Bioassay of the Bacteria Bacillus thuringiensis kurstaki in Ephestiacautella on Dates

Abstract

Aim: This study was conducted to evaluate the efficiency of the bacteria Bacillus thuringiensiskurstaki in the eggs, second instar larvae ,fourth instar larvae and adults Of the insect Ephestiacautella, Methods: Three concentrations (1g,2 g and 4g/L) of Bioinsecticide bacterial B.thuringiensiskurstaki were prepared by mixing each one of these concentrations with a liter of distilled water. Results: The results showed that the highest mortality rate of bacterial was (23.53%) during the seventh day of the concentration (4 g / L) and the lowest mortality rate was (0.00%) during the third day of the concentration (1 g / L) of the eggs. (93.5%) during the seventh day of the concentration (4 g / L) and the lowest mortality rate was(8.89%) during the first day of the concentration (1 g / L)of the second instar larvae . The results showed that the highest mortality rate was (85.56%) during the seventh day of concentration (4 g /L ) And the lowest mortality rate was (6.67%) during the first day of the concentration (1 g /L) of the fourth instare larvae , while the adult mortality rate was highest (87.18%) during the fifth day and (100%) during the sixth and seventh day of the concentration (4 g / L) and the lowest mortality rate (11.11%) during the first day of concentration (1 g /L). Conclusion: the present study concluded that the Effect of bacteria on the adults and second instar larvae better than the effect of bacteria on fourth instar larvae and egg.