Using Natural Insecticides
Spinosad
AzaMax will control Tent Caterpillars
AzaMax is a natural product with a broad spectrum of pest control and broad plant applications. AzaMax is an anti-feedant and insect growth regulator which control (kills) pests through starvation and growth disruption within two or three days. Therefore this product is used when the bugger is chomping on the foliage. Any of the sprayers can be used to apply AzaMax
For more information about AzaMax go to the Yardener's Tool Shed; click here
Bacillus Thuringiensis
Tent caterpillars are vulnerable to insecticides only while they are still moving around and eating leaves and other plant parts. Spray the affected plant thoroughly with a product containing the beneficial bacteria . Bacillus thuriengensis (BT) when the caterpillars are actively feeding. This will likely be sometime between March and April, depending on where you live. The caterpillars eat the Bt along with their usual leafy meal. When they ingest the bacteria, which harms only caterpillars, they sicken, stop eating, and die within a day or two.
For effective control you need to time the application fairly carefully. For best results, spray once and then repeat 10 to 14 days later. Spray initially in March or April , when the leaves are about half to three-quarters open. Because Bt washes off with rain, reapply it in 10 to 14 days to be sure you control the problem. Two sprays will generally be enough to keep the tree from being defoliated. Read and follow label instructions for use, storage, and disposal of this product, as with any other insecticide. If the tree or shrub is very tall and difficult to reach, hire a professional arborist to spray the tree properly and safely.