Water quality information is essential supporting decision making in water management processes. The lack of information restricts, at some point, the implementation of adequate sanitation, which is still scarce in developing countries. In this study, an ecosystemic water quality assessment was conducted in the Virilla river in Costa Rica, in a section of particular interest for future sanitation development. It included the monitoring of physical, chemical, microbiological and benthic macroinvertebrate parameters from 2014 to 2016. Mutivariate statistics and water quality indexes were used for data interpretation. Results indicated that water quality decreased downstream towards more urbanised areas. Particularly, extreme values of phosphorous, nitrogen and E. coli were found. Sample sites were grouped in two clusters, which were consistent with land use. Benthic macroinverterbrates diversity was predominantly represented by Baetidae, Chironomidae, Leptohyphidae, Hydropsychidae, Simuliidae and Physidae. They were mostly influenced by water temperature, nitrite, ammonium, soluble reactive phosphorous, total solids, alkalinity, nitrate and total suspended solids. Three water quality indexes consistently showed the poor condition of the water body. The overall results indicate that the main sources of pollution in the river are likely to be wastewater discharges. Thus, special efforts should be undertaken regarding its regulation in the country.

The nymph of Cloeodes dantasp. nov. is described from male and female nymphs collected from highland streams in the Caribbean Slope of the Costa Rica Central Volcanic Mountain Range. Adults are unknown. In addition, C. excogitatus and C. redactus are recorded for the first time in the country. Cloeodes dantasp. nov. can be differentiated from all described species by the predominantly brownish coloration on females and a similar coloration on males but with segments VII–IX light yellow and light brown, with no conspicuous marks or patterns; abundant scale-bases throughout most parts of the body; hindwings pads absent; the presence of three spines in the corners of the posterior margin of sternum III, and the posterior margin of tergum III with 28–30 spines on each side of the middle line (spine with a base width up to 0.5× spine length).