In the last decades, the loss and reduction of wetlands have become evident worldwide due to various pressures related to the increase in human population and their activities. This situation is also present in the coastal wetlands of Peru, especially in small bodies, which makes it necessary to investigate their biodiversity and ecology in order to provide useful information for management and conservation plans for these environments. The objective of this study was to describe the biodiversity and spatial composition of the aquatic macroinvertebrate community of the Huacho-Hualmay-Carquín coastal wetland. Collection was carried out in August 2018 at fifteen sites, divided into five sectors, recording the pH, electrical conductivity, salinity, total dissolved solids, and dissolved oxygen of each station. A total of 3 550 macroinvertebrates were collected, distributed in 67 genera, with a predominance of the orders Diptera, Coleoptera, and Hemiptera, which are widely cited as dominant groups in coastal lentic environments. This small wetland showed lower water electrical conductivity values compared to values reported in other Peruvian coastal wetlands; furthermore, it exhibited greater genus richness, especially in less impacted areas with considerable depth and high dissolved oxygen values, making it a diverse and important ecosystem within the large Peruvian coastal corridor.

The Salinas de Chilca are located at km 65 of the Panamericana Sur highway, represented by three lagoons: La Milagrosa (mainlagoon and salt ponds), La Mellicera and La Encantada. The environment of these lagoons belongs to the Subtropical Desert(d-ST) life zone. The objective of the present study was to determine the influence of environmental variables on changes in themacroinvertebrate community structure in the Salinas de Chilca, Lima, Peru. Four collection campaigns were carried out from Januaryto September 2018, establishing twelve sampling stations, three stations for each lentic environment. The sample was collectedthrough sweeps with a 500 μm mesh opening type D network on the shore of each lagoon. The physicochemical parameters of thewater presented different values in each lagoon and formed a descending salinity gradient from the saline pools (with hypersalinevalues) towards the La Encantada lagoon (with mesosaline values). 42 genera of macroinvertebrates were collected, with the mostinfluential genera in community patterns: Heleobia, Larsia, Trichocorixa, Ephydra and Artemia, these organisms represented 83.85 %of the total abundance. The environmental gradient generated by salinity determined two very different groups, a group of speciesthat do not tolerate high salinity values (mesosaline lagoons) from another group of species that support extreme salinity values(hypersaline lagoons); however, predation, anthropic alterations, habitat structure, among other factors, would also be influencingchanges in the community structure.

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.

Los estudios sobre macroinvertebrados acuáticos en ríos de gran altitud en los Andes son escasos, y se conoce poco sobre el papel trófico que cumplen estos organismos en estos ecosistemas. En el presente trabajo se estudia la preferencia de microhábitat de la comunidad de macroinvertebrados acuáticos y se describen sus gremios tróficos a través del análisis de contenidos estomacales en dos ríos altoandinos de Perú. Se encontraron diferencias significativas (p < 0.05) entre la abundancia, riqueza, índice de equidad de Pielou y número efectivo de especies entre los microhábitats estudiados en ambos ríos. Los mayores valores de riqueza en ambos ríos fueron encontrados en el microhábitat piedra mediana, siendo los más abundantes y diversos los miembros del orden Diptera. Los menores valores de riqueza se encontraron en el microhábitat roca. Se identificaron cuatro ítems alimenticios: materia orgánica particulada fina (MOPF), microalgas (MA), restos animales (RA) y tejido vegetal (TV), de los cuales la MOPF fue el que predominó en casi todos los organismos analizados, lo cual demuestra que la MOPF es el principal ítem alimenticio consumido en ambos ríos. Espacialmente fueron los detritívoros y herbívoros los que estuvieron en gran proporción en casi todos los microhábitats en ambos ríos altoandinos.

Coastal wetlands are ecosystems that are being reduced every day due to anthropic factors. In these environments, taxonomic and ecological studies are scarce, especially in the Neotropical zone. The lack of biological monitoring in these areas has prevented the gathering of evidence on a probable loss of aquatic biodiversity. In the present study, we present the first taxonomic list of aquatic Diptera larvae from two wetlands of the central coast of Perú. Additionally, we describe the breeding of pupae and the emergence of Ephydridae (Diptera) adults in the laboratory. The sites with the presence of Ephydridae pupae were characterized by shallow waters with a muddy substrate and low vegetation; only Ephydra gracilis pupae were found in shallow pools with no vegetation, floating or embedded in salt crusts. The success of ephedrid flies breeding was 53% as the development of fungi and the emergence of parasitoid Hymenoptera reduced the emergence success of some of the genera. Adult emergence success from Ephydra gracilis was lower than that of others, probably due to the lack of some physicochemical condition only found in its natural habitat. We present a first taxonomic listing of aquatic Diptera for two coastal wetlands, the first record of Ephydra gracilis (Packard, 1871) in South America, and illustrations of the pupae supporting its identification. We also give recommendations for the collection and care of early stages of Diptera flies in the laboratory.