New species and records of the Neotropical genus Cyrnellus (Trichoptera: Polycentropodidae) and the re-establishment of C. minimus and C. marginalis.

Cyrnellus is a small genus of Polycentropodidae distributed in the Nearctic and Neotropical regions, absent from the Chilean subregion. Two new species are here described: C. boliviensis sp.

The genera Smicridea McLachlan and Chimarra Stephens in French Guiana (Trichoptera: Hydropsychidae, Philopotamidae).

A brief collecting exploration to small streams in the coastal zone of French Guiana resulted in the capture of eight species belonging to the genus Smicridea McLachlan 1871 and two belonging to the genus Chimarra Stephens 1829. Given the scarcity of knowledge about the trichopteran fauna of this territory, the results of the study of this material are provided. A new species of the genus Smicridea is described: Smicridea (Rhyacophylax) sanctorum sp.

Transfer of mercury and methylmercury along macroinvertebrate food chains in a floodplain lake of the Beni River, Bolivian Amazonia.

We have evaluated the mercury and methylmercury transfers to and within the macroinvertebrate communities of a floodplain lake of the Beni River basin, Bolivia, during three hydrological seasons and in two habitats (open water and vegetation belt). Using the stable isotopes delta(13)C and delta(15)N, six trophic chains were identified during a previous study. Four are based on only one source: seston, organic matter from the bottom sediment, periphyton and macrophytes.