Tanya told me that I need to apply Essentria every two weeks. But I forgot to ask if it gets washed away with the rain and needs to be reapplied, or if it is sticky enough that I can stick to the two week plan even if it rains.
Yes, Essentria will need to be applied after it rains for best results. Since thiere is very little residual effectiveness, it works primarily by repelling insects. Rain will dilute it to the point where it is no longer effective.