Drywood termites are all contained in a piece of wood. They do not go back to the ground like subterranean termites. For Termidor to work on drywood termites, you have to drill directly into the piece of wood the termites are in and inject Termidor into the wood. Termidor does not penetrate into wood, so you have to inject it into the center. It has to touch the termites to work, but the benefit is that it only has to contact a few termites, and then they can pass it on to the rest of the colony. To treat for subterranean termites using Termidor, you will need to trench all around the skirt just like you would around a home's foundation, and then you will need to trench around all of the blocks that are holding the trailer up, just like you would a home's piers in a crawlspace.
Termidor SC does need to be applied directly to soil. If you have concrete up against the foundation around the home you would need to drive every 10-12 inches through it and inject/spray ½ gallon into every hole as outlined in our Prevention guide here
If concrete such as a carport slab or sidewalk is against the foundation in the area where you need to treat, you will be required to drill through the concrete to apply the termiticide solution to the soil. Using the hammer drill with a 1/2" x 18" concrete drill bit, drill holes every 12" into the concrete along the foundation wall.
You are not only drilling through just the concrete here, but also as deep as you can into the dirt. The deeper the better. Once the holes are drilled, you fill at the same rate you did the trench, 4 gallons per 10 feet. If you drilled the holes 12 inches apart, then you would have 10 holes over 10 feet that you are trying to fill with 4 gallons. This works out to be a little less than half a gallon per hole. To fill these I would recommend using the one gallon sprayer on a "pin stream" setting so you can force the liquid down the hole and not splash it everywhere. You can also use a funnel and pour the termiticide down the holes. It is difficult to get 4 gallons per 10 feet in the holes, so it is important that you use a long drill bit, at least 18" long so you can bore out enough dirt to hold the termiticide. Sometimes the ground is slow to soak up the termiticide you place in the holes. You may need to fill the holes, then go work on something else for an hour, come back and fill them again, go work on something else... 3 to 4 times to get the proper amount down the holes. Once the holes are filled all you need to do is patch them with a concrete patch filler you can buy at a home improvement or hardware store or you can use our Trebor plugs that will close the hole with no concrete mess.
Termidor SC is not labeled for use on any bearing fruit trees. We would not recommend eating any fruit grown on the treated trees for at least 1 year.
Termidor SC when applied to wood would only last about 90 days and would not be used as pre-treatment for wood.
Bora-Care is usually the preferred choice for pre-treating wood that is exposed and it is raw wood you are treating, meaning it is not painted, stained, or sealed, it is just normal wood. Bora-Care is made only for wood. Bora-Care is sprayed evenly over all exposed surfaces of the wood and actually penetrates through the entire piece of wood. For frame up, you would apply to the bottom 2 feet of wood.
We also have a great article here about Barrier and Soil Treatments for termites that might be helpful.
Termites do not normally attack live, healthy trees so you most likely will not find any products that will work as a ground barrier around the trees. Most people are primarily concerned with protecting the big investment, their home, and Termidor SCwould be the product to use for that. It is only labeled to be used adjacent to the structure though. Please take a moment to read over our article on "How to do a Termite Treatment" for complete details.
