Bag Worms!

[Wysteria626]

I have a tree-lined property with 100 arbor vitae trees about 15-20 feet tall. Some have developed a horrible bagworm infestation. Being on a well, I cannot spray the trees because my well cannot meet the water demand and the pump cannot supply the pressure. I have two estimates from arborists. The first guy will spray now, in the fall, and next May for $1500 (US). I have to confirm, but I believe he will spray the trees (for worms) and the ground (for eggs). The second guy will only spray once (now) and says the runoff will treat the ground for only $800 (US). Are three treatments really needed? On the one hand, I don't want to throw my money away on three treatments if excessive; however, I don't want to throw away $800 for nothing if the second guy is over-simplifying the problem.

Also, although I am on a corner lot in a neighborhood, what (in general) is the best way to deal with my neighbor? Only spray inside my tree line on his side? And/or, at least let him know when I'll be spraying and/or would he mind me spraying on his side?

Last, how long before it is safe for kids and pets to access the area? FYI: The first guy may use Talstar Professional insecticide or Mavrik Perimeter (I will have to confirm)). The second guy will use Sevin.

All advice welcomed!
-Wysteria

 

[oneeye]

Sprays are ineffective once the bags are built and the caterpillars full-sized. The most effective time to spray is June, shortly after the eggs have hatched and before the new crop of bagworms has had time to build their protective cases. Timing is crucial for the sprays to be effective.

Male bagworms fly from their cases in September through early October to mate with females in their cases. Then both die off, leaving behind anywhere from 500 to 1,000 eggs per case. Those overwinter on the plants, and the eggs hatch the following May through early June.

Picking as many bags as you can is the best thing you can do. If you can see them, then everyone you get, and pull off the tree will save you from getting 500 to 1000 eggs next year per bag. If you have children or grandchildren pay them a dime for every bag they pick, just be very careful and don't fall off the ladder. Dispose of the bags in plastic bag and send to the landfill. .

 

[Sheal]

Take a look at this thread @Wysteria626, you might find it helpful.

Bagworms

My son's shrubs are being invaded by Bagworms. Can anyone explain to me what they are please and how to get rid of them?

www.gardening-forums.com

 

[Wysteria626]

Thanks for the link. I read through all the comments. Many say nothing can be done (by pesticide), and it seems the assumption is the pesticide will not penetrate the bag of the bagworm. However, the worms feed on the leaves. Surely, spraying the leaves with recommended insecticides (from other sources) would poison their food source.

 

[Sheal]

Surely, spraying the leaves with recommended insecticides (from other sources) would poison their food source.

I don't know whether that would be effective. Unfortunately living here in Britain I don't know a great deal about bagworms or the insecticides you use in America. Any knowledge I have has been supplied kindly by Chuck here, or from the internet as we don't have this particular pest here.