From the Merry Oaks neighborhood Google group:
"I live on Cosby Place; We still have lots of worms in this neighborhood; we banded, then the spraying. Does anyone else still have
"Yes, but not as much as last year...Our street tree leaves are about 1/4
eaten instead of 3/4 eaten."
"Yes. I live in Commonwealth Park - they aren't nearly as bad as last year but I have noticed more and more each day. They are definitely in one of my huge oaks and now that the flowers have dropped off my dogwoods (2 very large dogwoods), I'll be keeping an eye on them too. I'm debating calling Barlett Tree to come spray but I just don't have the $$. I even double banded some of my trees. Stupid worms."
"Canker worms hatch in cycles for about 3 weeks to a month. The city's spray killed the worms that were actively feeding at the time, but since it isn't systemic, it would have washed off in the next rain. I still have my Bug Barrier bands on my trees and added a little Tanglefoot to catch any of the little paratroopers once they started climbing back up (you can still get Tanglefoot from Black Hawk Hardware at Park Road Shopping Center).
"I'm not a big proponent of using chemicals, but if the worms have totally invaded your bushes, a quick spray with Raid yard fogger (for mosquitoes) will drop them in their tracks. I discovered that during the huge invasion a couple of years ago..the worms were annihilating my front bushes and I used the yard fogger..I was able to take out about a thousand of them in under 15 minutes. For trees, Home Depot also sells a solution that you can attach to your hose, but be very careful of overspray, dress appropriately when using it, and watch out for children and pets using the yard for a bit.
"Another option is to get an arborist to inject a systemic treatment directly into each tree's root system. It will make each leaf deadly to the worms when they try to feed, and lasts about a month.
Hope that helps!"
Photo courtesy of Flickr user xxxtoff of Winnipeg, Canada (where the worms live too). Shared under a Creative Commons license.