Depending on how heavy the rain was will depend on if you will need to reapply. If the rain was only light and you had just completed a Termidor treatment in a trench for termite prevention then you should be fine. If it was a heavy rain for a long period of time then you may need to reapply. If you were using the Termidor to spray around the perimeter of your home for ants and general insects, then you will likely need to reapply it on a day when no rain is expected for at least 24 hours.
Per manufacturer, the most effective termite treatment would be digging the 6in x 6in trench around the foundation and applying Termidor SC per label. If the gap is close to the suggested trench requirements, we do not see where this would not be as effective.
Termidor SC can only be applied around the foundation of your home or other building structure for control of ants and other listed insects. You cannot use the product out on or around the trees or fences because it is not labeled for this type of application. We recommend using our most popular product for spider mites, Talstar P. Talstar P is known to have a pretty good miticide effect for these plant-infesting pests. When Talstar P is over-used the mites are known to build up a resistance to the active ingredient. The other choices would be to use a Horticultural Oil or an insecticidal soap. Both of these products work best when they make direct contact with the pest and both products are known to cause discoloration to spruce trees. The pro to using one of these products is that spider mites cannot build up a resistance to them.