Drywood Termites in Structures: Identification, Treatment Decisions, and Procurement Guide

Drywood termites live inside dry, sound wood. Colonies are small, hidden, and slow-growing—but persistent. Your playbook is simple: confirm the pest correctly, choose whole-structure vs localized treatment based on spread and access, then close with prevention and monitoring. For procurement, prioritize IRAC-mapped actives, fit-for-purpose formulations (foam, dust, RTU), and licensed delivery.

Fast Identification: Reduce Misdiagnosis Risk

• Swarmers (winged termites): often daylight flights in warm seasons; shed wings near windows and lights.

• Pellets (frass): dry, hard, six-ridged “football” granules; often pile beneath tiny “kick-out holes.”

• Differentiate from look-alikes:

  • Dampwood termites: prefer wet/decayed wood; fix moisture and you remove the habitat.

  • Carpenter ants/beetles: push out sawdust-like frass; gallery architecture and pellets differ.

Actionable checkpoint: If pellets re-accumulate after cleaning, you likely have active galleries.

Decision Framework: Whole-Structure vs Localized

Use this simple decision tree to drive scope, budget, and timeline.

1. Are signs widespread across multiple areas or inaccessible voids?

   • Yes → Whole-structure treatment for complete coverage.

   • No → Localized treatment focused on detected galleries.

2. Operational constraints (family, tenants, business hours)?

   • Strict downtime limits may push you to localized or heat solutions in zones.

3. Risk posture & warranty

   • If you must minimize re-work risk in a complex structure, whole-structure typically carries higher confidence and clearer warranty terms.

Whole-Structure Treatments (High Coverage, No Residual)

Fumigation (sulfuryl fluoride)

• What it does: Penetrates the structure and eliminates hidden colonies in one cycle.

• When to choose: Multiple rooms/levels affected, complex architecture, uncertain colony locations.

• Considerations: Requires licensed professionals, temporary vacancy, and gas monitoring. No residual—pair with prevention.

Whole-house heat

• What it does: Elevates wood core to lethal temperature for a sustained period.

• When to choose: Clients sensitive to fumigants, or where chemical access is constrained.

• Considerations: No residual; large beams and “heat sinks” need careful monitoring; still professional work.

Localized Treatments (Targeted, Access-Dependent)

Localized heat / microwave

• Use case: Furniture, wall sections, trim, localized beams.

• Strengths: Non-chemical, fast turnaround, minimal disruption.

• Limits: Efficacy hinges on accurate detection and material thickness.

High-voltage electrocution

• Use case: Select structural elements with clear access.

• Limits: Interference from metal/concrete/glass; specialized equipment and trained operators required.

Wood removal & replacement

• Use case: Severely damaged or easily accessible members.

• Strengths: Removes damage and insects simultaneously; ideal for finishes/restorations.

• Limits: Requires carpentry and, for load-bearing members, engineering review.

Localized insecticide delivery (foam/injection/dust)

• Use case: Confirmed galleries behind walls, in trim, frames, or voids.

• Strengths: Penetration into galleries with residual performance (depending on active/formulation).

• Limits: Demands precise detection; drilling/void access; label compliance by use site.

Recommended Actives & Formulations (Label-Dependent, No Rates)

Compliance first: Always align with local registrations, labeled use sites, and license requirements. The list below is for procurement scoping—not application instructions.

Localized injection / foam (gallery access)

• Fipronil (IRAC 2B) — foam/SC/RTU foam

  • Role: Core localized active with strong performance in drywood galleries.

  • Where it fits: Wall voids, window/door frames, trim, beams with drill access.

• Imidacloprid, Dinotefuran (IRAC 4A) — foam/liquid

  • Role: Systemic/slow-acting options; useful as rotation or supplementary chemistry.

Contact/residual for surfaces & crevices

• Pyrethroids (IRAC 3A) — e.g., bifenthrin, cyfluthrin, cypermethrin, lambda-cyhalothrin

  • Role: Fast knockdown, residual barrier on treated surfaces/crevices.

  • Note: Limited penetration; accuracy and coverage matter.

• Chlorfenapyr (IRAC 13)

  • Role: Alternative residual for rotation and resistance management in labeled structural contexts.

