THERMAL REQUIREMENTS AND ESTIMATIVE OF NUMBER OF GENERATIONS OF SPALANGIA ENDIUS WALKER, 1839 (HYMENOPTERA, PTEROMALIDAE) IN PELOTAS, RS, BRAZIL

ABSTRACT The aim of this work was to estimate the thermal requirements and the number of generations, monthly and annually, of Spalangia endius in pupae of Musca domestica at four constant temperatures. The development period of S. endius was obtained through 100 pupae of M. domestica, with ages between 24-48 hours, exposed for 24 hour to the parasitoids for each temperature, with three replicas. After this period the pupae were individualized in assay tubes and placed in B.O.D. with temperatures of 20, 25, 30 and 35º C and humidity ≥ 70% and photophase (12h), where they were observed daily until the emergence of the parasitoids. The temperature influenced the duration of the development period of S. endius. The shorter period form egg to adult was at 35º C (16.84 days) and the higher percentage of emergence was at 20º C (37%). The basis temperature was 11.27ºC with a thermal constant of 390.96 degrees-day (DD). The development period was inversely proportional to temperature and the medium of generations per year was 7.24, varying from 7.03 to 7.48.