BT Worm Killer (Bacillus Thuringiensis) applied as a spray or powder ought to take care of them if they are caterpillars.

It is not toxic. It is a bacteria to which only caterpillars are subject.

Thanks, Roselee, whatever they are, they are near invisible as I still have not spotted one working.

Well, it might be some sort of little beetle, or the caterpillars are very good at hiding during the day. I'm not familiar with what bothers grapevines. Maybe someone else is.

Meant to say "Maybe someone else DOES."

Maybe bumping this up someone else will see it.

Here's a little something about grapevine leaf pests, but would be better if that 'someone' be from Texas and could give us a hint of what's likely to be on grapevines this time of year.

Here is a link that might be useful: Insect Pests of Grapevines

I don't know what your pest is, Carrie, but have you gone out there at night with a flashlight and looked really good, including (and especially) on the backs of the leaves? Many bugs and most caterpillars are much more active at night.

Are you near Austin? If you can't ID it, put some in a ziploc and bring it up to the Natural Gardener's info desk. They'll help you figure it out and tell you the least toxic way to get rid of them (sometimes that's with a dustbuster ~ just be sure to empty it before you bring it in the house *ACK*).

Hi Carrie, I think I remember there being a grapevine beetle that could also lay eggs and then you would have a caterpillar also, lol

Thanks, ALL, if I don't find out what it is before winter, maybe MN will kill it for me. Good idea, Knitllin, about taking a leaf in. I have a nursery friend who may be able to identify it for me as he lives near me. Unfortunately, I am not near Austin, but in North Texas .... grew up in that area and still miss it.

I sometimes see a moth caterpillar on the wild grapevines. The Eight-spotted Forester Moth. But you'd probably see those.

Here is a link that might be useful: Eight-spotted Forester Moth caterpillar

Oh, I definitely would have seen him....LOL, but thanks for the info. I do have wild grapvines in the donkey pen, and will watch for these guys.