fluctuation continued at a moderate level until the mid of May and then started to increase until it reached to three peaks from the mid of June to the mid of Augustwhen the temperature degrees were at 29 -27.5 °C.A. schlechtendalioccur on the unders

Narmen A. Youssef and Atef A. Abd-ELgayed

Abstract

The insecticidal activity of three commercial Bt – formulations and one fungus; namely DipelDf , W- Bus and Protecto (Bacillus thuringiensis var.kurstaki ) and Biofly ( Beauveria bassiana) were tested against 2nd and 4th instar larvae of Spodoptera littoralis (Boisd) and Hypera brunneipennis (Boheman) were studied under laboratory conditions. Results revealed that Bt- formulations caused the larval mortality after treatment of S. littoralis 2nd and 4th larval instars ranged from 40 to 100 % and 32.5 to 92.5 % and reached 100 ,85 and 100 % for H. brunneipennis, respectively at the highest concentration after 7 days of treatment compared to 77.5 % and 60 % for S. littoralis and 95 and 85 % for H. brunneipennis treatments by Biofly. The DipelDf and W-Bus were highly efficient on the insect larvae, followed by Biofly and Protecto, respectively. Based on the LC50 values, DipelDf was the highest toxic to S. littoralis and H. brunneipennis than that of the other compounds. Pupation and adults emergence percentages were reduced by all treatments compared to control.

Key words

Spodoptera littoralis ,Hypera brunneippennis, commercial products , efficiency