Tent Caterpillar
Malacosoma americanum
low risk
insect
Overview
Early spring caterpillar that builds silken tent nests in tree crotches. Population cycles of outbreak and collapse. Rarely kills trees.
Caterpillars 50mm, blue-black with white stripe and colored side spots. Silken tents in branch crotches of trees.
Prevention Strategies
- •Remove egg masses in fall-winter (shiny brown foam on twigs)
- •Prune out tents when small
- •Monitor in early spring on susceptible trees
Control Methods
- •Prune out tents when small in early morning or evening when caterpillars inside
- •Bacillus thuringiensis (Bt) when larvae small
- •Twist stick into web and pull out while wearing gloves
- •Pyrethrin spray into web opening
Interesting Facts
- •Populations go through boom and bust cycles roughly every 10 years
- •The silk tent serves as a solar collector warming caterpillars on cool spring mornings
- •Eastern tent caterpillar and forest tent caterpillar are different species (forest tent has no tent)
- •Trees almost always fully recover from defoliation