To treat subterranean termites we always recommend to trench where you can and also treat the crawlspace. Termidor SC can be used in crawlspaces. There are complete instructions on the Termidor SC product label (page 5) on how to use the product in the crawlspace, so if a bit inadvertently goes into the crawlspace it should not pose a problem.
Termidor SC should only be applied outside within 1 foot of a house or other structure. You also should not apply Termidor SC near edible plants. We would recommend to keep Termidor applications at least 10 feet from the garden.
One 20 oz. bottle of Termidor SC will cover 60 linear feet of trenching.
Termidor SC is not known to leech through the soil. You will need to follow the Termidor SC product label which has specific instructions for treating near a well to avoid any contamination issues:
TREATMENT AROUND WELLS OR CISTERNS: Do not contaminate wells or cisterns.
Structures With Wells/Cisterns Inside Foundations: Structures that contain wells or cisterns within the foundation of a structure can only be treated using the following techniques:
1. Do not apply within 5 feet of any well or cistern by rodding and/or trenching or by the backfill method. Treat soil between 5 and 10 feet from the well or cistern by the backfill method only. Treatment of soil adjacent to water pipes within 3 feet of grade should only be done by the backfill method.
a) Trench and remove soil to be treated onto heavy plastic sheeting or similar material or into a wheelbarrow.
b) Treat the soil at the rate of 4 gallons of solution per 10 linear feet per foot of depth of the trench, or 1 gallon per 1.0 cubic feet of soil. Mix thoroughly into the soil taking care to contain the liquid and prevent runoff or spillage.
c) After the treated soil has absorbed the solution, replace the soil into the trench.
Structures With Adjacent Wells/Cisterns and/or Other Water Bodies: Applicators must inspect all structures with nearby water sources such as wells, cisterns, surface ponds, streams, and other bodies of water and evaluate, at a minimum, the treatment recommendations listed below prior to making an application.
1. Prior to treatment, if feasible, expose the water pipes) coming from the well to the structure, if the pipes) enter the structure within 3 feet of grade.
2. Prior to treatment applicators are advised to take precautions to limit the risk of applying the termiticide into subsurface drains that could empty into any bodies of water. These precautions include evaluating whether application of the termiticide to the top of the footer may result in contamination of the subsurface drain. Factors such as depth to the drain system and soil type and degree of compaction should be taken into account in determining the depth of treatment.
3. When appropriate (i.e., on the water side of the structure), the treated backfill technique (described above) can also be used to minimize off-site movement of termiticide.
Typically what would be done is that you would have your regular 6 in x 6 in trench with your 4 gallons of Termidor SC solution per 10 linear feet, and then rod down to the grade (but not below) at each footer, or in the case of a continuous basement, about every 12 inches. You also can treat from the inside by drilling in the basement to treat the ground underneath it and any hollow block near the floor there.
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.
Fuse Termiticide and Termidor SC are both very good products. They both contain non-repellents so that the pests do not know they are coming in contact with it. Fuse does have two active ingredients, one of them being fipronil, which is in Termidor SC. The other is imidacloprid. Both act in the insects nervous systems, but in different locations. Imidacloprid targets post-synaptic nicotinic acetylcholine receptors in insects, causing over-stimulation of the insects nervous systems. Fipronil acts as a post-synaptic gamma-aminobutyric acid (GABA) inhibitor, also resulting in over-stimulation of the insects' nervous systems. According to the manufacturer, this product could last up to 8 years in the soil. Termidor SC lasts approximately 10 years in the soil. You will treat the same way with both products as well. FUSE is more labeled for wood infesting ants, such as carpenter ants whereas Termidor is labeled for a wider range of ants, acrobat, Argentine, big-headed, carpenter, crazy, odorous, pavement, pharaoh, thief.
Since Termidor SC is a non repellent, overmixing could negatively effect the treatment. We recommend to either add more water or start over using the recommended rate of 0.8 oz per gallon of water.