Thesis (Ph.D.) - Cairo University - Institute of African Research and Studies - Department of Natural Resources

Developing appropriate control methods for the desert locust Schistocerca gregaria has become increasingly important due to the severe damaging effect of this pest. In the present work, the effectiveness of the entomopathogenic fungus Metarhizium anisopliae var acridum against 5th nymphal instar of S. gregaria was estimated. Percentage mortality of the nymphs was estimated by the lethal time (LT), using different fungal concentrations and the higher measured LT₅₀ was 7.81 at the concentration of (107 spores/ml/nymph). Also, LC₅₀ (6.3{u00D7}10⁵spores/ml/ nymph) was calculated. Significant prolongation of duration of 5th nymphal instar S. gregaria was recorded, when infected with M. anisopliae (10⁴, 10⁶ spores/ml/nymph, 2.3, 1.5 folds respectively) and Lactose (0.6, 0.2 mM/ml, 1.6 fold) alone, and Aspirin combined with the fungus (1.7 fold), compared to control. 100% malformation of the nymphs was observed post treatment with the combination of garlic oil and the fungus, while it was 24% post garlic oil treatment alone and 4% post treatment with Aspirin and different fungus concentrations alone. All the nymphs treated with garlic oil and the fungus failed to moult (100%), but the percent of the unsuccessful moulting was 12% post treatment with Aspirin solely or in combination with fungus and the fungus (10⁷ spores/ml/nymph) alone, 8% post treatment with fungus (10⁴ spores/ml/nymph) alone, and 4% post treatment with garlic oil and the fungus (106 spores/ml/nymph) alone. Pla

Issued also as CD