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Abstract. The spatial variation in the abundance of individuals may be associated with the variation in environmental variables. The productivity hypothesis proposes that climate affects plant productivity, which may limit the abundance of beetles. The thermal‐limitation hypothesis proposes the direct effect of ambient temperature may limit beetle abundance. We analysed the abundance of epigaeic beetles at the Subantarctic–Patagonian transition to test for these abundance–environment relationships. We collected beetles using 450 pitfall traps within a ~150 × 150 km area representative of the Subantarctic–Patagonian transition. We used path analysis to evaluate the relationships between beetle abundance and plant cover, litter biomass, averaged minimum and daily temperature range, and mean annual precipitation. We used principal coordinates of neighbour matrices to model the spatial autocorrelation of the data. The abundance of beetles increased strongly with tree canopy cover and less strongly with herb cover. The increase in shrub cover had a positive effect on beetle abundance in areas to the east of the transition, within the scrubland‐steppe, but it has a negative effect on beetle abundance in areas to the west of the transition, within the forests. The association between beetle abundance and minimum daily temperature was negative or weak throughout. Increased temperature variation had a negative effect on beetle abundance. We suggest that indirect positive climatic effects mediated through plant cover are important to account for the variation in beetle abundance, which favours the productivity hypothesis. Thermal limitation may operate locally through variation in daily temperature range.

Forest sites in Northwestern Argentinean Patagonia were surveyed to determine the oribatid mite fauna. A taxonomic inventory of oribatid mites was carried out in Northwestern Argentinean Patagonia to establish the taxonomic diversity, for increasing the knowledge of their distribution, detecting new species and assessing environmental effects on the oribatid mite community. Eleven sampling sites in nearly pure forests of Austrocedrus chilensis, Nothofagus dombeyi, Nothofagus antarctica were selected as these are among the most recurrent arboreal species found in this region. Samples of leaf litter, soil and pitfall traps contents were taken from each forest. Fifty-five oribatid species, belonging to 46 genera in 28 families, were found. Nine species are new records for Argentina and one for continental Argentina. Thirty-two species were recorded in A. chilensis forests, 35 in N. dombeyi forests and 20 in N. antarctica forests. Fifty species were found in leaf litter, 35 in soil and eight in pitfall traps. Fourteen species were recorded exclusively in leaf litter, one in soil and four in pitfall traps. A high level of endemism is confirmed as nearly 62 % of collected species have previously been found only in Southern Andes supporting the existence of an associated autochthonous oribatid fauna.

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Son caracterizadas las myiasis registradas en Bariloche y establecidas las condiciones probables bajo las cuales se produjeron las infestaciones. Las larvas obtenidas a partir de heces de 2 pacientes fueron identificadas como Eristalis tenax (Diptera: Syrphidae) de acuerdo a las claves de Hartley (1961) y Organización Panamericana de la Salud (1962). Estos 2 casos de myiasis gastrointestinal humana constituyen los primeros registrados en Bariloche (Patagonia, Argentina) y sus características responden a las registradas para esta especie de Díptera en otras partes del mundo. La falta de control específico en el sistema domiciliario de suministro de agua ha sido la causa más probable de la infestación. Este registro extiende la distribución de E. tenax y de las myiasis gastrointestinales humanas en América del Sur hasta los 41º 03' S.