The genus Oleria (Hübner, 1816) is the most speciesrich within the tribe Ithomiini, with 49 known species distributed from Mexico to northern Argentina (De-Silva et al. 2016). The genus reaches its highest species richness in the eastern Andes and upper Amazon (Chazot et al. 2016), engages in several different mimicry rings (e.g., Beccaloni 1997) and individual species can present quite different color patterns across their geographic range (De-Silva et al. 2010, Warren et al. 2015). The Amazonian species Oleria gunilla (Hewitson, 1858) is a good example; its eight described subspecies are quite different in color pattern, representing at least six different mimicry rings (Chazot et al. 2016; see also Warren et al. 2015).

About a decade ago, the first author received some specimens of butterflies collected in the southwestern Amazon, along the Mureru River, northern Mato Grosso State, central Brazil, including a large sample of ithomiines. Among them were four specimens of an unknown ‘orange-tip’ Oleria taxon. In the present paper, we describe this taxon as a new subspecies of Oleria gunilla, based on morphological and molecular characters, and discuss its mimetic relationships.

Material and Methods

Specimens of Oleria were studied in several field locations in the Neotropics (KRW and AVLF) and examined in major public and private collections in Europe, North and South America, including types of all Oleria gunilla taxa and names. Distribution data for examined specimens were compiled in a database to permit study of related taxa and mimicry patterns. In addition, we also examined the Lamas collection of neotropical butterfly type specimen photographs at the MUSM (also available online in Warren et al. 2015), representing all relevant names of Oleria (see Lamas, 2004). Morphology was studied using standard techniques, with adult abdomens being soaked in hot 10% KOH for 10–15 minutes, dissected and subsequently stored in glycerin. The following collection acronyms are used in the text: ZUEC, Museu de Zoologia da Universidade Estadual de Campinas, Unicamp, Campinas, São Paulo, Brazil; ZUEC-AVLF, André V. L. Freitas Collection, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.

Total genomic DNA was isolated from four individuals of the putative new subspecies of Oleria gunilla using Invisorb® Spin Tissue Mini Kit (STRATEC Molecular, Germany). The barcode region proposed by Hebert et al. (2003), which is the 5′ portion of the mitochondrial DNA (mtDNA) gene cytochrome oxidase subunit I (COI, 658 bp), was sequenced according to published protocols (Wahlberg & Wheat 2008). Sequences were aligned with those of other Oleria from the “amalda” group (sensu De-Silva et al. 2010) obtained from GenBank (Table 1). The final matrix comprised 50 individuals of the six species of Oleria from the “amalda” group and one individual of Oleria vicina as outgroup. Bayesian analyses (BI) were carried out using the program MrBayes 3.2 (Ronquist & Huelsenbeck 2003) on the CIPRES portal (Miller et al. 2010). The model-jumping feature of the program was utilized, thereby sampling all possible GTR submodels according to their posterior probability (Ronquist et al. 2012). The gamma parameter was also included to allow site rate variation. Four simultaneous chains were run for 10×106 generations for two runs, sampling trees every 1,000 cycles. The first 2,500 trees were discarded as “burn in” based on when the runs had converged and reached equilibrium. The convergence of the likelihood traces of the independent runs was assessed with TRACER v1.5, and the ESS (effective sample size) values were verified to be above 300 for all parameters, which indicates that they were sufficiently sampled to estimate their posterior distributions (Drummond et al. 2006).

Fig. 1.

Oleria gunilla lourdes - holotype male. Dorsal above, ventral below.

Discussion

The wing pattern of O. gunilla lourdes, with such a broad expanse of orange, resembles the AURELIANA mimicry pattern (Willmott & Mallet 2004), which is typical of the upper Amazon and Andean foothills of Peru, Colombia and Ecuador (Fig. 4). Thus, this taxon appear to be misplaced in terms of its mimicry ring - the type locality in Northern Mato Grosso is more than 600 km distant from any other locality where similarly patterned ithomiines are found (Fig. 4). In addition, in a large sample of more than 25 Ithomiini species from the same locality, not a single species with a similar mimetic pattern was observed, an unexpected fact considering that local convergence in mimetic patterns has been long known for aposematic butterflies (Müller 1879). Most strikingly, the extent of orange wing markings in this subspecies is one of the largest within the whole tribe, mirrored in very few other ithomiines (Warren et al. 2015). Although no other local Ithomiini converge in mimicry pattern with O. gunilla lourdes, candidate co-mimic butterflies not reported in the type locality could include some Riodinidae, such as species of Stalachtis Hübner, 1818, or classical mimetic Pieridae such as Dismorphia theucharila (E. Doubleday, 1848). This atypical situation surely deserves further investigation in depth, including additional fieldwork to uncover possible sympatric mimetic species of O. gunilla lourdes.

Fig. 2.

Oleria gunilla lourdes - male genitalia. Lateral on top, dorsal at middle, aedeagus at bottom. Abbreviations: ae - aedeagus; cn - cornutus; sa - saccus; ta - tuba analis; tg - tegumen; un - uncus; va - valva.

Table 1

- Species of Oleria with code, sampling sites data, and GenBank accession numbers for sequenced genes.

Continued

Fig. 3.

Bayesian Inference tree for the “amalda” species group of Oleria, including the four specimens of Oleria gunilla lourdes new ssp. Posterior probabilities of nodes are presented below the nodes.

Fig. 4.

Distribution of the ithomiine species belonging to the AURELIANA mimicry pattern in the Neotropics (solid circles). The location of the type locality of O. gunilla lourdes is indicated.