Field guide to exotic pests and diseases: Black carpenter ant

Camponotus pennsylvanicus (De Geer)

Black carpenter ant worker

Black carpenter ant damage caused by ants constructing galleries

Identification: live in colonies, most prevalent are the workers which are black, reddish-black, 11-18mm long. Winged males and females produced early spring-midsummer, swarm in large numbers.

Hosts: nest in living and dead trees, rotting logs and stumps, buildings, wooden structures. Hard and softwoods may be attacked: infestations recorded from white and pitch pine, balsam, elm, hickory, juniper, aspen, oak, Douglas fir and western red cedar.

Distribution: USA, Canada (eastern and central states).

Detection:
Nests: in imported containers, in untreated imported timber and timber packaging and dunnage. Nests established in cavities in wood that has deteriorated or been exposed to moisture. Small piles of sawdust outside the colony entrance can indicate infestation. Galleries kept smooth and clean, not lined with moist soil (cf termite galleries).

Potential impact: can cause serious damage to timber in-service; undetected infestations can lead to failure in structures and other timbers.

Field guide disclaimer