The Cowpea aphid, Aphis craccivora (Koch), is considered a serious insect attacking several crops. Aphis craccivora has developed resistance to various insecticides. Resistance monitoring in Dakahlia, Qalubia and Bani-Suef field strains were studied. Results showed that the field strain from Dakahlia field strain was resistant to the tested organophosphates, carbamates and neonicotinoids. However, the Bani-Suef field strain exhibited lower levels of resistance. Esterase activity in the three field strains was generally high as the activity ratio ranged between 4.3-7.8, whereas, the activity of both glutathione -s- transferase (GST) and mixed function oxidases (MFO) were moderate in Qalubia and Dakahlia field strains. Therefore, biochemical and molecular studies were carried out to elucidate the mechanisms of resistance in the cowpea aphid to primicarb and thiamethoxam. The thiamethoxam resistant strain showed 48-fold resistance after selection pressure with thiamethoxam for 12 generations. The strain exhibited cross resistance to pirimicarb and carbosulfan and vigor tolerance to malathion and acetamiprid. DEF increased thiamethoxam toxicity to the thiamethoxam resistant strain (ThR) 5.58 times. Biochemical assays revealed that carboxylesterase (CbE) activity was 30 times higher in the ThR strain. AChE activity was 3.68 times higher in R-strain compared to S-strain. Pirimicarb resistant strain showed 47-fold resistance after selection pressure for 12 generations. This strain also exhibited remarkable cross-resistance to carbosulfan, malathion, chlorpyrifos methyl and thiamethoxam. Vigor tolerance levels to fenitrothion and acetamiprid were also found. DEF was a remarkable synergist which showed significant CbE activity. PBO had a synergistic effect by inhibiting MFO activity, and GST had a little role in conferring resistance in PR-strain. AChE enzyme activity in pirimicarb resistant strain (PR) was 2.77-fold compared to the susceptible strain. The I50 ratios of PR-strain to S-strain were 9.11 and 12.4-fold as determined by eserine and pirimicarb, respectively. Real-time PCR showed that the transcription level of Ace2 mRNA in PR-strain was 3.44 fold higher than that in susceptible stain. Three Site-directed mutagenesis are presented G60A, S72R and Q123P in Real-time PCR products. This clarifies that mechanism of resistance in PR-strain referred to metabolic and insensitivity of AChE.

The current study was carried out in order to monitor theresidue levels of chlorinated pesticides in drains water from Kalubia and Dakahlia Governorates. The results showed thatthe residue level of Gamma-HCHin Kalubia drains was higher than the other isomers (alpha and beta HCH) in all samples. Chlorothalonil was detected in Kafr-Abed, p,p,DDE eas higher than p,p,-DDD and p,p,-DDT in all water samples. In Dakahlia drains Gamma-HCH was higher than alpha and beta HCH. An exception was noticed in beta-HCH residues from Dondate drains. Dieldrin showed that highest residue level in selica being 12.77 ppb. Herbicide residues in the drains under investigation showed that all were contaminated with Dithiopyr at variable levels. Bensulfuron-methyl was not detected in any drains from the samples collected in the two governorates. Also the role of the water-hyacinth plant in the removal of some serious heavy metals from the water system was noticeable. Data clearly showed that water in Marioteia drain was contaminated with contained a higher concentration of lead than the Mansoureia canal in Giza governorate, but cadmium and copper concentrations were lower in it. Lead and copper levels were found to be higher in water-hyacinth than in spinach and lettuce in both Marioteia and Mansoureia locations. While cadmium levels were less in this plant than in the other two vegetable plants in the same two locations. These data indicated that water-hyacinth accumulates more heavy meals from the water system than any other crop. It removes some serious heavy metals and cleans the water.

This work has been carried out to investigate a novel synthesis of pyrido -1,2-a-benzimidazole, benzimidazolo -2,1-a-isoquinoline, benzimidazolo -1,2-a-napthyrid-inthione, heteroylazopyrido -1,2-a-benzimidazole, pyrazolo -4, 5 : 2, 3- pyriodo -1, 6 -a- benzimidazole, azepino -1,2-a- benzimidazole, pyrrolo-1,2-a-benzimidazole, B-styrenylcrotononitriles, benzimidazole-2 -ylaniline, 4-thiazolidin-on-2-yl-pyrrolo-1,2-a-benzimidazole, derivatives and utility of these compounds as insecticides agents.