Abstract
The effects of the aphid parasitoid Diaeretiella rapae (M'Intosh), the predator Coccinella undecimpunctata L. and the entomopathogenic fungus Beauveria bassiana (Bals.) on the cabbage aphid Brevicoryne brassicae L. were evaluated in this study. The effects of host densities on D. rapae parasitizing B. brassicae were studied at five densities of the parasitoid (2, 4, 8, 12 and 16 females). The highest percentages of parasitism were 92.6, 57.6 and 47% for D. rapae at 16 parasitoids/200 aphids in the field, pots and Petri-dishes in lab, respectively. The developmental time of predator C. undecimpunctata larvae instars was 14.8 days. The average number of aphids consumed during the C. undecimpunctata larva stage was 442.45 individuals of B. brassicae. The adult male consumed a total average 5073.83 of B. brassicae individuals while, the female consumed 6615 of B. brassicae individuals. Three tested concentrations (10 5 , 10 6 and 10 7 spores/ml) of B. bassiana formulations were used against aphid B. brassicae. Mortality percentage after 7 days of application showed 35.55, 46.66 and 64.44%, respectively. The obtained results revealed that LC50 was 1.1×10 6 spores/ml and LC90 was 3.4×10 9 spores/ml. According to these results, D. rapae, C. undecimpunctata and B. bassiana
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