I have what looks like a huge spider web on the entire truck of a very large oak tree and now is moving to the

Question

branches. I have seen web worms but have only seen them in the leaves of trees. Does anyone know what this could be?

Thanks Billy Ray - that sounds like it might be my problem. The web is one big web, not several, and not in the leaves - only the trunk and branches. And, yes I do live in the South - Texas. How would I treat this?

Answer 1

From your question, you don't appear to need a cure for this pest so, I will just tell you what I think it may be. It sounds like you may have "Tussock Moth Larvae", possibly the Western Tussock Moth.

After emerging from the over-wintering eggs and feeding during the spring, the larvae pupate on the bark of the trunk or main limbs. The western tussock moth usually only has one generation per year, but in southern California two generations may occur. The second generation larvae are present from about late August to October (which is now) and this is what leads me to believe, that this may be what you have. Normally you wouldn't see larvae at this time of year, they would have already pupated and over wintered until next spring. Do you live in So.Cal or a zone which is somewhat mild in the winter? If you do, this is what you more than likely have. If you would like to know how to get rid of them, update with additional info and I will be more than happy to give you my honest professional opinion. Usually there is no need to spray tussock moth larvae as the damage is mild compared to some caterpillar pests. Hope this answers your question.

Additional Info: If the web is low enough to spray yourself with a 1-gal sprayer or backpack sprayer, all you need to do is go to the nearest Walmart, Home Depot, or Lowes garden section and purchase one of two products. Liquid "Sevin" concentrate will do the trick pronto, as well as a product made by "Ortho" called.."Systemic Insect Killer". The Ortho product as stated is a systemic insecticide, so it will enter the foliage and protect up to about 3 weeks maybe 4. When the pest eats the foliage it ingests a chemical called "Orthene" also known as "acephate" and soon dies. It also kills by contact, so when the caterpillars are hit with the spray they will be dead within a couple hrs. "Sevin" is a little safer for the environment and I would recommend this over the Ortho product. Sevin is a contact insecticide and will do the job quite well. Make sure you try to do the job early in the morning when the sun starts to shine on the web. They will all be there sunning themselves and warming up before feeding and you can catch them all at the same time. If the web is too high for you to reach with a sprayer, you will have to call a commercial spray company to do the application for you. They usually can do it for a nominal fee. The price may be around $50.00 or so, not bad, if you don't want to be bothered with it. Good Luck!
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http://www.ortho.com/index.cfm/event/ProductGuide.product/documentId/72c90bb34e83ab40af12b25b1d77e798

**Billy Ray**

Answer 2

Please don't try to burn them in the tree! That would cause far more damage to the tree. If you can rip open the web and get it down, then burn it away from the tree, great.

There is an effective pesticide that is very enviromentally safe called Bacillus thuringensis kurstaki. BtK for short. It can be sprayed into the tree and paralyzes the caterpillars' stomach, they die of starvation. However, the product must be sprayed within the web where the foliage resides that the caterpillars eat.....and it can be sprayed outside too.........if the stuff lasted for more than a few days. So you need to break open the web or have an arborist with a high pressure or high velocity sprayer which can break the web apart. Also the chemcial needs to have a UV inhibitor in it....many now have it in.........and the chemical applied later in the day when the sun isn't as intense......dusk would be great. PHEW!

You might want to contact your Cooperative Extension Service agent for your county and see what is being recommended for your area.

Answer 3

And in the South we have what we call "tent moths" or caterpillars. Similar to gypsy moths, these especially like pecan trees, but attack others as well. What is attacking your oak tree is probably something like that.

Answer 4

In New England we have severe problems with gypsy moths and that's what your description sounds like. The only way to get rid of them is to take down the affected portions and burn them

Answer 5

These are called Bark Lice and they are beneficial to the tree - leave them alone - the clean the bark and then they will disappear. Be thankful you get them. I get them every year and welcome the little critters. Yes, they cover the complete trunk in on continuous web - ignore them and they will do their job and go away.
Flip
Manvel, TX.

Answer 6

www.ortho.com