Effect of the bioinsecticide Bacillus thuringiensis kurstaki on the biological aspects of cotton leafworm, Spodoptera littoralis (Boisd.) [electronic resource].

Includes references.

The experiments were conducted to evaluate the effect of different concentrations of Bacillus thurlngiensis kurstaki (Dipel 2X) on the 4th Instar larvae of Spodoptera littoralis (Boisd.). The highest percent of mortality of the 4th Instar larvae was achieved at the concentrations of 4000 and 2000 ppm after 96 hrs of treatment. While, the least mortality percentages were recorded with the other concentrations (250, 500, 1000). The pupation percentage was gradually reduced to the minimum rate with the highest concentrations (2000, 4000ppm). Results also cleared that there was a gradual significant decrease In adult emergence process, as the concentration increased (P=0.0002). Slight significant difference (P= 0.034) in the larval period was observed after treating 4th instar larvae at the highest concentration (2000, 4000) compared to the control. Significant differences (P= 0.0001) were noticed In pupal duration between the control and all tested treatments except the lowest concentration (250ppm). The pupal weight significantly differed among the all treatments Including the untreated control (P=O.OO01). There was a wide and significant variation In the fecundity of S. littoralis among different treatments (P=0.0001). Number of laid eggs /female reduced as the concentration Increased. On the other hand, the egg hatchability was reduced significantly (P=0.0004) in all tested treatments compared to the control. The experimental results proved that this blopesticlde, (Dlpel 2x) could be used as an alternate control method In combating the pest and implicated In the Integrated Pest Management (IPM). Key words: Spodoptera littoralis, Bacillus thurlngiensis, bioinsecticide, biological aspects.

Summary in Arabic.

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