We report the first known infestation of mangroves by the invasive moth Hyblaea puera in Paraná, Southern Brazil. The infestation caused massive defoliation of Avicennia HIGHLIGHTS• We report the first known infestation by Hyblaea puera in mangroves of Paraná, Southern Brazil.• Massive defoliation of Avicennia schaueriana was observed in a large portion of local mangroves.• We visually estimated levels of impact, focusing on protected areas.• Insert a highlight no longer than 85 characters.2 Faraco, L.F.D.; et al.