ABSRTRACTTreated The second larval instar by residual method indicated that, chlorpyrifos-methyl and methomyl formulations expect Goldben (90.48 % mortality) caused 100 % mortality, while the lowest mortality percent occurred in emamectin benzoate and lufenuron formulations.Except Broact formulation0, there are significant differences between all the tested formulations (ranged from 0.00 to 64.29 % pupation and to 53.57 % adult emergence) and untreated control in pupation (85.71 %) and adult emergence (78.57 %) On the contrary, there are no significant differences between two formulations of each active ingredient except two formulations of emamectin benzoate in pupation percentage only. Treated The second larval instar by feeding method indicated that,chlorpyrifos-methyl formulations is the highly toxic (100 % mortality), when methomyl, emamectin benzoate and lufenuron formulations were low toxic (ranged from 3.70 to 27.27 % mortality) and lufenurononly was high toxic by ingested than leaf residual exposure.. Also, there are highly significant differences between chlorpyrifos-methyl formulations (0.00 % for pupation and adult emergence) with other treatments (ranged from 60.71 to 78.57 % for pupation and from 57.14 to 71.43 % for adult emergence). Treated egg by dipping method showed a significant reduction in hatchability rates for formulations of methomyl and chlorpyrifosmethyl ranged from 65.05% (Goldben) to 76.69% (Reldan), however, there are no significant reductions in hatchability rates for formulations of emamectin benzoate and lufenuron, ranged from 86.08% (Broact) to 95.88% (Match) compared to the control (98.33%), but there are not significant differences between two formulations of each active ingredient.

To induce cypermethrin resistance in Culex pipiens larvae, about 20000 4 th instar larvae of Cx. pipiens were collected from Assiut field and exposed to cypermethrin selection pressure for fifteen generations using dipping method. This study revealed that the resistance ratio (RR50) of the parent strain (G0) was 14.49-fold as compared with susceptible strain. This RR50 value increased gradually from each generation to the next one as a result of selection pressure with cypermethrin. The regression line for cypermethrin against the parent field strain showed slope value 2.38 which indicate a moderate level of heterogeneity of parent strain to cypermethrin. The first five generations during the course of cypermethrin selection showed that resistance ratio (RR50) was increased gradually from one generation to the next (The RR50 increased from 14.49-fold in G0 to 135.40-fold resistance in G5). By the 6 th generation, the rate of resistance development to cypermethrin was fairly rapid where; the RR50 to cypermethrin increased from 135.40-fold in G6 to 272.00-fold resistance in G11. With the beginning of the 12 th generation, the development of resistance to cypermethrin was increased very slowly during the last four generations from 279.92-fold in G12 to 295.52-fold resistance in G15 (plateau phase). Finally, the slope values were volatile until the eleventh generation (2.38 -3.63) and then relatively proven in the last four generations (4.55 -4.52). This is evidence of increasing homogeneity of selected strain in the last five generations.

Field experiments were carried out at Mutobus District, Kafr El-Sheikh Governorate to evaluate the efficacy of Ackocynil R (bromoxynil octanoate 32.75% EC) at 1.00 L. fed-1 , Brominal W R (bromoxynil octanoate 24% EC) at 1.00 L. fed-1 , Derby R (florasulam 7.5 %+ flumetsulam 10%) at 30 ml fed .-1 , Icopart R (pyraflufen-ethyl 2% SC) at 250 ml fed.-1 and Sinal R (metosulam 10% SC) at 40 ml fed.-1 in comparison with handweeding twice (at 21 and 42) days after sowing and untreated check (weed free) during 2017/2018 and 2018/2019 seasons on broad-leaved weeds in wheat crop. Anagallis arvensis, Beta vulgaris, Cichorium pumpilum, Medicago sativa, Rumex dentatus and Sanchus oleraceus, were the predominant weed species during the both seasons, except, Anagallis arvensis, which was found in the second season only. All predominant weeds in the experimental field were identified as broadleaved weeds. Among predominant weed species, Beta vulgaris and Medicago sativa were the most predominant during 2017/2018 and 2018/2019 seasons. Results clearly indicated that all herbicidal treatments showed significant herbicidal activity against weeds compared to the control during the two examined seasons. Among the herbicides examined, Ackocynil R and Brominal W R were the most options in controlling weeds as well as increasing yield components and grain yield in wheat crop than the other treatments.