Subterranean termites — Reticulitermes flavipes mostly, with some Reticulitermes virginicus — are active across central Texas every month of the year. They don’t stop in winter; they slow. Spring swarms (March through May) are when most homeowners discover infestations because the alates are visible. By then, the colony has been feeding on something for years.

Austin’s termite pressure is high because the soil profile suits them: clay-loam over limestone, with year-round soil moisture in most yards thanks to irrigation. Older neighborhoods (Tarrytown, Hyde Park, Allandale, Old West Austin) have additional exposure from wood-frame construction, pier-and-beam foundations, and decades of cumulative soil contact.

The two real treatment options

Despite what the industry website copy says, there are two effective subterranean termite treatments. Everything else is either marketing or a variant of these.

1. Liquid termiticide soil treatment. A trenched-and-treated chemical barrier around the foundation, typically with non-repellent products (fipronil — Termidor — or chlorantraniliprole — Altriset). Properly installed, this is highly effective and lasts 8–10 years. The barrier kills foraging workers, who carry the active ingredient back to the colony via grooming and trophallaxis. Cost: $1,200–$2,800 depending on linear footage and foundation type.

2. Bait stations (Sentricon). In-ground stations placed every 8–10 feet around the home perimeter, monitored quarterly. When termites hit a station, the cellulose bait is replaced with a hexaflumuron or noviflumuron bait that kills the colony via inhibition of chitin synthesis. Sentricon (the brand) is the dominant system and requires Certified Specialist installation. Cost: $1,500–$3,000 install + $250–$400/year monitoring.

For most Austin homes, either works. The decision usually comes down to: (a) is the foundation type accessible for trenching, (b) do you have landscaping you don’t want disturbed, and (c) do you want ongoing monitoring or a one-time-and-done treatment.

WDI reports — what they actually mean

A Wood Destroying Insect Report (WDI, sometimes called a “termite letter” or NPMA-33 form) is a real estate transaction document. It states whether the inspecting company found evidence of current or previous WDI activity. It is not a warranty against future termites. It is not a certification that the property is termite-free.

A clean WDI report says: at the time of inspection, the inspector did not observe evidence of WDIs. It can also note “previous activity, treated” with treatment details. The most common transaction issue is a report that comes back with “evidence” — which can range from a single old mud tube on a pier to active galleries in structural framing. The seller is usually responsible for treatment under typical Texas real estate contracts; the buyer should not accept “we already had it sprayed once” without documentation.

What separates good from bad in termite work

Inspection thoroughness. A real termite inspection takes 45 minutes to an hour and a half for a typical home. The inspector goes into the attic, the crawl space if accessible, checks the perimeter, probes suspicious wood, and documents every observation with photos. A 15-minute walk-around is not an inspection.

Treatment documentation. Whoever does the treatment should provide a treatment graph showing exact application points, product, concentration, volume applied per linear foot, and date. This is your record for warranty claims and for future real estate transactions.

Annual re-inspection. Termite treatment isn’t set-and-forget. The best companies include annual re-inspection in the warranty term. If something goes wrong (chemical breakdown, soil disturbance, addition or remodel), you find out at year one, not year eight.