Shelter tubes
Earthen tubes may run from soil to wood, across masonry, behind stucco, or through concealed building spaces.
Subterranean Termite Control & Prevention in San Diego
Professional identification, soil treatment, baiting, moisture correction, and monitoring selected around the structure and the evidence found.
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Control starts below the visible damage
Subterranean termites move between soil and structural wood
Native subterranean termites are widespread in California and can reach a structure through soil, foundation joints, plumbing penetrations, bath traps, crawlspace piers, and other concealed routes. Their shelter tubes help protect workers as they travel between the colony's foraging network and wood or another cellulose source. A tube may appear on concrete, masonry, stucco, framing, or an interior surface even though termites do not consume concrete.
A reliable recommendation begins by confirming the termite, locating current evidence, understanding the construction, and identifying moisture or access conditions. Common native species usually remain connected to soil. The uncommon, invasive Formosan subterranean termite can sometimes establish an aerial carton nest when dependable moisture is available, so unusual activity requires careful identification rather than a routine assumption.
Our licensed inspectors evaluate visible and accessible areas and develop a property-specific plan. Learn what to expect during the termite inspection process, or use the scheduling form to tell us where you found tubes, wings, swarmers, or damaged wood.
CaliforniaCommon and widespread
Common clueShelter or mud tubes
ConcreteCrossed through openings, not eaten
First stepIdentify the route and species
Found a suspicious tube or damaged wood?
Schedule an inspection →Evidence in context
Six signs worth documenting
The location and condition of the evidence help an inspector map possible access. Photograph suspicious tubes before disturbing them; an abandoned tube does not independently confirm current activity.
Workers and soldiers
Workers are pale and soft-bodied; soldiers commonly have darker heads and larger mandibles for colony defense.
Swarmers and wings
Winged reproductives or piles of equal-sized wings can indicate a nearby colony, but outdoor swarmers do not always mean the building is infested.
Changed wood
Soft, hollow-sounding, blistered, or visibly damaged wood may conceal galleries lined with soil or termite material.
Wood-to-soil contact
Posts, siding, framing, fences, debris, or stored lumber touching soil can conceal direct access and provide cellulose.
Moisture and hidden access
Leaks, irrigation, poor drainage, blocked ventilation, and concealed foundation edges can support continued activity.
Before removing a tube:
Photograph its full route and close-up condition. A licensed inspector may open part of it to look for live termites and will determine when accessible tubes should be removed as part of treatment and monitoring.
Different termite, different treatment
Subterranean or drywood termite?
Subterranean termites
- Commonly connect to a nest or foraging network in soil.
- Build shelter tubes containing soil and termite secretions.
- Often enter through foundation edges, cracks, joints, and penetrations.
- Usually require soil, bait, targeted, moisture, or combined control measures.
Drywood termites
- Live inside relatively dry wood without a soil connection.
- Expel hard, six-sided fecal pellets through kick-out holes.
- Create comparatively clean galleries rather than soil-lined tubes.
- May require localized wood treatment or whole-structure treatment.
Structural fumigation used for drywood termites generally does not reach the reproductives and foraging network of a subterranean colony in soil. Identification must come before selecting a treatment.
Follow the route
From soil to structural wood
Workers search through an underground network while soldiers defend the colony. Mature colonies can produce winged reproductives, or alates, that disperse to begin new colonies. The route into a building may be direct or concealed behind finishes and construction joints.
- 01
Soil network
A queen and king produce a colony of workers, soldiers, immatures, and future alates. Workers forage through soil for cellulose.
- 02
Entry opportunity
Foundation edges, cracks, expansion joints, utility penetrations, bath traps, piers, or buried debris create possible routes.
- 03
Protected travel
Shelter tubes maintain a protected travel path across exposed or concealed surfaces between soil and a feeding site.
- 04
Cellulose source
Workers reach framing, flooring, posts, siding, paper-faced materials, or another source while remaining largely hidden.
