الفهرس 
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Abstract
Microbial insecticides are essentially nontoxic. They also do not pose a disease risk to wildlife, humans, and other organisms not closely related to the target insect. In fact, they can be applied when a fruit or vegetable is almost ready for harvest. Most microbial insecticides are toxic to a single species or group of insects, so you can often target a pest without the risk of killing beneficial insects in the process. Also, most microbial insecticides can be used in conjunction with conventional insecticides. The performed experiments have given promising results can be summarized as follow:
1- Six antibiotics were used to determine the opposite genetic markers in Bacillus strains to be used in conjugation process.
2- All Bacillus strains were sensitive to chloramiphinicol, erythromycin and cefradine. Bacillus thuringiensis (Bt) and Bacillus megaterium (Bm) strains were sensitive to amoxicillin but B. licheniformis (Bl) and Bacillus subtilis (Bs) strains were resistant. Also, Bl, Bm and Bs strains were sensitive to tetracycline but Bt strain was resistant. Bt and Bl strains were sensitive to ampicillin but Bm and Bs strains were resistant.
3- Six heavy metals were tested against Bacillus strains appeared that all strains were sensitive to Cu, Zn and Co except Bt strain was tolerant to Co.
4- All strains were tolerant to Pb and Mn except Bt strain was sensitive. However, Bt and Bm strains were sensitive to Ni but Bl and Bs strains were tolerant.
5- All matings done in this study between Bacillus thuringiensis (Bt) strain and three strains of Bacillus; Bacillus licheniformis (Bl), Bacillus megaterium (Bm) and Bacillus subtilis (Bs) were succeeded.
6- Most of transconjugants produced higher units of chitinase and proteinase more than their parental strains. However, both transconjugants; Tl2 and Tl4 resulted from the mating between Bt and Bl strains produced higher units of chitinase than other isolates.
7- Two transconjugants; Ts3 and Ts5 resulted from the mating between Bt and Bs strains were more effective in proteinase production than the other isolates.
8- The following transconjugants; Tl4, Ts5 and Tm4 gave the highest larvicidal activity if compared to other bacterial insecticides against 2 nd instar larvae of cotton leafworm S. littoralis after seven days of treatment. The LC50 values were 9.69x106, 7.93x106 and 8.76x106 spores/ml, respectively. The percent change of effectiveness compared to Bt as the reference strain were 17.60, 32.57 and 25.51% for Tl4, Ts5 and Tm4, respectively.
9- Recombinant bioinsecticides; TL2, Ts5 and Tm4 gave the highest larvicidal activity if compared with other bioinsecticides against 2nd instar larvae of cotton leafworm after nine days of treatment. The LC50 values were 6.87x106, 6.06x106 and 6.68x106 spores/ml, respectively. The changes in effectiveness percentages compared to Bt as the reference strain were 17.72, 27.43 and 20.00% for Tl2, Ts5 and Tm4, respectively.
10- Transconjugants; Tl2, Ts5 and Tm2 were more toxic against 4th instar larvae of cotton leafworm after seven and nine days of treatment if compared with other bacterial insecticides. The LC50 values after seven days were 16.65x106, 14.69x106 and 14.17x106 spores/ml, respectively, but after nine days were 10.6 x106 , 9.8 x 106 and 9.54 x 106 spores/ml.
11- The changes in effectiveness percentages compared to Bt as the reference strain were 16.54, 26.37 and 28.97% for Tl2, Ts5 and Tm2, respectively against 4th instar larvae of cotton leafworm after seven days, but after nine days of treatment were equal 23.19, 29.00 and 15.21%, respectively.
12- The medium lethal time (LT50) to recombinant bioinsecticides number Tl2, Tl4, Ts5 and Tm4 against 2nd instar larvae of cotton leafworm with high concentration of spores (20 x 106 spores/ml ) were 3.93, 3.81, 3.52 and 4.13 days, respectively.
13- The LT50 to recombinant bioinsecticides number Tl2, Ts5 and Tm2 were 6.00, 5.21 and 5.46 days, respectively against 4th instar larvae of cotton leafworm with high concentration of spores (20 x 106 spores/ml).
14- Mortality percentage was 83.5 % when used Tl2 against 2nd instar larvae of cotton leafworm after seven days of treatment but it was reached to 59.3 % in the case of 4th instar larvae after the same time. However, mortality percentage was equal 70.1 % when Bt was used against 2nd instar larvae of cotton leafworm after seven days of treatment but it was reached to 48.9 % when Bt was used against 4th instar larvae after the same time.
15- Mortality percentage after three days of treatment was 40% when used Ts5 against 2nd instar larvae of cotton leafworm but it was reached to 82.5% after seven days of treatment against the same larval instar. However, mortality percentage was 27.7% after three days of treatment when Bt against 2nd instar larvae of cotton leafworm, but it was reached to 70.1% after seven days of treatment against the same larval instar.
16- Recombinant bioinsecticides were more efficacy than their parental strains against 2nd and 4th instar larvae of cotton leafworm (field strain) with high spores concentration (20 x 106 spores/ml). Also, transconjugants number Tl2, Ts5 and Tm4 were more effect if compared with other recombinant insecticides.
17- Mortality percentages to 2nd instar larvae of cotton leafworm after three days of treatment were reached to 51.74%, 58.64% and 55.19%, but to 4th instar larvae it were reached to 44.58%, 51.48% and 48.29%, for initial effect of recombinant bioinsecticides; Tl2, Ts5 and Tm4. However, initial effect of Bt bioinsecticide caused mortality percentage to 2nd instar larvae was reached to 37.59% and it was reached to 31.06% to 4th instar larvae after three days of treatment.
18- Recombinant bioinsecticides were more toxic against cotton aphid than their parental strains especially transconjugant isolates number Tl2 and Tl4 resulted from the mating between Bt & Bl also Tm2 and Tm4 resulted from the mating between Bt & Bm. The LC50 values of these transconjugants were 16.9 x 106, 19.4 x 106, 19.8x106 and 17.9x106 viable spores/ ml, respectively after two days of treatment in laboratory experiment.
19- Toxicity was also increased after four days more than that at two days from treatment against cotton aphid A. gossypii, where the LC50 values after four days were 8.6x106, 9.4x106, 10.3x106 and 9.3x106 viable spores/ml with transconjugants; Tl2, Tl4, Tm2 and Tm4, respectively.
20- Three recombinant bioinsecticides; Tl2, Ts5 and Tm2 caused the highest reduction in population percentages to cotton jassid E. lybica in field experiment. They were reached to 85.09%, 82.86% and 73.21%, respectively after five days of treatment in the field experiment.
21- Recombinant bioinsecticides; Tl4, Ts5 and Tm4 recorded highest reduction in population percentages to cotton aphid A. gossypii which reached to 78.95%, 79.56% and 66.75%, respectively after five days of treatment in the field experiment.
22- Bt strain caused reduction percentage reached to 35.19 % of jassid insect population and 64.30% of cotton aphid insect population in field experiment on cotton crop.
23- All bacterial insecticides were tolerant to Diafenthiuron (Polo500 50%SC), Chlorfenapyr (Challenger 36%SC) and Alpha-Cypermethrin (Pistox 15% EC). whereas, it had a low effect against Chlorpyrifos (Dursban 48% EC) under the field concentration of chemical insecticides.