I'm using "drc" package to analyze a data set from a larval package test.

The test include two tick species and one known suceptible strain used as reference.

The question is:

- Is there a command in package "drc" that computes RR (e.g. RR50) of a species comparatively to the reference strain ?

-If so, which one? if not, how can I do that? another package ?

Sincerely