In the humid forests around Manaus, along the banks of the Mogi Guaçu River in São Paulo, and across the vast Pantanal wetlands, eight tiny moths once dismissed as a single species are now recognized as distinct inhabitants of Brazil's most biodiverse regions. These brownish insects, each measuring barely two centimeters from wing tip to wing tip, tell a story about how science sees the living world—and how that vision is being reframed through an explicitly anti-colonial lens.
What was classified in 1818 as Eois russearia turned out to be something far more complex. For centuries, researchers looked at these moths and saw one species. But when scientists at the State University of Campinas and the University of São Paulo brought together molecular analysis, careful examination of female genital morphology, and records of which plants the caterpillars eat, the truth emerged: there are at least eight distinct Brazilian species hiding within that single name.
The breakthrough required more than just advanced technology. Simeão de Souza Moraes, the coordinator of the study published in Scientific Reports, emphasizes that "integrating different techniques is important in species description—state-of-the-art methods are welcome, but not necessarily enough." The researchers examined COI gene sequences, compared the minute variations in wing patterns and reproductive structures, and tracked which Piper plants each population preferred as food. This combination revealed what morphology alone could not.
But perhaps the most striking aspect of this discovery lies in how the scientists chose to honor it. Seven of the new species were named after Orixás—foundational deities of Candomblé and Umbanda, central religions in Afro-Brazilian culture. Two species, Eois iemanja and E. ibeji, inhabit the Atlantic Forest-Cerrado transition zone near Mogi Guaçu in São Paulo. E. nanan and E. iogunede are found in the Pantanal wetlands of Mato Grosso do Sul. E. oxumare, E. orumila, and E. iroco live on the outskirts of Manaus in the Amazon. An eighth species, E. stantonae, honors Mariana Alves Stanton, a USP researcher who died in 2024 while contributing to the study.
"The process of choosing names has an anti-colonial and anti-imperialist nature," Moraes notes, directly countering the historical practice of naming Neotropical organisms after Greek and Roman gods—a naming convention that reflects the dominance of European scientific traditions. By grounding these new species names in indigenous Brazilian culture, the researchers are reshaping whose knowledge and whose world views are embedded in scientific nomenclature itself.
The ecological significance extends beyond nomenclature. These moths interact with plants of the Piper genus in ways that may yield biotechnological applications through the uptake of secondary compounds—natural molecules with untapped potential. Moreover, this work illuminates just how much biodiversity remains hidden in plain sight. A 2020 study from Moraes's group suggested the Eois genus itself may contain up to 176% more species than previously documented. Gene sequences already hint at three additional species in this complex, though researchers haven't yet examined them morphologically.
For Brazil's scientific community and beyond, these eight moths represent something larger: a moment when rigorous, cutting-edge biology joins forces with a deliberate reckoning about whose voices and whose cultures deserve to shape the living world's catalog.