The present studies were carried out at Plant Protection Research Institute, Sharkia branch, ARC to study toxic and biological effects of some bacterial isolates; Pseudomonas plecoglossicida, Bacillus endoradicis and Bacillus pumilus which isolated from the contaminated artificial diet, dead pupae of Helicoverpa armigera (Hunber) by washing and grinding, respectively against the newly hatched larvae of H. armigera and Earias insulana (Boisd.). Results showed that all bacterial isolates had toxic effect on the newly hatched larvae of the two insects. Increasing the concentration of each bacteria caused a gradual increase in mortality percentage of the newly hatched larvae of american and spiny bollworms. The newly hatched larvae mortality percentages increased as the days post- treatment increased for the same bacterial isolates. P. plecoglossicida had the highest mortality percentage (70.25 & 79.25%) and (68.25 & 77.00%) of the newly hatched larvae of american and spiny bollworms after two and four days from treatment, while the lowest mortality percentage were (39.00 & 61.00%) and (59.5 & 67.00%) recorded with B. endoradicis, respectively.  These isolates cleared the different effects on all stages of american and spiny bollworm and decreasing pupal weight, pupation & adult emergence percentages, male and female longevity, deposited eggs and hatchability percentages as compared with control. Each strain identified and characterized by Biolog system