Termidor SC can be shipped to California but it cannot be used for indoor applications. Since you have drywood termites in the attic, the most recommended product for your situation would be Bora-Care. Bora-Care is applied to raw wood for termite control and it will penetrate the entire piece of wood and erradicate an active infestation as well as preserve it. The great thing about Bora Care is that it is natural, last for the entire life of the wood (never goes away), and dries completely clear. Termidor would not be recommended because it doesn't penetrate wood and injections directly into the affected wood would be neccessary for treatment and it doesn't last very long.
Termidor SC is a applied with a pressure of 25 PSI or less
You can use Termidor SC twice a year at a rate of 0.8 oz (0.06% finished solution) per gallon of water or up to 4 times a year at a rate of 0.4 oz (0.03% finished solution) per gallon of water. If you decide to use it twice a year, you can apply it on a window of 4-6 months. If you decide to use it four times a year, you can apply it every 2 months starting in March/Spring.
Termidor SC and Timbor are used for two different purposes. Termidor SC is generally a ground treatment, while Timbor is used to treat wood directly. Mixing two insecticides together could potentially cause a resistance with pests. It would basically be like doubling up on a product, and that is unnecessary. Moreover, Termidor is only labeled for spot application to wood where there are active termite infestations; it cannot be broadcast over the wood and would not be absorbed into it the way Timbor will. It is recommended that you follow the label when using any professional products.
Termidor SC is not labeled to be used out in the yard. We would recommend to use Dominion 2L which can be applied to and around the stump. Be sure to treat around your home as well to prevent. Check out our Termite Guide for all the up to date tips on Termite prevention and control.
Termites do not normally attack live, healthy trees. If the tree has been damaged by termites it would be advisable to remove the tree and perform a liquid termite soil treatment. Most people are primarily concerned with protecting the big investment, their home, and Termidor SC? would be the product to use for that. Please take a moment to read over our article on "How to do a Termite Treatment" for complete details. In most cases, termites out in the yard are completely normal and can be left alone. Termidor is only labeled to be used adjacent to structures and when used as directed is safe around plants/trees that are in this area.
Yes, Termidor SC will work for Formosan termites. Formosan termites are a species of subterranean termites and Termidor SC is labeled for subterranean termites.