Two new species of Baetodes Needham & Murphy, 1924 with an updated checklist of Baetidae (Ephemeroptera) of Rondônia state, Brazil.

Baetidae is one of the most taxon-rich families in the order Ephemeroptera, and the most studied mayfly in Brazil. Despite recent advances, the vast majority of the Brazilian territory has not yet had its diversity well documented. Some of these critical gaps are in the South-Western Amazon, with emphasis on the state of Rondônia due to the high level of environmental threat (especially deforestation).

New species and new records of Miroculis Edmunds, 1963 (Ephemeroptera: Leptophlebiidae) from Chacoan Domain in northeastern Brazil.

The genus Miroculis Edmunds, 1963 (Ephemeroptera: Leptophlebiidae) is endemic to South American with 27 described species. In Brazil, 21 of these are known to occur. The present paper describes three new species of Miroculis Edmunds, 1963.

New species and stages description of Traverella Edmunds, 1948 (Ephemeroptera: Leptophlebiidae) from Northeast Brazil.

The genus Traverella Edmunds, 1948 (Ephemeroptera: Leptophlebiidae) has 15 described species, three of them recorded from Brazil: Traverella bradleyi (Needham Murphy, 1924), T. insolita Nascimento Salles, 2013 and T. maranhensis Nascimento, Lima Azevedo, 2019.

The nymph of Hermanellopsis arsia Savage amp; Peters, 1983 (Ephemeroptera: Leptophlebiidae) from Brazilian Northeastern Region.

Hermanellopsis Demoulin, 1955 is a genus of Leptophlebiidae known from adults of both sexes and is represented solely by two species, both from South America: Hermanellopsis arsia Savage Peters, 1983, described only from male subimago; and H. incertans (Spieth, 1943) described from male imago and female subimago. Edmunds et al.

A new species of Traverella Edmunds, 1948 (Ephemeroptera: Leptophlebiidae) from Brazil.

A new species of Traverella Edmunds (Ephemeroptera: Leptophlebiidae) is described based on male imagoes from the state of Maranhão, northeastern Brazil. The main characteristics that distinguish the new species from the other species are: 1) subgenital plate forming two lateral, broad projections with two fine, long spines dorsally recurved; 2) penis lobe triangular and apically rounded, with a small ventral projection at apex and a ventral longspine slightly curved and directed to midline.

Description of the nymph of Thraulodes sternimaculatus Lima, Mariano amp; Pinheiro, 2013 (Leptophlebiidae: Ephemeroptera) from Northeastern Region of Brazil.

Thraulodes Ulmer, 1920 is one of the most abundant and widespread genera of Leptophlebiidae represented by 66 species (Barber-James et al. 2013; Gonçalves et al. 2013; Lima et al.

New species and new records of Coryphorus Peters, 1981 (Ephemeroptera: Coryphoridae) from Brazil.

A new species Coryphorus is presented,  based on recent collections from Northeastern Brazil and specimens deposited in the Museu Regional de Entomologia da Universidade Federal de Viçosa (UFVB) and Coleção Zoológica da Universidade Federal de Roraima (UFRR). Coryphorus molinerii sp. nov.