The worms are here, the worms are here …

The worms are here, the worms are here …

Photo by: Eric Siegmund

Well, they really aren’t worms, they are caterpillars of the adult moth, the Oak Leaf Roller. The moth is about 1/2 inch long and has brown wings and brown markings.

In May, the moths lay their eggs on Texas Live Oaks. The eggs stay there for an amazingly long 10 months, until they begin to hatch in mid-March. And they are here. Now. I had my first sighting in the back yard moments ago as I almost walked right into one dangling from an oak tree in the back yard.
And they do dangle — down from the oak trees by the gazillions (well, maybe a few less than that) and make it almost impossible to pass under an oak without having green, squishy, squirmy caterpillars in your hair, and on your clothes, and everywhere you can imagine. These little caterpillars feed on the tender new Spring growth of the oak trees through late April. They can literally defoliate an entire tree. But they are a sight to behold if stand a little to the side of them!
Then they form the pupae stage and in early May, and the moths come out and then they start laying eggs again and the whole cycle starts all over again.
While you can control them with BT, or Bacillus Thuringiensis, we’ve never really needed to use it. The oaks are hearty, and while I’m sure they don’t like being eaten on, they bounce right back for the most part, so we just watch where we walk for a month and leave the moths alone to complete their life cycle. It’s another part of Spring, much like the flowering of daffodils, quince and Texas bluebonnets.
Then there is the new oak growth and the neon-green, powdery pollen that covers everything in a thick blanket of green dust … but that’s another post!

No Comments

  1. Carol March 29, 2008 at 9:41 pm - Reply

    Very helpful to know about these caterpillars before I innocently walk under a live oak. I sure hope if some “Austin-ians” see me heading toward a tree with a bunch of “worms” dangling from it, they stop me!

    Carol, May Dreams Gardens

  2. Lisa at Greenbow March 30, 2008 at 4:23 am - Reply

    This looks like an early summer photo Diana. I hate to say it but I am looking forward to seeing some bugs, even caterpillars.

  3. Michelle March 30, 2008 at 4:26 am - Reply

    I know. I know I should love all creatures big and small. But worms???? Walking under the oak trees only to feel something moving in your hair totally freaks me out (to say the least). That’s almost as fun as mowing and driving into a spider web!! I just visited your blog for the first time and am enjoying your writing style. I hope you don’t mind if I add a link to your blog from mine. Have a wonderful Sunday!

  4. Lori March 30, 2008 at 5:24 am - Reply


    I remember the first time I encountered these while on a walk. I was right in the middle of a dangling sticky grove of them before I realized, and then it was like Frodo stuck in Shelob’s web trying to get out alive, or at least with my dignity intact.


  5. Diana March 30, 2008 at 7:43 am - Reply

    Carol – We will definitely warn you! They really aren’t that bad unless you are in a grove of trees! It’s just another sign of Spring around here.

    Lisa – I can certainly understand that. During my 4 years in Minnesota, I just wanted to see a blade of grass or smell dirt while waiting for Spring.

    Michelle – welcome. Glad you found me and enjoyed my blog. I know what you mean – there are some creatures I just can’t stand… fire ants…grubs…too many to list here. I will come check out your blog later today. Hope you come back.

    Lori –I love the Frodo analogy! That’s a great comparison. Eeeww. I’ve become very adept at avoiding them when working under my oaks in the garden. I can spot ’em a mile away!

  6. mss @ Zanthan Gardens March 30, 2008 at 8:18 am - Reply

    I always thought they were spring cankerworms,Paleacrata vernata. (This is why I need to take the Master Gardener’s class.)

    Maybe we have different caterpillars but the problems sound the same. I battle them every spring when the cedar elms leaf out. They love the roses.

  7. Pam/Digging March 30, 2008 at 9:27 am - Reply

    Oh no, not the worms! Actually, with nary a live oak or red oak in my garden (only a young bur oak), I don’t have problems with these caterpillars. Soon though I’ll have another type that wants to munch up my Texas mountain laurel, redbud, Mexican plum, and flameleaf sumac leaves. In the past I’ve hand-picked them off, but my trees are too tall for that now. I guess they’ll survive the loss of some leaves, but those bagworms sure do look ugly.

  8. Diana March 30, 2008 at 12:20 pm - Reply

    MSS – Do you have to treat them, or do you just endure them? We have a few elms, but our problem is in the Live Oaks for sure. I’ve never had anything in my elms. Isn’t that funny? How different the environments and soil and critters can be in our gardens in the same city.

    Pam – I do get different caterpillars in my Mountain laurels – later on – and I do actually treat them because they will devour an entire small tree. I forgot which ones those are – I think they are actually a butterfly caterpillar – guess I’ll go do a little research and see what I find out. And I don’t have bagworms either. I’m lucky on that one.

  9. Annie in Austin March 30, 2008 at 6:33 pm - Reply

    There seems to be one kind of worm that appears on the live oaks, some kind of webworm usually comes to disfigure our pecans and a third kind will go after the Texas Mountain laurel shoots. Sometimes there are inchworms, too.


    Carol, BTW, the official name is Austinite rather than Austinian. Just reporting here… I don’t make the rules ;-]

    Annie at the Transplantable Rose

  10. Diana March 30, 2008 at 6:49 pm - Reply

    Annie – I don’t have any Pecan trees, so I am at least spared those! And then there are my grubs … don’t even get me started on THOSE!

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