A new Metalmark discovered in REGUA (Lepidoptera: Riodinidae)?

Unidentified metalmark species (© Alan Martin)
Unidentified metalmark species (© Alan Martin)

Rio de Janeiro is one of the best researched states in Brazil concerning the inventory of its flora and fauna, even so new taxa pop up from time to time and some groups, like the Arthropoda, or some areas are still poorly represented in state checklists.

Being a connoisseur in butterflies, around May 2010, Jorge spotted what seemed to be an unknown blackish metalmark of the genus Symmachia – remarkable among other characters by the ‘bent’ shape of its anterior forewing margin – when inspecting the saplings of the old REGUA nursery for butterfly caterpillars. Without a net and a camera at hand, the bug went unidentified with the hope of finding it soon again, given the notorious metalmark habit of coming back to the same spots at the same hours of the day, generation after generation.

Therefore, did it happen, on 25 March 2011 a Symmachia specimen was seen and netted while hill toping and perching near the lodge swimming pool. This time it was photographed indoors. Investigation is still going on, but its identity has been established as related to Symmachia probetor (Stoll, 1782), a remarkable range extension for what is usually taken as a central American/Amazonian species, not only seems to be new for REGUA, the Três Picos State Park area or Rio de Janeiro State itself, but for the whole south and eastern part of Brazil. The question if it might be an undescribed subspecies or the nominotypical race is still being addressed and investigated. A visit to the Museu Nacional (UFRJ) collection is scheduled to inspect the Symmachia holdings and check the records from the available label data.

Findings like this, more than exciting, highlight the faintness of our knowledge of tropical faunas, even in the best or historically sampled territories. Novelty can be lurking in places not as far as remote Amazonian areas, the Congolese forests or the Papuan mountains, the difference being on the speed at which what is left of this rich Biodiversity near human settlements is vanishing before it can even be registered. This remarkable record was found about a two hour drive from the second largest Brazilian metropolis and main tourist hub, and is a showcase on the importance of the conservation work carried out by the REGUA project.