Susceptability of leafminers to insecticides 



JESO Volume 139, 2008 



TABLE I. LC 50 and level of resistance of 2 American serpentine leafminer strains (Ontario 

 = O; Susceptible = S) exposed to formulated insecticides, either registered (abamectin, 

 cyromazine) or reduced risk (chlorantraniliprole, spinosad), using a leaf dip bioassay. 



Insecticide 



Strain 



N 



Slope 



Pearson 



LC 1 



50 



95% 

 Fiducial 

 Limits 



Resistance 

 Ratio 



O/S 



Abamectin 







249 



1.52 



0.262 



1.05 



0.72- 1.40 



17.5 





S 



318 



1.94 



0.219 



0.06 



0.05 - 0.07 





Cyromazine 



O 



343 



1.40 



0.453 



33.6 



26.0 - 44.0 



10.2 





S 



220 



3.13 



0.087 



3.28 



2.24-4.41 





Chlorantraniliprole 







289 



1.99 



0.292 



0.63 



0.53-0.76 



3.0 





S 



295 



3.10 



0.169 



0.21 



0.19-0.24 





Spinosad 







192 



2.14 



0.673 



2.82 



2.01 -3.67 



2.8 





s 



177 



2.31 



0.121 



1.00 



0.81 - 1.28 





1 Concentrations expressed as ppm. 



TABLE 2. LC 95 for the Ontario American serpentine leafminer strain exposed to formulated 

 insecticides using a leaf dip bioassay compared to recommended application rates. 



Insecticide LC, 



95 % Fiducial Limits Recommended 

 Application Rates 



101-1051 141 



7.9-27.8 11 



2.0-26.5 24 



2.6-11.0 9 



Cyromazine 506 2 



Abamectin 12.7 



Spinosad 16.5 1 



Chlorantraniliprole 4.3 



Concentrations and rates are expressed as ppm. 



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