Subterranean vs Drywood Termites — What Sydney Homeowners Actually Face

A lot of what you'll read online about termites is written for North American conditions — Formosan subterranean termites, eastern drywood termites, western drywood termites. These species are serious problems in the US. Most of them don't live in Sydney. The advice built around them doesn't fully apply here either.

Understanding what termite species are actually active in the Sydney metro area matters because it shapes what an inspection is looking for, what treatment is appropriate, and what conditions in your home are genuinely high-risk versus not.

Subterranean termites in Sydney — the species that cause damage

The termites responsible for structural damage in Sydney and across NSW are subterranean species — colonies that live in and travel through soil, maintain connection to ground moisture, and access timber structures from below.

The two subterranean species behind most structural damage in NSW are Coptotermes acinaciformis and Schedorhinotermes species.

Coptotermes acinaciformis is the termite species responsible for most structural damage in Australia. Colonies can exceed one million individuals; foraging territories can extend 50–100 metres from the nest. They favour moisture-affected timber but will attack sound structural framing given access. Their nests are often in tree root systems or in subfloor soil — rarely visible from the surface. Activity is hidden: mud tubes inside wall cavities, galleries eaten into timber from the inside, no external signs until damage is advanced or a routine inspection turns it up.

Schedorhinotermes species are multi-caste (they have more than one soldier caste — a useful identification marker) and are common in coastal NSW. They prefer timber with elevated moisture content and are associated with older properties where subfloor conditions have degraded. They're less aggressive than Coptotermes in terms of colony size, but their activity patterns make them harder to detect — smaller mud tubes, subtler entry points.

Both species are soil-based. Both need moisture. Both travel in enclosed mud tubes when crossing exposed surfaces. And both are addressed by the same treatment approach: soil barriers, baiting systems, or a combination.

Drywood termites — the species you mostly don't have

Drywood termites (principally Cryptotermes species in Australia) live entirely within dry timber — no soil contact, no moisture dependency. Their colonies are small — typically a few thousand individuals rather than hundreds of thousands. They produce distinctive frass: small, oval pellets with a ridged surface that drop from tiny kickout holes in infested timber.

In Australia, drywood termites are predominantly found in tropical and subtropical coastal regions — northern Queensland, the Northern Territory, and parts of coastal northern NSW. In the Sydney metropolitan area, drywood termite infestations are uncommon. They occasionally occur in imported furniture or timber, or in properties where infested material has been transported from further north, but they're not the standard threat Sydney homeowners are managing against.

The treatment approach for drywood termites is also completely different from subterranean: soil barriers are irrelevant (there's no soil connection); the treatment is timber-direct — fumigation or timber injection. Applying subterranean-focused treatment to a drywood infestation achieves nothing.

This is why identification matters. A pest inspector who sees damage signs in timber and assumes subterranean — without checking for the frass pellets, the tight galleries, and the absence of mud tubes that characterise drywood — may misdiagnose the problem and recommend treatment that doesn't address it.

Why this distinction matters for treatment

The treatment pathway for subterranean termites is built around soil. Chemical barrier treatment applies termiticide to the soil around the foundation, creating a treated zone that kills foraging workers when they cross it and — in the case of non-repellent termiticides like fipronil — carries the lethal dose back to the colony through grooming and food transfer. Baiting systems place bait stations in the soil around the perimeter; termites find and consume the bait; it's distributed through the colony.

Neither approach does anything useful against drywood termites, because drywood termites don't travel through soil.

In Sydney, the assumption for an active infestation is almost always subterranean. The inspection is looking for mud tubes, soil-moisture conditions, subfloor access, and the patterns that match Coptotermes or Schedorhinotermes behaviour. That's where the effort is directed, and that's where the treatment is designed.

If an inspection finds something inconsistent with subterranean behaviour — frass pellets without mud tubes, damage in isolated high-set dry timber with no subfloor connection, tight sealed galleries — that warrants investigation for drywood species or wood borers before a treatment approach is locked in.

What about other timber pests?

Wood borers (Lyctus, Anobium, and other species) and decay fungi are separate categories entirely. They're covered by the timber pest inspection scope — the "timber pest inspection" component that sits alongside the termite inspection in any pre-purchase brief. But they're not termites, they don't behave like termites, and their treatment isn't the same.

Borers leave round exit holes and fine frass. Decay fungi are a moisture problem requiring the moisture source to be fixed and the affected timber replaced. Confusing these with termite activity — or assuming they'll be caught in a termite-only inspection — is a scope mistake.

What this means if you're in Sydney

If you're a Sydney homeowner concerned about termites, the species you're dealing with is almost certainly subterranean — Coptotermes or Schedorhinotermes. The inspection is looking for their specific signs. The treatment approach is built around soil management and colony disruption.

I'll confirm what you're dealing with on the inspection and give you a straight assessment of what the right treatment path looks like for your specific property.

Book at activetermitecontrol.com.au or call 0405 790 927.