Thank you for posting this.I have moved to an area infested with them.

they don' pull off easily

kinda cool how their camouflage looks different on different plants

KILL,,,ron

Good post. Don't miss a single one or you will have hell to pay the next year. A single bag left unchecked will overwinter 300-1000 eggs to hatch the next year.

I am currently fighting this war and it's not fun especially when you have a large yard. I meticulously hand picked them off of almost every tree in my yard last year. I hate squishing them but my chickens won't eat them =). I spent every day after work hunting them and I have developed quite the eagle eye now. I have found them feeding on everything from conifers to maples and just about anything that has leaves. When they spread, good luck on reaching them in high trees. That's the predicament I'm currently in.

last year I thought that I had got them all until I looked high into the large blue spruce in my yard. There were quite a few that I just could not reach with my ladder and sprayer. I'm screwed. The tree wasn't looking the best so I figured I would make the sacrifice, cut down the large tree, and burn it. Well, I'm a dumb ass and never got around to doing it and now I have 10 times as many bag worms as last year.

Dipel or Thuricide (not a chemical but a natural bacterium Bacillus thuringiensis or BT) must be ingested by the bag worms and is most effective on new larvae when they first emerge. They are more resilient when they get larger. Those silk bags are tough and protect them from everything including predators and insecticides. Quite a smart system they have going. =(

I thought I could save the big blue spruce by using a systemic approach with Imidacloprid that would be absorbed by the trees roots and then circulated into the leaves and needles which would be able to reach the bag worms up high. So far I have applied this once with no effect. All the bag worms are still munching away, moving about, and giggling at me. It has been a month since I treated the tree. I may go for another round and see what happens.

Sam, how did you take care of the ones you can't reach with the sprayer?

Sorry for the long rant. I'm just having a heck of a time.

When used on trees, it can take 30–60 days to reach the top (depending on the size and height) and enter the leaves in high enough quantities to be effective.

Quoted from https://en.wikipedia.org/wiki/Imidacloprid (scroll down the page)

Bagworm infestations are common in the wild here, we're loaded with native redcedar trees. The pests are cyclical, heavy infestations occur every 10-15 years, but they are present in various numbers every year. In heavy years large tree sized redcedars are mostly or completely defoliated and usually die. Leylands, which are commonly planted here are also attacked. I've never seen any on green giants, which are rapidly becoming the go-to tree for screening here. Fortunately they don't reach populations like gypsies and their tastes are much more restricted.

Sam, how did you take care of the ones you can't reach with a sprayer?

I leaned a step ladder into the tree and climbed up. This is a large, wide Hinoki Cypress w/o a central leader so it was precarious. I got them all but I know I will have to check again.

Previously I thought only the newly hatched caterpillars did the traveling, I think that is not entirely true. Here is one clinging to a wall no where close to a host plant. It is near a parking lot.