The relation of the temperature of the water with the distribution of the present species in the area was studied.. The observations were made in three sections of the Lluta River, where they registered the temperature to 7:00 A.M. and 7:00 P.M. and collected larvae and pupae in natural substrates like stones and submerged vegetation, coming later to its taxonomic identification. The collected data were analyzed statistically using the coefficient of correlation of Pearson between the average temperature of the water and the amount of individuals collected of each species. The obtained correlations were in S. escomeli of r = 0.774, S. philippii of r = -0.442 and S. quechuanum r = -0.142. During the period of observation S. lescomeli presented intense positive correlation with respect to the temperature of the water.

Se estudió la relación de la temperatura del agua con la distribución de las especies presentes en el área. Las observaciones fueron realizadas en tres secciones del río Lluta, donde se registraron las temperaturas a las 7.00 AM y 7.00 PM y se colectaron larvas y pupas en sustratos naturales como piedras y vegetación sumergida, procediendo posteriormente a su identificación taxonómica. Los datos obtenidos se analizaron estadísticamente utilizando el coeficiente de correlación de Pearson entre la temperatura media del agua y la cantidad de individuos colectados de cada especie. Las correlaciones obtenidas fueron en S. escomeli de r = 0,774, S. philippii de r = -0,442 y S. quechuanum r = -0,142. Durante el período de observación la especie S. escomeli presentó una correlación positiva intensa respecto a la temperatura del agua.

The female and male of Dasybasis (Agelanius) cortesi, new species, is described and illustrated from specimens collected in the National Reserve of Río Clarillo, Cordillera Province, Central Chile. Its relationships to other Dasybasis species are discussed.