Incisitermes spp. Krishna, 1961

Drywood termite

A termite that needs no soil at all, the whole colony lives inside a single piece of dry wood.

Order: Blattodea
Family: Kalotermitidae
Group: Termites
Ontario status: Not established in Ontario, warm-climate genus; occasional interceptions in imported furniture or lumber; reference species

Why it matters

Not an Ontario problem, but the classic exam contrast: the termite that breaks every subterranean rule, no mud tubes, no soil, no moisture dependence. Frequently intercepted in imported furniture.

Origin

Warm regions worldwide, the southern US, the tropics, and subtropics. The genus Incisitermes is most diverse in the Americas.

Behavior

Colonies are small (a few thousand at most) and cryptic; a single piece of furniture can house a whole colony. Swarmers emerge on warm evenings, often in late summer and fall.

Living conditions

Lives entirely inside dry wood, furniture, hardwood floors, window frames, structural timbers, with no contact with soil. Gets all its moisture from the wood itself and metabolic water.

Signs of presence

Tiny hexagonal frass pellets (like miniature barrels) piling below kick-out holes in wood
Small round kick-out holes (~1 mm) in wood surfaces
Shed wings on windowsills after evening swarms
Hollow blistered wood surfaces

Weaknesses

Small colonies, eliminating one piece of infested wood can eliminate the colony
Cannot survive prolonged freezing; cold is lethal
Frass pellets are diagnostic and betray the colony's location

Myths and facts

Myth All termites come from the ground.
Reality Drywood termites never touch soil. Finding no mud tubes does not rule out termites.

Research notes

Morphology

Pseudergates pale, ~10-12 mm; soldiers with large darkened, plug-shaped (phragmotic) heads used to block gallery entrances. Alates ~12 mm with smoky wings. Frass pellets are distinctively hexagonal in cross-section with six flattened sides.

Diagnostics

Hexagonal frass pellets are diagnostic at the genus/family level. Kick-out holes ~1 mm. Soldier head plug-shape confirms Kalotermitidae.

Easily confused with

Powderpost beetle, Lyctus spp. Beetle frass is fine flour-like powder, not hexagonal pellets; beetle exit holes are round and clean-cut.

Life cycle

Adult: Alates swarm seasonally; soldiers are terminal
Egg: Laid in batches within galleries; ~1 mm
Egg to adult: Often 1-2 years to produce alates; colonies grow slowly
Generations per year: Colonies persist many years; a few thousand individuals at maturity
Nymph or larva: Pseudergates perform all colony labor and may differentiate into soldiers or neotenics

Development

Hemimetabolous; pseudergates are developmentally flexible immatures, not a terminal sterile caste.

Reproduction

Low fecundity relative to subterranean termites, small colonies founded by a single pair; growth is slow.

Distribution

Global: Tropical and subtropical regions worldwide
Native range: Warm Americas; Incisitermes minor is the western US structural species, I. snyderi southeastern
Ontario: Not established; interceptions in imported wood products only

Ecology

Extracts metabolic water from dry wood; tolerates wood moisture as low as ~10%. Gut symbionts digest cellulose. Limited dispersal, colonies stay within one wood member for years.

Resistance

Unknown, no significant documented resistance.

IPM implications

Biology implies localized treatment logic: the colony is confined to the infested wood member, so detection (frass, acoustic, thermal) defines the target precisely. Whole-structure approaches designed for subterranean foragers do not map onto this genus.

Chemical ecology

Limited trail pheromone use compared with subterranean termites (no foraging trails needed inside wood); soldier defensive secretions documented in Kalotermitidae.

Genetics and DNA

No reference genome for the structural pest species; a high-resolution assembly of congener Incisitermes schwarzi was published in the 2025 47-genome termite study.

Taxonomy

Order Blattodea, family Kalotermitidae (the drywood/wetwood termite family). No true worker caste, immatures serve as pseudergates (false workers) that can molt into soldiers or reproductives.

Open questions

Moisture thresholds for colony establishment in marginal climates; interception frequency in Canadian imports.

References

Bignell, D.E., Roisin, Y. & Lo, N. (eds.) (2011). Biology of Termites: A Modern Synthesis. Springer.