Forest Tent Caterpillar

Tent caterpillars appear to be problematic in Airdrie and many other communities across the Prairies.

The larvae of Forest Tent Caterpillars are identified by blue strips down their backs with small white key hole shaped markings. They congregate in tents made of their own silk every night.

Forest tent caterpillars are problematic as they affect any broadleaf plant and will completely defoliate a tree.

The City of Airdrie is monitoring and controlling trees on City owned property but you can help us out by reporting any sightings of Forest Tent Caterpillars in the parks or green spaces in and or around the city to the Parks department at 403.948.8400.

If you find large numbers of Forest Tent Caterpillars on your private property, they can be controlled by removing the mass of them when they are all together at night and stepping on them or squishing them with something or by spraying them with BTK (an insecticide containing Bacillus thurengiensis) which can be found at most home stores in Airdrie.

This is what they may look like at various states:


Egg mass 

Larvae (caterpillar stage)

Tent Caterpillar

Pupa (cocoon stage)


Urban forest

Trees are a community asset and an important part of a community’s image, identity and well-being.

The City of Airdrie encourages the expansion and preservation of City trees as outlined in our Urban Forest Policy. Recognizing that all street trees have a life expectancy and will eventually need to be removed and replaced. Trees will only be removed when specific criteria are met.


Tree & Shrub Planting

The City of Airdrie plants replacement trees and shrubs in and around the City on a yearly basis.

Parks staff will looking after the in house planting which consists of planting small trees and shrubs while the larger tree planting requires this work to be contracted out, this is referred to as the contractor planting.


Contact us


P. 403.948.8400

F. 403.948.8403