Bagworms can be found all around the world. They may go unnoticed when they first arrive but within a short period of time they can multiply to huge numbers. Bagworm damage is easy to spot and if not controlled will cause plant and tree death. For this reason bagworms are a nuisance pest and one that needs treatment if you find them active.
Bagworms eat plant and tree leaves and can cause substantial damage if left alone. They love most any arborvitae but will also eat maple, boxelder, willow, black locust, poplar, oak, apple, cherry, persimmon and just about anything with green leafy leaves. For this reason it’s important that local activity is duly noted.
Failure to deal with inital stages will mean more will soon arrive. It’s much easier to treat one or two females early in the growing season and stop them before they populate. Since each female will lay 500-1000 eggs, a couple can turn into many thousand within a year!!
Bagworm control is easy to do and maintain since they are easy to kill. The key is early detection and early treatment.
If you’ve identified activity, treat as much of the plant or tree as well as the surrounding foliage of other plants. This insures you get them all. A good and thorough application in the spring can many times keep local populations in check.
However, if you find a large infestation later in the year, treat once every two weeks till you don’t see anymore. Late season applications won’t have nearly the affect of early spring time treatments for two reasons.
First, the young larva are much more susceptible in the spring and weak so chemical treatments work better. Treating later in the season when bagworms have reached maturity means you’re dealing with a stronger pest.
Secondly, the pupae stage of bagworms is not susceptible to the treatment. Their cocoon will protect them from chemical applications and only when they hatch out can they be affected. For this reason it’s important that you do multiple applications when treating late in the year. Repeat treatments assures you’ll have good protection to get each release of female and male pupae from their bags.