The Amazon rainforest is the world’s most extensive tropical rainforest, holding a considerable ecological and taxonomic diversity. Speciation in this region arises from multiple factors, such as topography, climate fluctuations, oceanic transgression, vegetation and the delimitation of zones circumscribed by sub-basins within the greater Amazon basin. Different scenarios have been proposed to better understand the diversification of Amazonian taxa, whether by Pleistocene refugia or by areas of endemism.                The genus Scaria is distributed mostly in Amazonia, with a single species that ranges from the Tumbes-Chocó-Magdalena ecoregion well into Central America all the way to southern Nicaragua. Eight species are currently recognized, with three additional described here as new: Scaria rafaeli sp. nov., S. jonasi sp. nov. and S. granti sp. nov., and the status of S. laeta stat. resurr. is revalidated. Two new combinations are established: S. verutum comb. nov. (formerly placed in Rehnidium Grant, 1956) and Batrachidea brevis comb. nov. (formerly placed in Scaria). New synonym is proposed: Batrachidea brevis (Hancock, 1909) = Batrachidea inermis Hebard, 1923 syn. nov. Lectotypes and paralectotypes were selected for S. laeta, S. maculata and S. lineata, as well as the neotypes for S. hamata and S. boliviana. An updated key to species of Scaria is also provided.                A cladistic analysis for 15 species was performed (12 in the inner group and 3 in the outer group) with 40 morphological characters, confirming the monophyly of Scaria. A biogeographical analysis of dispersion-vicariance indicates that the origin of the genus was probably in the Inambari endemism center as the only reconstruction of the resulting ancestral distribution, five dispersions and three vicariance events being postulated. These suggest that both types of events are equally important in the current configuration of the distribution in Scaria. Vicariance events arise mostly by isolation of the species because of the uplift of the Andes and the dispersion events comprise four waves originating from the ancestral range into central and east Amazonia.

The status of the genus Phelene stat. resurr., previously synonymized under Chiriquia is revalidated. The genus is redescribed and Phelene turgida stat. rev. a lectotype and paralectotypes are designated for this species. Tetrix laticeps is proposed as nomen dubium and its described a new additional species Phelene maroon n. sp. The diagnosis of the subfamily is adjusted with the characters of the new taxa included and an updated key of genera and species is provided.

Identification Orphulellini grasshoppers (Acrididae: Gomphocerinae) species has been difficult due to high polymorphism rate. Orphulella Giglio-Tos, 1894 is a genus with widespread geographical distribution and poor descriptions. Orphulella punctata (De Geer, 1773) has an extensive record of occurrence and available information about the phallic complex, however, there is poor data describing other parts of the male reproductive tract. The objective of this study was characterizes the internal organs of the male reproductive system and spermatozoa of O. punctata. Orphulella punctata testes are of Fountain type, each having only four follicles. Spermatozoa into the seminal vesicle are arranged in bundles with c.a. 2320 µm length, with a nucleus 110 µm long. The spermatozoa are covered by a glycocalyx, the nucleus is cylindrical with condensed chromatin and connected to the flagellum by a dense and lamellar centriole adjunct. The axoneme have 9 + 9 + 2 pattern and present two symmetrical mitochondrial derivatives. A fibrous net and two flat membranous cisternae fill the space between the axoneme and mitochondrial derivatives. This is the first description of the reproductive system of a Gomphocerinae representative.

A new species of the genus Oecanthus Serville, 1831 from Reserva Natural Vale, state of Espírito Santo, Brazil is described. The new species differs from other of this genus in characteristics of the pseudepiphallus main lobe, endophallic sclerites, posterior median lobe of the metanotal gland and black spots on the femora and tibiae. The chromosome number is 2n=16+XY♂=18 and 2n=16+XX♀=18, and this complement present one pair of autosomes less than the other five cytological studied species.

The Batrachideinae subfamily is a well-defined and taxonomically stable taxon, with a pantropical distribution and an important representation in the Neotropical region. In this study, the characters and distributions of the genera and species are discussed based on a morphological analysis and a key to genera of the American Batrachideinae is also provided. New synonymies are established: Tettigidea Scudder, 1862 = Eotetrix Gorochov, 2012 syn. nov.; Batrachidea mucronata (Saint-Fargeau & Serville, 1825) = Tettigidea granulosa Bruner, 1913 syn. nov.; Batrachidea planus (Hancock, 1907) = Batrachidea brevis (Hancock, 1909) syn. nov.; Tettigidea lateralis (Say, 1824) = Tettigidea nicaraguae Bruner, 1895 syn. nov.; Tettigidea lateralis (Say, 1824) = Tettigidea annulipes Bruner, 1910 syn. nov.; Tettigidea cuspidata Scudder, 1875 = Tettigidea corrugata Bruner, 1910 syn. nov.; Tettigidea cuspidata Scudder, 1875 = Tettigidea multicostata Bolívar, 1887 syn. nov.; Tettigidea chapadensis Bruner, 1910 = Tettigidea costalis Bruner, 1910 syn. nov.; Tettigidea chapadensis Bruner, 1910 = Tettigidea hancocki Bruner, 1910 syn. nov.; Tettigidea intermedia Bruner, 1910 = Tettigidea subatera Bruner, 1910 syn. nov.; Tettigidea scudderi Bolívar, 1887 = Tettigidea steinbachi Bruner, 1920 syn. nov. Three species are transferred from the genus Tettigidea to the genus Paxilla Bolívar, 1887: Paxilla mexicana (Hancock, 1915) comb. nov., Paxilla tecta (Morse, 1900) comb. nov., Paxilla nigra (Morse, 1900) comb. nov.; Tettigidea unicornis (Gorochov, 2012) comb. nov. is transferred from the genus Eotetrix Gorochov, 2012 to Tettigidea, and Batrachidea planus (Hancock, 1907) comb. nov. from Tettigidea to Batrachidea Serville, 1838. Five new species groups (lateralis, armata, cuspidata, paratecta and scudderi) are recognized in the genus Tettigidea. Neotype of Tettigidea lateralis lateralis is designated. Keys to the Batrachideinae genera and species of the most diverse American genera (Tettigidea and Paxilla) are also provided.