Based on collections in three coast Brazilian states, Hydrosmilodon plagatus sp. nov. and Needhamella mazama sp. nov. are described based on nymphs and adults. Besides the description of these species, new geographic records of the Hermanella complex are presented. The species included are: Hermanella maculipennis (Ulmer, 1920); Hermanella froehlichi Ferreira and Domínguez (1992); Hydrosmilodon gilliesae Thomas & Péru (2004); Hy lister plaummani Domínguez and Flowers (1989); Leentvaaria palpalis Demoulin (1966); and Needhamella ehrhadti (Ulmer, 1920). In addition, in this work Leentvaaria palpalis is recorded from Brazil for the first time.

The imago stages of three species of the Hermanella complex are described mostly based on material from Roraima, northern Brazil: Hydrosmilodon gilliesae, Hydromastodon sallesi and Leentvaaria palpalis. Male imagos of Hydrosmilodon gilliesae and Leentvaaria palpalis both have a pair of large, broad projections at the posterior margin of the styliger plate, nearly covering the penis lobes; in L. palpalis, however, these projections are fused. The male imago of Hydromastodon sallesi resembles Hydrosmilodon plagatus in that both species have a styliger plate with a robust projection that is curved towards the penis lobes. DNA barcoding is likely to be a powerful investigative tool for identifying and understanding species limits among these Ephemeroptera taxa, especially if it is used within an integrative taxonomic context. An updated identification key to the genera of the Hermanella complex is proposed. The imago stages of three species of the Hermanella complex are described mostly based on material from Roraima, northern Brazil: Hydrosmilodon gilliesae, Hydromastodon sallesi and Leentvaaria palpalis. Male imagos of Hydrosmilodon gilliesae and Leentvaaria palpalis both have a pair of large, broad projections at the posterior margin of the styliger plate, nearly covering the penis lobes; in L. palpalis, however, these projections are fused. The male imago of Hydromastodon sallesi resembles Hydrosmilodon plagatus in that both species have a styliger plate with a robust projection that is curved towards the penis lobes. DNA barcoding is likely to be a powerful investigative tool for identifying and understanding species limits among these Ephemeroptera taxa, especially if it is used within an integrative taxonomic context. An updated identification key to the genera of the Hermanella complex is proposed.

In the present study we used larval amphibians (Rhinella jimi) as prey, and beetle larvae (Hydrophilus sp.) as predator to assess if increased water temperature influences predator-prey dynamics. The experiment was carried out in replicated aquatic microcosms with two different water temperatures (control and a ‘warming water’ scenario). Survival of tadpoles decreased significantly in the treatment compared to the control and at the end of the experiment, all tadpoles in the ‘warming water’ scenario had been ingested, unlike in the control treatment, where only half of the tadpoles were ingested. Our results demonstrate that the alterations in abiotic conditions (water temperature) can reshape predator-prey dynamics in a future scenario of global warming. The consequent increase of predation may intensify negative effects on population size in anuran larvae. Although changes are likely, they are complex and often counterintuitive.

New species for Thraulodes Ulmer, 1920 (Ephemeroptera: Leptophlebiidae: Atalophlebiinae) and the first key to adults from Brazil