You can spray a highly selective bio poison--Bacillus thuringensis, also know as BT. Most organic gardeners consider this an acceptable solution. But, it is so selective that it doesn't touch rose sawfly--though it is deadly to many caterpillars.

This is another example of how ineffective the soil-drench insecticide is. The Merit ingredient encourages spider mites without actually eliminating insect problems.

If they are true caterpillars, BT (bacillus thuringensis) is the ideal remedy. If they are sawfly larvae, the best option is spinosad, which also controls caterpillars and is relatively benign. Read labels for active ingredients. If you only have, say, 20 roses, hand picking should be effective and easy.

If they are sawfly larvae, just wipe them off the leaf and toss them in the grass. They will never make it back to the rose, and in a couple weeks, the good bugs will be there and kill any remaining sawfly larve on your roses.

The sawfly larvae look like tiny green caterpillars, though they aren't really caterpillars, and sometimes they are very hard to see on the back of the leaf or curling along the leaf edge or around the bud. I usually have to spend about a week disposing of them as I described above. Then Nature comes along and takes over the job for me.

Kate

Thanks for all of the tips.
I went out this morning to pick and found the same pillar in 3 different stages. The first was about 1/2 inch long green with faint yellow stripes, the second about 3/4" with more prominent stripes and the third about an inch, really fat, to the point of looking white with green undertones with a horn like protrusion on its tail. Not sharp, just a fleshy bump.
So, not sure what they are, but don't think they are saw flies, so will try some Bt.

They have eaten 90% of the buds on my Lady Banks. I threw the little suckers on the driveway for the hungry birds to feed to their young. Reduce, reuse, recycle!

The other roses that I treated with the Bayer, did not have any worms on them this morning, so maybe it is finally kicking in.

There are many different sawfly larvae and they look like caterpillars. Some do attack rosebuds. I would go with spinosad unless you want to learn how to distinguish them from caterpillars.

http://www.google.com/images?client=safari&rls=en&q=sawfly+larvae&oe=UTF-8&um=1&ie=UTF-8&source=univ&ei=1R3LS_z6F5SY8QSIi8nDBA&sa=X&oi=image_result_group&ct=title&resnum=1&ved=0CA8QsAQwAA

Sorry, forgot how to link here.

Here is a link that might be useful: larvae pictures

HMM, I saw damage like that on leaves and a bud of my Mr. Lincoln. I will check for saw fly larve and I do have spinosad.

digridge, we are not talking about saw flies. We are talking about the LARVAE of saw flies. The larvae look like mini caterpillars, but they are larvae, not caterpillars. Just wanted to make sure we are all talking about the same thing. : )

Since it is very easy to take care of the larvae of saw flies without resorting to insecticides, I'm not sure why some posters are so eager to use insecticides. If you handle the problem manually for about a week, the good bugs will arrive and finish the job for you. Wish I could remember what the name of the good bug is that attacks the larvae of sawflies, but I don't. However, the good helper bugs are on their way probably right now. If you use the insecticide, you will probably also kill the good bugs--which means, of course, that they won't help you out.

I'm serious about this. I go through it every spring.

Kate

Typically, in my garden, the sheer number of sawfly larvae is astounding! They deface markedly, nearly every leaf on some plants. I have not suffered bloom damage but, rather, the gnawing away of segments of the leaf...usually with a membrane uneaten while the larvae are small but the older larva eat membrane and all. The sawfly larvae are usually referred to as "rose slugs", while they are not slugs or caterpillars at all. For identification, I have attached a couple of photos of the larvae in my garden.

Bob

Typical damage.
{{gwi:246025}}

The underside showing the presence, usually one per leaf.
{{gwi:246028}}

Close-up view.
{{gwi:246032}}

thanks Bob!
I think mine were some sort of sawfly larvae. Fortunately, they have gone now, but not before eating all but 4 of my Lady Banks rose buds.
I'll have to keep an eye out for them next season and pick them off before they decimate the buds

I went out this morning to pick and found the same pillar in 3 different stages. The first was about 1/2 inch long green with faint yellow stripes, the second about 3/4" with more prominent stripes and the third about an inch, really fat, to the point of looking white with green undertones with a horn like protrusion on its tail. Not sharp, just a fleshy bump.
So, not sure what they are, but don't think they are saw flies, so will try some Bt.

Sawflies do superficially resemble caterpillars, but if there was a horn-like protrusion curving up and backwards from the back end of the critter that was no sawfly. That was the caterpillar of some sort of hawk moth (hawk moth family = "Sphingidae"). Hawk moth caterpillars are the only insects with that particular anatomical feature.

The one most American gardeners are probably familiar with is the {{gwi:246022}}, but there are other hawk moths that are a lot smaller than this. (This one is one of the bigger ones.)

this is good post as i was wondering what those 'pillars'/ larvae were. my viking queen is a magnet for these little buggers; it is the only rose that they really target.
same place too; right along the bud underside rolled up in a leaf. i pick them off by hand.