Termidor SC will treat spiders but you would only be able to use the product outside. Termidor SC does not have an immediate knockdown but instead uses a delayed reaction kill which makes it especially effective for social insects like ants, termites and certain species of wasps. Most folks will use a residual product with a broader application area. Please check out our spider control kit for a better option.
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.
If kept out of heat and sunlight the shelf life of Termidor SC is 3-5 years.
We reached out to the manufacturer BASF for an official answer on this verbiage on the Termidor SC label. Here is what they stated.
“Not using termiticides in voids with Rigid foam insulation” is EPA required language that dates back to times when soil termiticides contained organic solvents/adjuvants which helped them remain in solution long enough to be applied but also damaged rigid foam insulation (think DDT, Heptachlor, Chlordane, or Dursban times; e.g. Pre-Termidor products from the 1950’s through 1990’s). In 1996, the EPA mandated that the language be on all liquid termiticide labels moving forward (regardless of whether the product contained solvents or emulsifiers or not). Termidor products do not contain any caustic emulsifiers or solvents that would damage/ “eat up” the rigid foam board (as the 80WG, SC, HE lines are all water soluble).”
This also applies to the generic equivalent on the market under the branding Taurus SC. If you are needing to foam into the foundation void area where there is foam rigid board, they recommend using the Termidor Foam Aerosol as this labeling does not have that verbiage and restriction on it for use.
Termidor SC bonds to the soil and does not move once it is applied. Therefore, it can be applied where a well or garden is present as long as it is more than 10 feet away from the well or garden or tree. We would suggest not applying Termidor SC along the side of the house that is within 10 feet of the trees. You should keep a close eye on this area of the house for termites, or you can of course always install some Termite Bait Stations in that area for monitoring activity.