Abstract:

This study determined the differences in development time, survival, and fecundity of Euseius finlandicus (Oudemans) (Acari: Phytoseiidae) when feeding on Tetranychus urticae (Koch) (Acari: Tetranychidae) together with birch pollen at 16, 20, 25, and 30 ± 1 °C, 65 ± 10% RH, and 16:8 photoperiod under laboratory conditions. Total development times for E. finlandicus were 29.48, 18.15, 7.28, and 5.90 days for females and 28.16, 17.54, 7.03, and 5.81 days for males at 16, 20, 25, and 30 ± 1 °C, respectively. Total egg production was highest (30.53 eggs) at 25 °C, whereas daily egg production was highest (1.80 eggs) at 30 °C. Female longevity was 74.39, 58.93, 28.05, and 16.67 days at 16, 20, 25, and 30 ± 1 °C, respectively. The development threshold for eggs and egg to adult stages were 13.78 °C and 13.22 °C for females and 13.72 °C and 13.10 °C for males, respectively. Females and males required 95.24 and 94.34 degree-days, respectively, to became adult. Euseius finlandicus had the highest intrinsic rate of increase (rm), 0.220 females/female/day at 30 °C, followed by 0.165 females/female/day at 25 °C, 0.064 females/female/day at 20 °C, and 0.033 females/female/day at 16 °C.

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