Drywood vs. Subterranean Termites: Which Does Monterey County Have?

The Short Answer: Monterey County Has All Three

Unlike most inland California counties where subterranean termites dominate, coastal Monterey County supports all three structural termite species simultaneously. The coastal fog belt, the prevalence of older wood-frame construction, and the mild year-round temperatures create conditions that favor each species in different parts of the county:

• Drywood termites — dominant in coastal communities: Monterey city, Pacific Grove, Carmel, Carmel Valley, and older Salinas neighborhoods. Any wood-frame home in these areas should be considered at risk.
• Subterranean termites — present throughout the county, especially in areas with moist soil: the Salinas Valley floor, areas with irrigation, homes with poor drainage or wood-to-soil contact.
• Dampwood termites — found in moisture-damaged or high-humidity structures throughout the coastal zone. Common in Santa Cruz County but present in Monterey County as well, particularly in structures with active water damage or in redwood-framed buildings.

Drywood Termites: What to Look For

Drywood termites (Incisitermes minor and related species) live entirely within dry wood — no soil contact, no moisture required. They're the dominant structural pest in coastal California for good reason: the old-growth fir and redwood framing in pre-1960 coastal homes provides ideal food and nesting conditions.

• Key sign: Fecal pellets. Drywood termites eject their feces through kick-out holes in infested wood. Look for tiny (1mm), 6-sided, wood-colored pellets accumulating on horizontal surfaces below infested wood — windowsills, attic floors, shelving.
• Key sign: Kick-out holes. Small, perfectly round holes (about 1mm diameter) in wood surfaces, often with a thin membrane that breaks open.
• Damage pattern: Smooth galleries cut across the wood grain. Cross-sections of infested wood look like a series of parallel tunnels with clean walls.
• Location: Attic framing, window and door frames, fascia boards, and any exposed wood on the structure's exterior. Rarely in the crawl space (too much moisture).
• Treatment: Fumigation for widespread infestation; orange oil or direct injection for isolated areas.

Subterranean Termites: What to Look For

Western subterranean termites (Reticulitermes hesperus) are the most destructive termite species in North America. Unlike drywood termites, they live in underground colonies and must maintain soil contact for moisture. They access structures by building mud tubes.

• Key sign: Mud tubes. Pencil-width tubes of mud and feces running from the soil up foundation walls, concrete piers, or sill plates. This is the most reliable indicator of active subterranean infestation.
• Key sign: Swarmer wings near soil level. Subterranean swarmers emerge from the ground or from mud tubes at ground level, not from wood surfaces.
• Damage pattern: Hollow wood with a layered, laminated appearance — the termites eat along the grain, leaving thin wood walls between galleries that collapse under pressure.
• Location: Crawl space framing (sill plates, joists, girders), lower wall framing, any wood with soil contact. They can also build mud tubes over concrete to reach wood above.
• Treatment: Liquid termiticide soil treatment (Termidor) applied around the foundation perimeter. Borate treatments for accessible framing.

Dampwood Termites: The Moisture Indicator

Dampwood termites (Zootermopsis species) are the largest termite species in California — swarmers can reach 1 inch in length. They require wood with above-normal moisture content to survive. Finding dampwood termite activity is almost always a sign of an underlying moisture or structural problem.

• Key sign: Large fecal pellets. Dampwood pellets are larger than drywood pellets and tend to stick together or remain inside galleries.
• Key sign: No mud tubes (unlike subterranean). No fecal pellet piles on surfaces (unlike drywood). Activity is usually detected only when infested wood is opened.
• Location: Wood in contact with soil, wood exposed to persistent leaks, crawl space members affected by condensation or drainage issues, and redwood-framed structures.
• Treatment: Source of moisture must be addressed first — without correcting the moisture problem, dampwood termites will return regardless of treatment. Direct wood treatment for infested members; structural repair for damaged sections.

Why Misidentification Is Expensive

A homeowner treating for subterranean termites when drywood is the problem will spend $500–$1,500 on soil treatment that has zero effect on the actual infestation. A homeowner who fumigates (appropriate for drywood) when the problem is subterranean will eliminate any drywood activity in the structure but leave the subterranean colony untouched — and the mud tubes return within months. We've re-treated homes where the previous contractor applied the correct treatment for the wrong species. The only way to avoid this is a professional inspection by a licensed structural pest control technician who correctly identifies what's present before recommending treatment.

The Inspection: What Gets Checked

A comprehensive WDO inspection for Monterey County properties covers all accessible areas — attic (drywood activity, damaged framing), crawl space (subterranean tubes, moisture conditions, dampwood activity), exterior (mud tubes, damaged wood, earth-to-wood contact), and interior (signs of active infestation at windows, doors, trim, flooring). The inspector looks for evidence of all three species and documents findings in a Section 1/Section 2 report format.