Formosan Termites in San Antonio, Texas

Formosan termites have been detected in Bexar County: Texas A&M's Center for Urban & Structural Entomology includes Bexar on its list of Texas counties with Formosan finds. That list records detections, though, not how common they are, and Texas A&M says the upper Gulf Coast is where they are most likely to turn up. For San Antonio homeowners, the practical takeaway is to know what a Formosan swarmer looks like and to get any suspected find identified, because their colonies are far larger than native termite colonies.

If you have seen swarmers around your lights at night in late spring, call or text (210) 281-1064 or book a termite inspection.

Are Formosan termites in San Antonio? #

Here is what the sources actually say:

• Texas A&M's urban entomology center reports Formosan termites detected in 31 Texas counties "with more being added each year." Bexar, Comal and Hays counties are on that list.
• Kendall, Guadalupe and Medina counties are not on it.
• The center says the upper Gulf Coast is where they are most likely found, but homeowners anywhere in the state should watch for isolated infestations.
• Texas A&M's Insects in the City (ENT-2002) describes Formosan termites as established in a few upper Gulf Coast communities, with isolated detections in central and north-central Texas that appear tied to recycled railroad ties.

So Formosan termites have been found in the San Antonio area, but none of these sources describes them as widespread here. Native subterranean termites remain the termite most local homes deal with.

What the list means for nearby towns #

The county records line up with the towns around San Antonio in a few useful ways. Helotes sits in Bexar County. Bulverde is a Comal County city, and Comal is also on the detection list. Boerne is the Kendall County seat, and Kendall is not listed. Fair Oaks Ranch spreads across Bexar, Kendall and Comal counties. None of this means a given neighborhood has or lacks Formosan termites; it only shows where Texas A&M has recorded them.

How do Formosan termites travel to new places? #

Formosan termites mostly spread across Texas inside moved wood rather than by flying. AgriLife's Formosan termite bulletin (E-367) points to recycled railroad ties and shoring timbers, moved from infested areas and reused in yards, as the main way they reach new places. The bulletin adds that creosote-treated wood is not a reliable barrier against them.

If you are planning raised beds, retaining walls or borders, skip used railroad ties and old shoring timbers. If they are already in your yard, mention them during your inspection.

Spotting a Formosan swarmer at your porch light #

Formosan swarmers look and behave differently from the native termites most people see:

• Color and size: yellowish brown and larger, about 0.5 to 0.6 inch, compared with the dark, roughly 3/8-inch native swarmer
• Wings: covered with fine gold to reddish hairs
• Timing: at night, drawn to porch lights and windows, in early May through June by AgriLife's count, or late May and early June by the urban entomology center's
• Soldiers: teardrop-shaped heads that ooze a sticky white fluid when disturbed

Native termites, by contrast, swarm in daylight and start much earlier in the year. Our termite swarmers page has a month-by-month comparison.

Why is a Formosan colony a bigger concern? #

AgriLife reports that Formosan colonies are at least four times the size of native colonies and can grow past a million termites within five years. More termites means faster damage. The bulletin also notes that they:

• Can build "carton" nests inside walls when a moisture source is available, with no connection to the ground
• Attack more than 50 kinds of trees
• Can chew through plastic and rubber, and have caused electrical shorts and house fires

That is why moisture problems inside walls, such as plumbing or roof leaks, get close attention when Formosan termites are suspected. See termite damage in San Antonio for how damage is assessed.

Seen night swarmers in May or June? What to do #

• Turn off unneeded outdoor lights during the swarm so fewer insects gather at the house.
• Collect several swarmers or soldiers in a sealed bag for identification.
• Note where they gathered: inside near a window, around one fixture, or outside only.
• Don't spray or tear into walls before the inspection.
• Check the yard for used railroad ties or timbers.

How Pest Trappers handles a suspected Formosan infestation #

A Pest Trappers technician identifies the termite first, since a Formosan find changes how much attention moisture sources and wall voids need. The inspection covers the foundation, plumbing areas, walls near leaks, the attic and yard timbers. The technician then explains the treatment options that fit, follows every product label and quotes the price after the inspection. Termite services come from Pest Trappers LLC (TPCL #0887549), licensed by TDA in the termite category.

We serve San Antonio, Helotes, Bulverde and Fair Oaks Ranch. For the other termites in the area, see types of termites in San Antonio or the termite fact sheet.

Frequently asked questions #