Slab edgesExpansion jointsBath trapsPipe penetrationsCrawlspace piersLow stuccoWood-to-soil contact
Treatment selection
Four tools, selected around the property
The appropriate scope depends on confirmed activity, foundation type, soil access, drainage, prior treatments, utilities, wells or other sensitive areas, and whether evidence suggests a native or Formosan termite.
Liquid soil treatment
A registered termiticide can be applied to label-permitted soil and entry zones by trenching, rodding, or carefully placed injection. Coverage and application method depend on construction and soil conditions.
Professional bait stations
Slow-acting bait is placed where foraging termites can encounter it. Stations require correct placement, servicing, and continued monitoring rather than a one-time installation.
Targeted supplemental work
Above-ground bait, foam, liquid, or another labeled application may support a larger plan where active tubes, voids, or localized routes are accessible.
Construction barriers
Mesh, graded particle barriers, membranes, sealants, or preconstruction treatments protect specific access points when incorporated completely and correctly.
One or more tools may be combined with moisture correction, debris removal, exclusion, and repair. Explore additional termite treatment methods, but rely on the inspection and current product label for the actual scope.
Liquid soil applications
Treat the relevant soil and entry zones
Post-construction work may include trenching beside a foundation, rodding where allowed, or drilling and injecting through concrete to reach label-specified soil. Slab edges, bath traps, expansion joints, pipes, piers, and attached construction can change the application design. Before work begins, the technician must consider drains, ducts, radiant systems, plumbing, runoff, and soil conditions.
GC treatment records include Termidor SC, which contains fipronil, and Altriset, which contains chlorantraniliprole. These are different registered termiticides with different modes of action. Product choice, concentration, treated locations, precautions, and re-entry directions must follow the current label; a brand name alone does not determine the correct plan.
Termidor SCFipronil soil termiticide
AltrisetChlorantraniliprole, Group 28
Professional baiting
Slow-acting bait depends on foraging and follow-up
Subterranean termite bait combines a cellulose matrix with a slow-acting active ingredient. Foraging workers consume and share it within the colony. In-ground or above-ground stations may be selected according to the activity and site, but discovery can vary with species, season, soil, competing food, and placement.
Sentricon is one registered example. Its current Always Active approach places Recruit HD bait in stations when the system is installed rather than waiting to exchange a wood monitor after termites arrive. Sentricon is included here for education and is not presented as a GC certification or a promise that this particular branded system is available for every property.
- Station number and spacing follow the selected product label.
- Service continues after installation to inspect, maintain, and document stations.
- No fixed calendar can predict when termites will encounter or consume bait.
Physical and preconstruction protection
Barriers protect specific construction paths
Stainless-steel mesh and specifically graded particle systems can physically block termite passage around vulnerable joints or service penetrations when installed as a complete construction system. They are generally most practical before slabs, walls, and finishes close access.
Termite shields do not exterminate a colony; properly detailed shields can help force hidden tube construction into a visible area. Membranes and sealants vary: some are physical components, while others incorporate a registered pesticide. Each must be described and installed according to its system requirements.
- Incomplete seams or penetrations can become bypass points.
- Future utility work must not compromise the installed system.
- Inspection and maintenance remain necessary after construction.
Locally documented invasive termite
Formosan subterranean termites require careful confirmation
Coptotermes formosanus has been documented in limited Southern California locations, including San Diego County, but remains uncommon. Most local subterranean activity should not be labeled Formosan without identification. Suspected specimens and unusual carton material deserve professional review.
Identification clues
Swarmers are generally yellowish brown. Soldiers have rounded or oval heads, curved mandibles, and can release a white defensive secretion when disturbed.
Carton and moisture
Colonies can construct carton material from soil, wood, and secretions. Persistent roof, plumbing, wall, or other moisture can support hidden activity.
Aerial-colony exception
An aerial colony may have limited or no soil contact. In that situation, an in-ground bait or perimeter soil treatment alone may not reach the active nest.
