Bagworms

Asked May 10, 2017, 12:08 PM EDT

Hi. Last Spring I positively identified bagworms chewing my Leyland cypress trees. This Spring, what FUNGICIDE should I use to prevent or destroy these bagworms insects. What is timing in Baltimore county, lifecycle.

Baltimore County Maryland bagworms leyland cypress tree pests trees

6 Responses

Each bag that still remains on the trees over the winter can be full of eggs. If you only have a few, the simplest thing to do is pull them off by hand and drop them in a bucket of soapy water to kill them. Otherwise, you will need to apply an insecticide.

The following page from our website will tell you all about bagworm control: http://extension.umd.edu/hgic/bagworms-trees-and-shrubs

ECN

So just to be absolutely clear a Fungicide applied to the branches will not kill the bagworm larvae and is a waste of money.?

Insecticides like carbaryl, spinosad, B.T., acephate, will?

I have googled bagworms already and know the information of your url, so, a yes or no answer here. Thanks.

So just to be absolutely clear a Fungicide applied to the branches will not kill the bagworm larvae and is a waste of money.?
Plz just answer "yes" or "no."

Insecticides like carbaryl, spinosad, B.T., acephate, will?
Please just answer "yes" or "no"

Fungicides kill fungi, so NO.

If you pick off the bags now, you don't need to treat at all.

As much as you want a yes/no answer on insecticides, it isn't possible.

Bacillus thuringiensis, often called B.t., is effective and non toxic but only works on small caterpillars, so B.t. must be applied between mid-June and mid-July.

If you miss those windows, after July 15th, use Spinosad.


cm





Thanks. I removed just a few bags.. but in doing some research looks more like a fungus, canker? Some pics included.
The tree trunk has holes around it. I have observed over the years sap oozing on the trunks. Any idea?
Treatment?

Thanks

The first photo shows symptoms of Seiridium canker, a common fungal disease of Leyland cypresses. The first symptoms of this disease usually appear in the spring or early summer, as a fading or yellowing of the foliage on branches, or the tops of trees. These symptoms gradually lead to browning of affected parts.


Management:
There are no chemical controls for this disease. The best strategies for prevention are avoiding stresses to the plants. Provide adequate water during dry periods, avoid overcrowding of trees, and don't over mulch or plant too deeply.

Your second photo shows sapsucker damage. Here is a link to our page with information about sapsuckers: https://extension.umd.edu/hgic/woodpeckers-and-sapsuckers.

CKC