DeVries, 1986; Brévignon, 2008). Development times are relatively long among tropical butterflies, up to three months or more (Freitas, unpub. data from > 50 species and 27 genera). Eggs are generally isolated and lack chorionic sculpturing. Larvae have bifid “tails” and may bear head horns that vary in size. Pupae are generally short, squat and smooth. Adults are rarely encountered at nectar, but often feed on decaying fruits or tree sap, and on carrion and animal feces. Some species are crepuscular (e.g. Taygetis, Murray, 2003), and males of forest species patrol territories in the understory, often on ridgetops, in the late afternoon (Peixoto & Benson, 2009; Willmott, pers. obs.). Males often bear tufts of hair-like scales or other androconia on the wings that presumably function in courtship.
The current classification includes more than 400 species (Lamas, 2004; Freitas, Willmott, unpub.; Huertas et al., 2009; Peña et al., 2010; Huertas, 2011; Pulido et al., 2011; Brévignon & Benmesbah, 2011; Matos et al., 2012; Freitas et al., 2011, 2012; Zacca et al., 2013) in 42 genera, with from 1 (10 genera) to 47 species. Remarkably, 80 (20%) of the known species are undescribed, a statistic exceeded among the true butterflies only by the Lycaenidae (34%) and Pronophilina (27%) (Lamas, 2004). Most known undescribed species are distinctive but poorly represented in historical collections, and many cryptic species (e.g. Willmott & Hall, 1995) surely remain to be discovered. For example, Miller (1974) described 11 of the 28 species of Cyllopsis, and Peña and Lamas (2005) described 12 of the 23 species in Forsterinaria. Most inventories contain undetermined species (e.g. Brévignon, 2005, 2007, 2008; Brévignon & Benmesbah, 2011), with recent fieldwork in Brazil revealing 8 new species in Yphthimoides, Splendeuptychia and Moneuptychia (Freitas 2004b, 2007). Many euptychiines are externally very similar, and some are apparently highly variable; with only five euptychiine genera (15%) the subject of modern revisions (Miller, 1972, 1974, 1976, 1978; Peña & Lamas, 2005), references for generic and species identification are urgently needed.
Miller (1968) defined the subtribe by external morphology, and molecular (Murray & Prowell, 2005; Peña et al., 2006) and morphological (Marin, 2010) studies have largely confirmed the current classification (Lamas, 2004), except for excluding Oressinoma and including Amphidecta and the Asian Palaeonympha. The position of Euptychia itself, however, is still unresolved (Murray & Prowell, 2005); the most comprehensive molecular phylogeny of Euptychiina to date (Peña et al., 2010), based on 4447 bp from 5 genes, for 108 euptychiine species and 18 outgroup taxa, did not recover a monophyletic Euptychiina. However, Marin (2010) did recover the subtribe as monophyletic and found a number of clades in common with Peña et al. (2010). A major goal of our research, therefore, will be to integrate and expand these data matrices to generate a robust higher-level phylogeny for the group.
If the relationships of Euptychiina within the Satyrini are still unclear, the generic classification is arguably the most chaotic for any butterfly group of similar diversity. Weymer (1910-11) classified the majority of Neotropical species (270 spp.) as “Euptychia“, presumably because of their wing pattern homogeneity, and D’Abrera (1988) continued the trend, ignoring a large number of generic names that were introduced by Forster (1964). Forster’s diagnoses were based partly on wing pattern and male genitalia, but also on overall appearance, and his characters are often unreliable. Lamas (2004) moved almost all “Euptychia” (sensu D’Abrera) into Forster’s genera, which constitute 26 of the currently accepted 39 Neotropical genera. Although the Lamas classification is a critical framework for future work, recent cladistic analyses reveal much remaining paraphyly and polyphyly among genera (Murray & Prowell, 2005; Peña et al., 2006). Peña et al. (2010) tested the monophyly of 23 Euptychiina genera and found that only 8 (35%) are monophyletic. Often, supposed congeners occurred within different species groups, such as Splendeuptychia, whose species appear in the Splendeuptychia, Pareuptychia and Hermeuptychiaclades. Marin (2010) found similar results using morphological characters; only 10 of 22 Euptychiina genera tested (45%) proved monophyletic. Recent taxonomic revisions based on a molecular phylogeny of the nine Taygetis-clade genera resulted in the synonymy of three genera, rearrangement of three genera and revelation of two undescribed genera (Matos et al., 2012). Based on an expanded higher-level phylogeny, we hope to revise generic limits and describe useful morphological characters for generic identification.