Broader investigation
Large foraging networks and multiple feeding locations can require moisture correction, expanded inspection, targeted work, soil treatment, baiting, or another combined strategy.
Formosan identification affects treatment design. Avoid relying on colony-size assumptions, a rigid swarm calendar, or a single treatment applied before the nest and moisture conditions are understood.
Professional service process
From evidence to monitoring
- 1
Inspect and identify
Confirm the termite, examine tubes and wood, and document visible and accessible evidence.
- 2
Map the conditions
Trace soil access, foundation details, moisture, debris, previous work, and damaged material.
- 3
Select the scope
Choose liquid, bait, targeted, physical, corrective, or combined measures around the findings.
- 4
Complete treatment
Follow the approved label while protecting drains, ducts, plumbing, utilities, and sensitive areas.
- 5
Monitor and adjust
Remove accessible tubes when appropriate, review activity, maintain stations, and document follow-up.
Reduce conducive conditions
Subterranean termite prevention checklist
Maintenance cannot prevent every future infestation, but it can reduce concealed access, moisture, and food sources while making new evidence easier to see.
- 01
Control moisture
Keep crawlspaces ventilated where designed, maintain intact vent screens, and address persistent damp conditions.
- 02
Repair leaks
Correct plumbing, water-heater, irrigation, roof, and wall leaks that affect framing or soil near the structure.
- 03
Manage drainage
Direct downspouts and runoff away from foundations and correct grades or low areas that retain water.
- 04
Remove cellulose debris
Clear buried wood, cardboard, form boards, stumps, and scraps from crawlspaces and foundation edges where practical.
- 05
Store wood correctly
Keep firewood and lumber off soil and away from the exterior instead of stacking them against the building.
- 06
Maintain visible clearance
Reduce wood-to-soil contact and keep practical foundation edges visible rather than concealed by soil, mulch, or low stucco.
- 07
Maintain damaged wood
Repair deteriorated finishes and have materially weakened framing evaluated through appropriate structural repair services.
Common questions
Subterranean termite control FAQ
Inspection findings, construction, species, and access determine the practical answer for a particular structure.
Does a mud tube always mean termites are active?
No. A tube can remain after activity has stopped or after previous treatment. Its route and condition are still valuable evidence. An inspector may open a small area to look for live termites and compare it with other findings.
Can subterranean termites eat through concrete?
No. Termites consume cellulose, not concrete. They can pass through small cracks, joints, gaps around pipes, bath traps, slab edges, and other openings, then build shelter tubes across hard surfaces.
How are subterranean and drywood termites different?
Subterranean termites usually connect to soil and build shelter tubes. Drywood termites live inside relatively dry wood without soil contact and expel hard pellets. Those differences lead to different inspection and treatment strategies.
What is the difference between liquid treatment and baiting?
Liquid treatment addresses labeled soil or entry zones, while baiting relies on foraging termites finding, consuming, and sharing slow-acting bait. Construction, access, termite pressure, and monitoring needs help determine whether one or both are appropriate.
How long does subterranean termite control take?
There is no universal timeline. Treatment type, colony location, species, season, soil, access, construction, and follow-up all affect how quickly evidence changes. The proposal and product label should establish realistic service expectations.
Are Formosan termites present in San Diego?
They have been documented in limited San Diego County locations, but remain uncommon. Native subterranean termites are much more widespread. A suspected Formosan termite should be identified before changing the treatment strategy.
Reliable references
Official termite resources
UC IPMSubterranean and Other TermitesCalifornia identification, prevention, and management
UC ANRFormosan Termite AlertLocal identification and treatment considerations
U.S. EPATermite Identification and ControlTreatment categories and pesticide-label guidance
California SPCBConsumer InformationLicensing and structural pest-control resources
Start with the route and evidence
Schedule a subterranean termite inspection
We can evaluate visible and accessible evidence, construction conditions, and treatment options for your San Diego property.