Western Drywood Termite (Incisitermes minor): Identification, Signs and Treatment in Southern California
If you live in Southern California and found termite pellets, this is most likely the termite that left them. Here is what is worth knowing about it.
The western drywood termite (Incisitermes minor) is California’s most common drywood termite and, after subterranean termites, its most important termite pest, according to the University of California. It lives entirely inside dry, sound wood with no soil contact, in small colonies (usually fewer than 1,000) that take years to mature. You usually find it through its six-sided pellets piling up under tiny kickout holes, or its daytime swarms in summer and fall. It is a native insect that originally lived in dead wood along rivers, washes and arroyos; in San Gabriel Valley homes it turns up in eaves, fascia, window and door frames, attics, patio covers and furniture. Limited, accessible infestations can often be treated locally without a tent; widespread or hidden ones call for fumigation.
Local help: Found pellets, mud tubes or wings? Text a photo to (626) 409-1584 and we will tell you what it is and whether it needs an inspection. Quotes from photos are free.
On this page
Western drywood termite at a glance
| Detail | What to know |
|---|---|
| Scientific name | Incisitermes minor |
| Family | Kalotermitidae (drywood termites) |
| Status in California | The most common drywood termite, and the second most important termite pest after subterranean termites |
| Native? | Yes; it originally lived in dead wood in trees along rivers, washes and arroyos |
| Range | The Pacific coast, the Central Valley and the deserts of Southern California; drywood termites are most prevalent in Southern California |
| Soil contact | None needed; the colony lives inside the wood |
| Colony size | Usually fewer than 1,000, and it takes years to mature |
| What it infests | Dry, sound wood: structural lumber, decks, fences, utility poles, stored lumber, furniture and dead tree limbs |
| Swarms | In daylight in summer and fall; in the San Gabriel Valley, peaking in August and September |
| Signature evidence | Six-sided pellets under kickout holes smaller than 2 mm |
| Look-alikes | Dampwood termites, wood-boring beetles and carpenter ants |
| Treatment | Localized treatment for limited, accessible activity, or whole-structure fumigation |
How to identify it
You will rarely see the termite itself. As the University of California puts it, drywood termites live deep inside wood and are seldom seen except when they swarm or when infested wood is opened up. What you are more likely to see:
- Swarmers: winged termites with four equal-length wings and straight, beaded antennae, flying on warm days in summer and fall. Drywood termites are larger than our subterranean termites; dampwood termites are larger still and come to lights after dark.
- Shed wings: small piles of identical wings on sills and floors after a swarm.
- Pellets: hard pellets with six flattened sides and ridges along their length, piling up on sills, floors or the garage slab under the wood they came out of. The University of California calls them diagnostic for drywood termites.
- Kickout holes: tiny round holes, smaller than 2 millimeters, that the termites use to push pellets out of the wood.
- Galleries: if the wood is opened, chambers and tunnels that cut across the grain, some packed with pellets, clean rather than soil-filled.
Not sure what you are looking at? The termite evidence guide goes sign by sign.
Where it lives in a Southern California house
The western drywood termite is native here. Long before houses, it lived in dead wood in trees along rivers, washes and arroyos, which describes a lot of the San Gabriel Valley. Its swarmers fly out to infest nearby wood, and a house offers plenty of dry, sound wood to land on.
In the houses we inspect, that means rafter tails and fascia under the eaves, barge boards, window and door frames, garage door headers, patio-cover beams, attic framing and wooden furniture (termites in furniture has more on that). Because colonies are small and can be spread out, one house can have several, in different boards.
Is it active? The pellet test and the look-alikes
Pellets tell you drywood termites have been there, not that they still are. The University of California notes you can’t tell from pellets alone whether an infestation is active or how far it extends. The simple test: clean up the pellets under a kickout hole and look again a few days later. A fresh pile means an active colony; a few grains can just be building vibration.
Three things get mistaken for drywood termites. Dampwood termites leave pellets that are rounded at both ends and lack the ridges, and they need wet, decaying wood. Wood-boring beetles and carpenter ants leave different debris; our termite droppings guide shows the difference, and is termite damage old or active? covers what old damage looks like.
When western drywood termites swarm
Western drywood termites swarm during the day in summer and fall. In the San Gabriel Valley the peak is August and September, often on hot afternoons as a heat wave breaks. Because colonies are small, the swarms are small too, and a handful of swarmers coming out of the same window frame is a real colony in that frame. Here is when flying termites are worth worrying about.
