Who is Andesiops peruvianus (Ulmer, 1920) (Ephemeroptera: Baetidae)? New insight from the type basin using morphological and molecular analyses.

Andesiops peruvianus (Ulmer, 1920) is a small minnow mayfly with a distribution throughout the Andes Mountains, mainly in lotic environments. In recent years, the taxonomic status of the species has been shifting, even finding out molecular and morphological evidence to consider it as a cryptic species. In this work, we collected seven specimens of A. peruvianus from the Lake Titicaca in Peru, the type locality and perform molecular and morphological analyses to test their relationship with specimens from other regions. The species delimitation analysis revealed the existence of five MOTUs for specimens identified as A. peruvianus along the Andes Mountains, while the Lake Titicaca specimens formed a single MOTU with high interspecific distance. In this MOTU were found specimens with different types of abdominal gills, from translucent to markedly tracheated supporting the hypothesis of phenotypic plasticity at the abdominal gill level. Also, an extension in the range of tarsal claw denticles, from 10-12 to 10-14, were observed, higher than what were found in other regions. Our results support A. peruvianus as a species complex and reveal A. peruvianus from Titicaca as a single MOTU. Future morphological revisions of topotype specimens as well as from other Andean regions are required to strengthen the diagnosis of informative characteristics at both the larval and adult stage to elucidate the real status of the species.

The imago of Baetodes traverae Mayo, 1972 (Ephemeroptera: Baetidae), with a redescription of the nymph.

Male imago of Baetodes traverae is described and its nymph is redescribed. The male imago is distinguished from the other known species of the genus by (1) abdominal tubercles absent, (2) turbinate eyes moderately large and not contiguous apically, (3) segment II of forceps without constriction, (4) coxal gills absent, and (5) abdominal tubercles absent. Baetodes traverae nymph is redescribed, with new illustrations aiming to improve the original description done by Mayo (1972). Its nymph has the following characters: (1) terminal filament very short, less than half the length of abdominal segment X, (2) labium with glossae very short, less than half the length of paraglossae, (3) labrum expanded laterally, with submarginal row of four setae, (4) coxal gills absent and (5) abdominal tubercles absent.

Clave taxonómica de ninfas de Ephemeroptera(Insecta) del sudeste de Perú / Taxonomic key of nymphs of Ephemeroptera (Insecta) from southeastern Peru

Ephemeroptera es un orden de insectos cuyas etapas inmaduras cumplen un importante papel ecológico en los ecosistemas acuáticos. Sin embargo, el conocimiento de su diversidad en áreas tropicales aún es escaso. Específicamente, en el Perú se han reportado 64 especies pertenecientes a 35 géneros y ocho familias. En este estudio se presenta una clave taxonómica para la determinación de géneros de ninfas de Ephemeroptera de la vertiente suroriental de los Andes del Perú. Las ninfas revisadas fueron recolectadas en las quebradas de los departamentos de Cusco y Madre de Dios, dentro de un gradiente altitudinal de 180 - 4411 m, en los años 2012, 2013, 2015 y 2017. Se utilizaron tres metodologías de muestreo: recolección manual, red Surber y colonización de paquetes de hojas. Se reconocieron 48 géneros de ocho familias en 36 quebradas dentro de este gradiente. Seis géneros son nuevos registros para el Perú: Prebaetodes, Zelusia, Meridialaris, Tricorythopsis, Homoeoneuria y Hubbardipes.

Ephemeroptera is an insect order of whose immature stages play an important ecological role in aquatic ecosystems. However, its diversity knowledge in tropical areas is scarce. In particular, only 64 species of 35 genera and eight families have been reported in Peru. In this work, we provide a general key of Ephemeroptera nymphs for southeastern Peru. Nymphs were collected from streams of Cusco and Madre de Dios departments, within an altitudinal gradient of 180 - 4411 m, in 2012, 2013, 2015 and 2017 years. The samples were obtained by manual collection, using a Surber net and by colonization of leaf packs. We recognized 48 genera within eight families, coming from 36 streams within the gradient. Six genera are new records to Peru: Prebaetodes, Zelusia, Meridialaris, Tricorythopsis, Homoeoneuria and Hubbardipes.