Methona confusa has been recorded across its geographic range from low elevations up to around 2,000 m, being rare above 1,500 m. We report herein a new elevational record of M. confusa above 3,500 m, the highest ever reported for ithomiines, from upper montane area of Megantoni National Sanctuary and Manu National Park, located on the eastern slopes of the Andes of southern Peru.
Methona Doubleday, 1847 (Lepidoptera: Nymphalidae: Danainae) is a small genus of the tribe Ithomiini including seven species (Lamas 2004), distributed from Panama to northern Argentina, Uruguay, and southern Brazil (Neild 2008).
Methona confusa Butler, 1873, is distributed from Eastern Panama to the Amazon basin, with four weakly differentiated subspecies recognized (Lamas 2004). It is encountered commonly in a variety of forest habitats, from primary premontane cloud forest to lowland secondary growth (Neild 2008, Hill & Tipan 2008). In Peru, this species is widespread and common on the eastern slopes of the Andes below 1,500 m.
Materials and Methods
In September 2012, as a result of a butterfly survey in the upper montane area of the Megantoni National Sanctuary (MNS), on the eastern slopes of the Andes of southern Peru, one female specimen of M. confusa (Fig. 1) was collected near the boundary of MNS and the Manu National Park (MNP), Cuzco Department (12°30′25″S, 72°05′20″W), at 3,700 m elevation. The area is an ecotone between open, páramo-like vegetation (‘wet puna’) and elfin forest. The butterfly was flying at the summit of a small hill, sometimes falling into the ground vegetation and remaining there motionless, but before capture had been cruising “upand-over” the summit, being blown off the top by strong winds and flying against the wind in approaching summit. In addition, some 200 m downhill, two more individuals of this species were found, heavily damaged and dead on the ground; those individuals may have been killed by the heavy rains falling in the area during the previous days.
Material examined. One female: Peru, Cuzco, Incatambo, 12°30′30″S, 72°05′05″W , 3,700 m, 12-15 September 2012, J. Cerdeña, R. Delgado & E. Huamaní leg. The specimen is deposited in the Museo de Historia Natural, Universidad Nacional Mayor de San Marcos (MUSM), Lima, Peru.
This is the first Ithomiini species ever reported in a high Andean ecotone between wet puna and elfin forest, as ithomiines normally occur in humid forests from sea level to about 3,000 m (Willmott & Freitas 2006). Indeed, this event would have been less remarkable if a related species, Methona maxima nigerrima (Forbes), which has been recorded up to 2,950 m elevation at sites a few km to the south, in the upper Cosñipata valley (Lamas, unpubl. data), had been found in this particular location. This is also a new elevational record for this group, the highest ever reported for ithomiines.
The only reliable hostplant records for species of Methona belong to the genus Brunfelsia Linnaeus, 1753 (Solanaceae) (Lamas 1973, Plowman 1998, Beccaloni et al. 2008). Five species of Brunfelsia (amazonica C.V. Morton, 1949, chiricaspi Plowman, 1973, dwyeri D'Arcy, 1971, grandiflora D. Don, 1829, and pauciflora (Cham. & Schltdl.) Benth. in DC., 1846) have been reported as larval foodplants for M. confusa (Plowman 1998); of them, B. pauciflora is almost certainly misidentified as the species is endemic to southeastern Brazil, where M. confusa does not occur. Only B. grandiflora has been found in the general area where the M. confusa specimens discussed herein were recorded, thus it is highly possible that the latter fed as larvae on individuals of that species. Although B. grandiflora is often cultivated as an ornamental shrub or small tree (Plowman 1998), there is no evindence of its presence above 2,000 m in southeastern Peru (indeed, no species of Brunfelsia have been recorded as occurring above 3,300 m [Plowman 1998]). Furthermore, the area of the MNS where this survey was conducted has no human inhabitants or man-made roads. Therefore, it is reasonable to hypothesize that M. confusa has no resident breeding populations in the area surveyed and was not introduced there through human agency.
If the M. confusa adults reported here were not part of a resident, breeding population, they may have either been performing long-distance dispersal through unfavorable habitat (the wet puna / elfin forest ecotone) between two separate areas of “normal” habitat (montane forest), or else were exhibiting hilltopping behavior (Shields 1968). At least one species of Methona (singularis Staudinger, 1884) has been cited as exhibiting summit congregation behavior (Kesselring in Shields 1968), and it may occur in M. confusa too. Considering that in the same study site we recorded a skipper (Hesperiidae) specimen which was obviously engaged in hilltopping behavior, and turned out to represent a new country record for Peru (Cerdeña et al. 2014), this highlights the importance of surveying hill summit habitats in order to significantly increase the chances of registering the occurrence of scarce or otherwise elusive butterfly species while performing biodiversity surveys (see also Dolibaina et al. [2012, 2015] and Cerdeña & Farfán  for other remarkable findings made at hill summits).
To MBZ Fund Conservation by financing granted to the first author to carry the project titled “High Andean Butterflies of Biosphere Reserve Manu: Diversity, endemism and conservation.” Field work was performed under authorization R.J. Nº 0010–2012 SERNANP-SNM issued by the Servicio Nacional de Áreas Naturales Protegidas por el Estado (SERNANP), Ministerio del Ambiente, Peru.