Eastern Tent Caterpillar (Malacosoma americanum)
GDD Window (base 50): 90-190
Overview:
- Overwinter as eggs, black masses that wrap around small twigs of host plants and hatch in the early spring, using web tents in the forks and crotches of branches as protection and feeding on leaves
- Young caterpillars are dark with two thin yellow stripes on backs
- Mature caterpillars are two inches long with a white stripe and two yellow stripes on their backs, the rest of their body being blue, yellow, and black
- Cocoons are white to yellowish and are spun in dry, protected places
- Adult moths are fluffy, tan to light brown, with two white stripes on the wings
- Can cause complete defoliation, consuming all fresh buds and leaves
- Host plants: Rosaceous trees – cherry, crabapple, apple
- Occasionally other deciduous shrubs and trees
Management:
Cultural Practices:
- Natural predators: many birds, insects, and parasitoids
- Prune out egg masses in the winter before they hatch
- Remove silk tents using a disposable object
- Do not use fire – fire will cause more damage to the tree than the insect itself
Materials:
- Contact insecticides:
- Carbamates [1A]: carbaryl
- Pyrethroids [3]: –thrins
- Systemic insecticides:
- Organophosphates [1B]: acephate
- Considerations:
- Will harm non-target species
Biorationals:
- Horticultural oil
- Insecticidal soap
- Spinosyns [5]: spinosad
- Microbial disruptors of insect midgut [11]: Bacillus thuringiensis (Bt)
Disclaimer – Materials do not cover all possible control scenarios and are intended for licensed professionals. Tradenames do not imply endorsement and are used as examples. You must strictly follow the label for each compound prior to use. Rutgers is not responsible form is used materials or damages thereof. The label is the law. Labels will provide detailed information on use and restrictions. Additionally, application intervals, compatibility, surfactant use, PHI, PPE, important and other key information is described in detail. Always discuss treatments with your local agents. Note: Neonicotinoids can only be legally applied in commercial agriculture settings by licensed applicators. Guidelines and recommendations made in this presentation are specific to the state of New Jersey.