Finney (1944) describes a toxicity trial of five different
concentrations of pyrethrins (percent) plus a control that were
administered to eggs of Ephestia kuhniella.
The natural mortality rate is large, and a common adjustment
is to use Abbott's formula.
References
Finney, D. J., 1944.
The application of the probit method to toxicity test
data adjusted for mortality in the controls.
Annals of Applied Biology, 31, 68--74.
Abbott, W. S. (1925).
A method of computing the effectiveness of an insecticide.
Journal of Economic Entomology, 18, 265--7.