Wood treatment / prevention (construction & rehab)

• Borates (IRAC 8D) — disodium octaborate tetrahydrate and related borate systems

  • Role: Penetrative wood treatment for prevention and accessible repairs; valuable in remodels and new builds.

• Desiccant dusts (silica aerogel, etc.) — IRAC not applicable

  • Role: Drying action in voids and dead spaces; adjunct to foam/injection work.

Not a first-line path for drywood

• Termite baits (IGR; IRAC 15) are primarily designed for subterranean termites. They are not the mainstream solution for drywood colonies residing entirely in wood above ground.

Program Templates (Adapt to Site, Label, and License)

Scenario A — Widespread, multi-room evidence

• Treatment: Whole-structure (fumigation or heat).

• Close-out: Post-treatment inspection, seal kick-out holes and entry points, discuss preventive borate treatments during future renovations.

Scenario B — Localized signs in reachable voids

• Treatment: Map galleries → Drill/void access → Foam/injection with a 2B or 4A option per label → Optional desiccant dust for dead spaces.

• Close-out: Finish repairs, paint/seal, schedule follow-up inspections.

Scenario C — Furniture or discrete architectural elements

• Treatment: Localized heat or microwave; for restorations, consider removal/replacement plus borate treatment on new wood.

• Close-out: Seal and finish; maintain records for warranty continuity.

Prevention by Design (Lower Recurrence, Lower TCO)

• Seal pathways: Tighten joints, caulk cracks, screen vents, and protect end-grain exposures.

• Healthy envelopes: Maintain paint/finish integrity; avoid wood-to-wood traps that hide pellets.

• Smart materials: Where permitted, use borate-treated lumber in remodels; select designs that allow inspection access.

• Monitoring: Regular inspections after any treatment—early detection cuts cost.

Compliance & Safety

• Licensed professionals only for fumigation, whole-house heat, electrocution, and many localized insecticide uses.

• Occupant safety: Temporary vacancy may be required; follow re-entry and clearance protocols from the service provider.

• Label is law: Use pesticides safely. Always read and follow label directions, including REI/PHI where applicable.

• Documentation: Capture SDS, COA, equipment safety information, warranty terms, and service logs for audit readiness.

Procurement Guide (What to Buy and Why)

Chemistry portfolio (by role)

• Core localized foam/injection: Fipronil (2B) as primary; Imidacloprid/Dinotefuran (4A) for rotation.

• Residual adjuncts: Pyrethroid (3A) or Chlorfenapyr (13) per labeled sites.

• Wood treatment: Borate concentrates for brush/spray/soak; desiccant dusts for voids.

Formulation & packaging

• Foams/RTU foams for gallery saturation and cling;

• SC/EC/CS where surfaces/crevices are labeled;

• Dusts for dry voids;

• Borate solutions for accessible wood.

• Offer private-label OEM in professional pack sizes with multi-language labels.

Technical file

• Provide SDS/COA, stability data, and HPLC release records.

• IRAC mapping on labels and spec sheets to support resistance-smart programs.

Service & training

• Verify licensing requirements by market; include quick-start operator briefs, safety checklists, and inspection templates for professional teams.

FAQ (Client-Facing)

Q1. Will whole-structure treatments prevent future infestations?
No. They eliminate current colonies but leave no residual. Combine with sealing and, during renovations, borate treatments.

Q2. When are baits a good option?
Baits target subterranean termites. Drywood termites live entirely in wood; baits are not a primary solution.

Q3. We only found pellets in one room. Is localized treatment enough?
If inspection confirms it’s truly confined and accessible, localized can be cost-efficient. Build in follow-ups and consider borates during any repairs.

Q4. Heat or fumigation—how do we choose?
Pick based on coverage needs, occupant constraints, and local availability. Both lack residual; prevention steps remain essential.

Q5. Can we DIY with store products?
Structural drywood control typically requires licensed professionals and specialized equipment. Stick to professional service for safety, efficacy, and warranty.

How We Can Help

For registered markets, we supply MOA-mapped portfolios (2B/4A/3A/13/8D), OEM/ODM formulations (foam, RTU, SC, dust, borate), multi-language labels, and full technical dossiers. Share your target countries and current SKUs; we will deliver a MOA × use-site × formulation matrix and a buyer-ready comparison table to accelerate sourcing and compliance review.