The biology of Scymnus (Pullus) argentinicus Weise on Schizaphis graminum at the temperatures 20, 25 and 30ºC was studied. The temperatures of 25 and 30ºC were favorable to S. (Pullus) argentinicus development. The average of the incubation period was 3.24 days and the larval development was 8.43 days at 25ºC. The duration of the instars and pre-pupal and pupal periods was significantly shorter at 25 and 30ºC. The percentage of emerging adults was higher at 30ºC (98%) while at 20ºC this percentual was 82%.
