Termite Facts and Statistics: What California Homeowners Should Know
How much damage do termites really do, which kinds live in California, and when do they swarm? Here are the key numbers — every figure sourced, no scare tactics.
Termites cause roughly $5 billion in U.S. property damage a year across an estimated 600,000 homes, and homeowners insurance generally excludes it as preventable maintenance. In California, two types do nearly all the damage: western drywood termites, which live inside the wood, and western subterranean termites, which nest in soil and build mud tubes. Drywood swarms fly in late summer and fall; subterranean swarms follow the rains.
Termite marketing leans on fear, so it's worth knowing the actual numbers. Here are the statistics and facts that matter for California homeowners, with a source for every figure — compiled by a licensed WDO inspector who works these houses every week.
The key numbers at a glance
| Statistic | Figure | Source |
|---|---|---|
| Property damage caused by termites in the U.S. | About $5 billion per year | National Pest Management Association |
| U.S. homes with termite damage | Roughly 600,000 per year | Industry estimates (NPMA) |
| Covered by homeowners insurance? | Generally no — treated as preventable maintenance | Standard policy exclusions |
| Termite types established in Southern California | Western subterranean and western drywood | UC Statewide IPM Program |
| Western drywood colony size | Up to a few thousand termites, growing slowly over years | UC IPM |
| Western subterranean colony size | Tens of thousands to hundreds of thousands | UC IPM |
| Queen lifespan | Can exceed a decade | Entomology literature |
| Bait-station program (subterranean treatment) longevity | Ongoing while serviced — stations opened and re-baited each year | Service program design |
| Residual protection after fumigation | None — it eliminates what's present, not what comes next | Fumigant labels |
Which termites live in the San Gabriel Valley
Two types do nearly all the damage here. Western drywood termites live entirely inside wood — eaves, attics, framing — and are the classic problem in our older housing stock; they announce themselves with six-sided frass pellets.
Western subterranean termites nest in the soil and build mud tubes up into the structure; they field far larger colonies, which is why they're considered the more destructive of the two. (A third type, the dampwood termite, needs chronically wet wood and turns up mainly where there's a moisture problem.)
When California termites swarm
Swarm timing here differs from the East Coast pattern you'll read on national sites. In Southern California, drywood swarmers fly on warm, sunny days in late summer and fall, while subterranean swarmers typically fly around seasonal rains — most often after spring rains, March through May. Piles of identical shed wings indoors are the tell either way; here's how to tell swarmers from flying ants.
What the damage numbers mean in practice
Five billion dollars a year sounds abstract until you remember two things: the damage is almost never covered by insurance, and it accumulates silently — a colony can feed for years before the first visible sign. That combination is why periodic inspections are the cheapest protection there is: the difference between a localized spot treatment and structural repair is usually just time.
Sources
Figures compiled from the National Pest Management Association, the UC Statewide Integrated Pest Management Program, and the California Structural Pest Control Board. Local seasonality reflects twelve years of San Gabriel Valley field work.
Quick Answers
Quick Answers.
How much damage do termites cause each year?
Industry figures put termite property damage at roughly $5 billion per year in the United States, affecting an estimated 600,000 homes — and homeowners insurance generally excludes it as preventable maintenance.
What kinds of termites are in California?
Two main types: western drywood termites, which live inside the wood itself, and western subterranean termites, which nest in soil and build mud tubes into structures. Dampwood termites appear where wood stays chronically wet.
When is termite season in Southern California?
Drywood termites swarm on warm, sunny days in late summer and fall. Subterranean termites typically swarm around seasonal rains, from fall through spring. Damage happens year-round — swarms are just when they're visible.
How big does a termite colony get?
Drywood colonies stay comparatively small — up to a few thousand — and grow slowly. Subterranean colonies range from tens of thousands to hundreds of thousands, which is why they're considered the more destructive type.
How reliable are these numbers?
Each figure is attributed — national data from the National Pest Management Association, California species and season facts from the UC Statewide IPM Program, and licensing facts from the state Structural Pest Control Board.
About the Author
Joshua is the owner and licensed operator of ExterMetro Termite and Pest Control in Arcadia, CA. He holds California SPCB Company Registration #8828 (Branch 2 & 3), is a licensed WDO inspector, and has worked San Gabriel Valley homes and businesses for over twelve years — hands-on in the field on every kind of job the valley throws at him.
Think you just found termite evidence?
Bag a few wings or pellets, snap a photo, and text it to (626) 409-1584 — quotes from photos are free, and the person who answers is the person who does the work.