Doses are established for both the Bottle Bioassay and the Larval Bioassay
the same way.
Assays are run on susceptible mosquitoes with a series of insecticide
concentrations.
The data are plotted, creating a line graph similar to that in Figure
1. Convert the absolute mortality numbers to percents so that you
will have consistent graphs that can be compared more easily.
Up to a point, the higher the concentration of insecticide used in an
assay, the shorter length of time it takes for the insects to die. There
is a concentration at or above which mosquitoes die at a maximal rate.
The lowest dosage at which this occurs is the optimal diagnostic dosage.
This dosage should be used in all further assays with that particular
insecticide and mosquito species.
Figure
1
Conclusion:
The diagnostic dosage is the most useful dosage for detecting resistance.
A dose that is too low will result in false detection of resistance.
A dose that is too high will conceal resistance at some level.
