The State of Maranhão, located in northeastern Brazil, has a great biodiversity due to the complex of biomes that constitutes its territory. Due to the paucity of research in the area, there are gaps in knowledge of the local fauna. This work aims to contribute to the knowledge of the order Ephemeroptera. Two species of Baetidae, Callibaetis nigracyclus (Cruz et al. J Nat Hist 48:591–660, 2014) and Cloeodes auwe (Salles et al. Biota Neotrop 4:1–8, 2004a), and one species of Leptophlebiidae, Hermanella mazama (Nascimento, Mariano and Salles, 2012) are here registered from the State. It is noteworthy that the genus Cloeodes Traver 1938 and Hermanella Needham and Murphy (Lloyd Entomol Ser 24:1–79, 1924), still do not have records from the State and it is also worth mentioning that all new records represent an important geographic extension.

马拉尼昂州位于巴西东北部，由于其领土上生物群落复杂，因此拥有丰富的生物多样性。由于该地区研究匮乏，对当地动物群的了解存在空白。这项工作旨在为蜉蝣目的知识做出贡献。两种Baetidae，Callibaetis nigracyclus（Cruz et al. J Nat Hist 48:591–660, 2014）和Cloeodes auwe（Salles et al. Biota Neotrop 4:1–8, 2004a），以及一种Leptophlebiidae，Hermanella mazama（Nascimento、Mariano 和 Salles，2012）在这里是从国家注册的。值得注意的是，Cloeodes Traver 1938 和Hermanella Needham 和 Murphy (Lloyd Entomol Ser 24:1–79, 1924) 仍然没有来自国家的记录，还值得一提的是，所有新记录都代表了重要的地理延伸。