I have no idea what they are, but, yes, spraying with horticultural oil would probably get them, as would spraying with neem extract. If they're some type of true caterpillar, such as tent caterpillars, a Bt spray will also get rid of them. As to when to spray the canes, always spray them as you spray the foliage.

Thank you Field, you are always so helpful.

Rose

If the green worms sort of curl up than you have rose sawfly larvae, which are a problem here. These aren't catapillars and don't respond to Bt.

I hand pick them and squish them which is tedious.

Field, I am curious about Neem because I've heard it used for japanese beetles as well, but have been hesitant to try it for anything because I thought it was a non-selective insecticide that will kill beneficial insects like bees and ladybugs too?

Any oil spray is nonselective. But neem isn't otherwise toxic to bees. In fact, I've read that it's used to fight the mite that is killing honey bees all over the country.

I wouldn't recommend it for killing Japanese beetles; the research doesn't support it. A paper by Harper and Potter (1994) found it repellent to Japanese beetles in lab tests but ineffective on crabapples in replicated field trials. A study found that commercial neem, pyrethrum, garlic, cayenne pepper extracts were also ineffective (on birch) (Witt et al. 1999).
You may want to post this on the IPM and Garden Clinic sections; that's where a lot us entomologists, plant pathologists lurk.

Regards,
Colin

I don't know what your tiny green worms are. Ours are from a white moth. I used to handpick the worms but this past summer I decided I no longer wanted to kill worms. I've been encouraging more birds to visit the garden and looked out one day to see some Ruby-Crowned Kinglets patiently going through the rose bushes eating the little worms. I'm sure they missed some as there were a few lacey leaves on the bushes, but I thought the Kinglets did a fine job.

Today for the first time, I saw a number of tiny green caterpillars(?) on several rose bushes. The first thing I noticed was a rolled up leaf that was slimy inside. Then I started seeing several skinny creatures that are about 1/2 to 3/4" long, with a black head. When I tried to pick them off by hand they quickly wiggle and drop down to another leaf. Does this sound like an identifiable pest?
Thx,
Valentine

Sounds like rose slug larvae to me, valentine. Refer to above postings for treatment. They will turn your foliage to lace if you let them.

I have them too and have never had them before..What's w/this? Is this a "special" year why so many people are getting them? I've been squishing them every am and pm. I think I finally have them all. I have also seen a beautiful catepillar that is black/white on top and blue on the sides and head. Really pretty thing..I left him there. I have 3 of those guys. Anyone know what these are? Anyway, I tend to just water spray and sqish as I have so many birds that I'm hoping they discover all the wildlife on the foliage. I stop feeding in the summer to encourage them to forage..
Hilary

The #1 best controller of rose slug (sawfly larvae) and nearly all other rose defoliating caterpillars, IMO, are Wasps.

The past 3 years I've been watching wasps "patrol" my roses, it's an amazing thing to see, they check below every leafset for larvae to pluck off and take back to their paper nests.

One year we had tons of wasps, then the neighbors killed a large nest in their grill. The next year there were few wasps and I ended up patroling the roses myself every day.
Those few wasps worked on building 2 nests on our house all last year, not very large nests, but I'm confident that their numbers this year will be enough to control the crawlies again.

Free, easy, harmless and fascinating to watch.

Those little green worms sound like sawfly larve, what are commonly called "rose slugs".

BT does not work on them because they are not truely worms. The only spray I have found to work is neem oil sprayed on the underside of the roses weekly.

However, I have close to 100 rose bushes and the only ones that I have a problem with the rose slugs are the ones close to the house in my courtyard... where there are no birdfeeders. The roses in my garden in back where all the birds live are perfect! Not a holey leaf in sight.

The other day when I was taking a break from working in the garden, I was sitting quietly and I watched a hummingbird go over a rose bush and flip through all the leaves with his beak, I assume looking for bugs... and maybe finding a few rose slugs!

Of course I have put a bird feeder out in my front courtyard, but the birds haven't found it yet. I may have to leave a seed trail!

I should have been more specific about Wasps, since many people confuse them with aggressive Yellowjackets and Hornets.

Here are photos of Paper Wasps and their nests... If you want organic Roses, don't destroy these nests on your house.
Of course, if a nest is being started too close to a busy doorway, it would be in the Wasps best intrest to knock it down to encourage them to biuld elsewhere. They can live nicely in a high traffic area without attacking people, but most people don't know or believe that... No wasps will take kindly to being swatted at by ignorant strangers on your porch.

Here is a link that might be useful: Paper Wasp pics

I'm glad to know what these guys are. My back door is surrounded by them. I have one on each corner of the porch, on the eaves by my bedroom french door and around front. I had them last year and the nest was huge. People would go out the door, look up and dash back in the kitchen. I told them, they don't bite. They looked at me like I was crazy. But I sit 3' below them in the morning and have hot tea, they fly right in front of my face, and then buzz on. If it doesn't bother me, then I figure it's part of the whole scheme and leave it be. So far, so good..Hope I haven't jinxed myself. LOL
Hilary PS. I thought they were just nectar eaters, I didn't realize they ate bugs..

Well I've got em too and they're really starting to torque me off! I just go around now and squish those folded leaves and blast the roses with the water hose. AARRGGHHH!

Now, Hilary, you can continue to feed your birds if your feeding seeds and not meal worms as most birds that eat seeds don't eat bugs. ex: wrens and blue birds eat nothing but bugs. Cardinals and finches eat seeds only. Jays and mocking birds and others will eat both.

As for hummers eating inscets, yes they do, but it's been taught to me that they only eat bugs that they "catch on the fly" as they have no way to swallow them unless the bug is caught almost in the throat. But, I'm not a fanatic about that idea and if he's rummaging around in your roses, then I hope to goodness he's chowing down on worms!

Luck to all
Moo