Web worms

Asked July 26, 2016, 11:51 AM EDT

I have 3 large healthy Norwegian Spruce and just recently noticed that the greens on some branches were being eaten. Upon closer inspection, I then discovered a small section has webworms. I pulled off as many as possible on the lower branches, but I am sure there are some above that I could not reach. In addition, I read online, after I pulled them off, that you should not pull them off, but cut them off?? I also read online that webworm problems should not be treated at this time of year....just in May, or early Fall? Since the web is not always reliable, I feel compelled to ask you. Can a call a landscape service to spray these trees now, or do I wait? Thank you very much.

Baltimore County Maryland

8 Responses

Please send us digital photos so we can see what you may be dealing with. Send photos of the whole tree, around the base, and affected foliage and insect pests.

If you need one of the whole tree, I will send more separately

Let me know if the photos I sent are enough.

We see a bagworm in the center photo and suspect that is what your trees are infested with.

Here is our website's info on bagworm control: http://extension.umd.edu/hgic/bagworms-trees-and-shrubs

When hand picking bagworms, you do not need to cut them off, put do not throw the bags on the ground. They will continue their life cycle. Drop the bags in a bucket with soapy water and let them die.

Get your trees as clean of bagworms as you can, then spray next spring according to our website directions if you think that is necessary. Hiring a company will be expensive and if you can remove the bags, spraying will not be necessary. However, always keep an eye on evergreens, because bagworms can crawl in from somewhere else. You do not want them to get established and do a lot of damage before you notice them.


I understand all that you said, and I did go to your link...however...some of the bags are too high up for me to reach. My trees are quite tall. Since I cannot pull them off, is it worthwhile, or adviseable to have someone spray them now? Will that kill the larva....or do I just let things happen to my poor tree and wait until Spring?

You can still hire someone who can spray with an insecticide that will effectively kill the bagworms. If you wait until spring to spray Bt, your trees will sustain some feeding damage this summer. The amount will depend upon how many bagworms you see. We cannot say from the photos, so it is your call.


Thank you!