Drywood vs. subterranean vs. dampwood
| Feature | Western drywood | Western subterranean | Dampwood |
|---|---|---|---|
| Where the colony lives | Inside dry, sound wood | In the soil | In damp, decaying wood |
| Needs soil or moisture? | No | Yes, soil and moisture | Wet wood |
| Colony size | Small, usually under 1,000 | Can reach hundreds of thousands | Varies |
| Evidence you find | Six-sided pellets, kickout holes | Mud tubes, soil-packed damage | Rounded pellets, wet rotted wood |
| Swarms here | Daytime, summer and fall | Afternoons after spring rain | Summer and fall, at lights after dark |
| Treatment | Localized treatment or fumigation | Bait stations or soil treatment | Fix the moisture, replace the wood |
How it is treated
Every drywood treatment is either whole-structure or localized, and the University of California is clear that they are not equal. A whole-structure treatment (fumigation) treats every infestation at once, including hidden ones; occupants, pets and plants leave for several days, and a monitored fumigation has the highest success rate. A localized treatment works on a board or a small group of boards. It is very effective when the colony is found and the treatment reaches it, but no one can be certain a localized treatment caught every colony in a house.
That is why we inspect first and say which one your house needs. When the activity is limited to areas an inspection can find and reach, localized treatment injects foam into the galleries in one visit, you stay home, and it carries a two-year written warranty. When it is widespread or hidden, fumigation is the honest answer (spot treatment vs. tenting). Either way, the annual termite program re-inspects the house each year, and the University of California itself suggests considering an annual inspection service when choosing a drywood treatment.
The University of California also suggests comparing more than one inspection report before choosing a company. We agree; here are 12 questions to ask a termite company.
Keeping new colonies out
New colonies start when swarmers find exposed, unprotected wood, so the practical defenses are keeping exterior wood painted and sealed, keeping vent screens intact, and catching new activity early. The University of California notes that pressure-treated wood and wood preservatives are widely used in California but can perform below expectations, and that paint, screens and resistant woods are reasonable barriers without much field data behind them. The most reliable prevention is still an inspector’s eyes on the house on a schedule; here is how often that should be, and how to prevent termites covers the rest.
Sources
Common Questions
Quick Answers.
What does a western drywood termite look like?
You rarely see the termites themselves. Swarmers have four equal-length wings and straight, beaded antennae and are larger than subterranean termites. The usual signs are six-sided pellets, tiny kickout holes and shed wings.
Where do western drywood termites live?
Inside dry, sound wood, with no soil contact: eaves, fascia, window and door frames, attic framing, patio covers, fences, decks and furniture. The species is native to California and originally lived in dead wood along rivers, washes and arroyos.
How big is a drywood termite colony?
Small. The University of California puts western drywood colonies at usually fewer than 1,000 termites, and they take years to mature. A house can have several separate colonies in different boards.
Do drywood termites need soil or water?
No. Drywood termites nest inside the wood and do not need soil contact, which is why they can infest attics, furniture and second-story trim.
When do western drywood termites swarm?
During the day in summer and fall. In the San Gabriel Valley the peak is August and September, often on hot afternoons as a heat wave breaks.
What do drywood termite droppings look like?
Hard pellets with six flattened sides and ridges along their length, often in small piles that look like coarse sand or ground pepper under the wood they came from. The University of California calls them diagnostic for drywood termites.
How can I tell if drywood termites are still active?
Clean up the pellets under a kickout hole and look again a few days later. A fresh pile means an active colony; a few grains can just be building vibration. Pellets alone can’t tell you how far an infestation goes.
Can drywood termites be treated without tenting?
Often, when the activity is limited to areas an inspection can find and reach. Localized treatment puts the product directly into the galleries. When activity is widespread or hidden, fumigation is the treatment that reaches every infestation at once.
Is the western drywood termite native to California?
Yes. The University of California notes it has been here for millions of years, mostly infesting dead wood in trees along rivers, washes and arroyos.
Can drywood termites spread from a neighbor’s house?
Their swarmers fly to nearby wood to start new colonies, so drywood activity on a block is shared. A neighbor’s infestation is a good reason to check your own exposed wood, not proof that you have them.
Keep Reading
About the Author
Joshua A. Westad 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 your job stays under licensed ExterMetro oversight from inspection through follow-up.