Population fluctuation of some different insect species of the genus Sitophilus (Coleoptera: Curculionidae) and their parasitoid, Anisopteromalus calandrae, (Howard) (Hymenoptera: Pteromalidae) were studied at El-Beheira Governorate (Egypt). The present results show that during the first year 2013 S. oryzae reached its peak in August where the average number was 510 adult per kilogram wheat. While S. granarius and S. zeamais reached its peak at December and September achieved 401 and 300 adults per kilogram grain, respectively. The parasitoid A. calandrae was active from March to November and reached its peak in August achieved 112 parasitoid per kilogram. The parasitoid sex ratios of A. calandrae increased gradually with increasing temperature and reached its peak in August of the year 2013 recorded 2.3 female to 1male. The duration of immature stages of the parasitoid A. calandrae decreased with increasing temperature where it was extended from 26.89 day at 20°C to 11.55 day at 35°C. The parasitoid total numbers also increased gradually with increasing temperature from 20°C to 30 °C, recorded 67.67 at 30 °C. Then, the numbers decreased also at 35 °C recorded 62.67. The results illustrated also that there were significant difference in sex ratio between the temperature of 20 °C and 35 °C. Where, at 20°C the sex ratio was 2 females:1male. Whilst, at 35 °C the sex ratio was 2.3 females:1male. No significant differences in the sex ratio were observed between the temperature of 20, 25 °C and 30 °C. From the previous results the temperature of 30 °C was the most desirable temperature for the activity of the parasitoid.
Keywords: Anisopteromalus Calandrae, Biological Parameter, Insect Hosts, Parasitoid, Population, Temperature
