摘要：The development of insecticide resistance threatens the continuity of insect pests control,information availability for resistance levels in field populations has a great importance to realize insect pest status to avoid the negative effect of insecticides resistance and to minimize using more insecticides,which will be estimated by monitoring of field populations over time and locations.In this investigation,laboratory strain of medfly,Ceratitis capitata flies was exposed to a series of concentrations.The resistance percentages and enzymatic activity in field strains collected from different four locations in the delta valley in northern Egypt were also monitored.The results showed that the highest concentration (800 ppm) achieved 91.80±1.08 in laboratory strain while the lowest concentration (50 ppm) caused only 28.21±1.37%.Based on the resistance values in field strains,flies collected from the west location,exhibited the highest mortality rate with lowest resistance percentage however,flies collected from the east location showed the lowest mortality rate with highest resistance percentage.Strains collected from different fields recorded remarkable higher levels of the studied enzymatic activity i.e.acetyl cholinesterase AchE,alkaline phosphatase,P-esterases and mixed function oxidase than the baseline laboratory strain,positive correlation between resistance levels in the different strains and the enzymatic activity levels in these strains was detected.Data elucidates the consequences of insecticides abuse,which manifested in the increasing of insect pest resistance toward the action of the pesticide.
