Drywood vs Subterranean Termites in Los Angeles: What Is the Difference?

How are drywood and subterranean termites different?

Drywood termites nest inside the wood they eat and need only the moisture in dry timber. Subterranean termites nest in soil and travel to wood through tunnels, so they need ground contact. That difference decides where you look, what the damage looks like and which treatment fits.

Both types eat wood, and both can do serious damage over time, but they live in different places. A drywood colony lives inside the timber it eats. A subterranean colony lives underground and reaches wood through soil contact.

That is why a dry climate is no protection. Los Angeles has long dry months, low rainfall in summer and a lot of wood-framed housing, and drywood termites are built for exactly that: they extract what water they need from the wood itself and the dry air around it. Subterranean termites also thrive here, working from soil moisture beneath raised foundations and next to slabs.

The table below sets the two side by side. Where the location sourcing is general rather than local, we say so, and the right answer for your house always comes from an inspection.

Why does a dry climate make drywood termites a Southern California problem?

Drywood termites need no soil moisture, so dry wood in attics and roof framing is ideal. The western drywood termite is found along the Pacific coastal region into the Central Valley and deserts. In a city with long rainless months and plenty of exposed wood trim, dry timber is everywhere.

A drywood colony starts when a swarming pair lands on a piece of dry wood, finds a crack or a gap near a vent, and chews inside. From there it grows slowly. Because the colony stays hidden inside the timber, a homeowner may live with it for years without seeing anything but the occasional pellet.

Los Angeles has a lot of housing with exposed wood in the places drywood termites like. Craftsman bungalows in Pasadena's Bungalow Heaven and Highland Park-Garvanza have visible rafter tails and wood trim, while 1920s period-revival houses in Hancock Park and Leimert Park have their own eaves, fascia and attic framing. We do not claim that any one neighbourhood has more termites than another, only that these are the kinds of wood a technician checks.

The wider point is that you do not need damp conditions for termites in this city. A dry attic is not a safe attic. If you want to see how drywood termites fit into the year, the Los Angeles pest calendar shows when swarmers typically fly.

What are the signs of each type, and when do they swarm?

Drywood termites leave small hexagonal pellets from kickout holes and shed wings after daytime swarms in summer and fall. Subterranean termites swarm on calm sunny days right after the first autumn rains and may also swarm in spring, especially in southern California. Both types call for an inspection.

Drywood pellets are the most useful clue because they are hard to mistake once you know the shape. They are small, hexagonal and often collect in a little pile beneath a kickout hole, a pinhole the colony uses to push waste out of its gallery. Swarmers fly in the daytime in summer and fall, tending to late summer or early fall in coastal and southern regions, and they leave behind discarded wings.

Subterranean termites work from soil contact, so an inspector looks at wood near the ground, foundations and slab edges. UC sources say they swarm on calm sunny periods right after the first autumn rains, and may also swarm in spring, especially in southern California.

Do not try to confirm the species from a photo of one insect or one wing. A technician will usually collect a sample, check the wood and look at where it sits in the building, which usually settles the question.

• Small hexagonal pellets collecting below a hole in wood
• Piles of shed wings on windowsills after a warm day
• Swarming insects in or near the house right after the first autumn rain

What is the difference between fumigation and local treatment?

Fumigation, or tenting, treats the whole structure with a lethal gas and is licensed as its own category, Branch 1. Local treatment targets specific spots with products or wood replacement. UC IPM notes that limited drywood infestations can be handled by replacing wood, while extensive ones typically need chemical treatment of the structure.

The Structural Pest Control Board licenses structural pest work in three branches: Branch 1 for fumigation, Branch 2 for general pest, and Branch 3 for termites, wood-boring beetles, dry rot and fungus. A company that tents a house must be licensed for fumigation, which is why fumigation and local termite work can be separate parts of a business.

Fumigation reaches the places a technician cannot, such as framing inside walls and wood buried behind finishes. It needs the household to leave, usually with food, medicines and plants removed or bagged, and the structure is covered and sealed during treatment. Local treatment is less disruptive and can fit a single, well-defined area, but it only treats the wood it can reach. Whichever method is used, ask what it covers and what it does not.

For a deeper look at tenting, see our termite fumigation page, and for the other side of the choice, drywood termite control and subterranean termite control cover local methods.

What is an inspection report, and why does it matter when buying a home?

A Wood Destroying Pests and Organisms Inspection Report documents termite and wood-decay findings and recommended work, and it is commonly used in California home sales under the Structural Pest Control Act. The registered company must file the property address with the Board within 10 business days of the inspection or the work.

In California real-estate sales, a buyer or seller will often order an inspection report. The report names what the inspector found, such as drywood pellets, subterranean activity or fungus damage, and lists the work recommended. Under Business and Professions Code section 8516(b), a registered company must report each inspected property to the Board no later than 10 business days after the inspection starts or the work is complete, and failing to file can lead to discipline and a fine of up to $2,500.

Copies of reports filed with the Board over the preceding two years can be obtained. That means a buyer can look at a property's recent history, and a seller can confirm that earlier work was filed. We do not state the filing fee, since we could not confirm one.

The report separates findings from recommendations. A finding is what was seen. A recommendation is a proposed fix and its price, and you are entitled to compare it with another company's. Our termite inspection page describes what an inspector checks.

How do I decide what to do about termites in my house?

Start with an inspection to learn the type, the extent and the access, and ask each company to explain its recommendation and what it covers. Compare scope, not only price. A technician will tell you whether the evidence points to drywood or subterranean activity, and whether local work or fumigation fits.

Do not delay when you find pellets or signs of activity near soil, but do not panic either. Termite damage is usually slow, and a day's wait to arrange an inspection is not what decides the outcome. What matters more is that the person who looks is qualified, explains what they see and puts the plan in writing.

Ask the company for its licence number before work starts, and ask which branch the proposed work falls under. A Field Representative can inspect, bid and contract for a registered company, while only a licensed Operator qualifies a company. Those details are in the licence, which a real company shows without argument.

If you are comparing two plans, line up the scope. One may fumigate the whole house and the other may treat the attic and replace some wood. Our pest control cost guide shows published price ranges for each approach, with the publisher and scope named.