Actually got a pic---not a great one as I took it with my phone as the sun was going down. Now I'm wondering if it's thrips?

According to people around here, aphids don't do any damage. ;-)

It could be both - you could have thrips and not see them ... you'll never see them until/unless the bud opens. They will definitely keep buds from opening if bad enough. Aphids will, too, but I think the bud and upper part of the stem would have to be almost covered up with them to do that.

I prefer spinosad (Fertilome Bagworm..., or Captain Jack's brands, for instance). It's very toxic to bees when wet, but it dries quickly and you can do all you can to make sure that bees don't land on the rose while it dries. It spares most beneficial insects, and that's why I like it.

Use it after dusk, when the bees are in for the night. Pull off any blooms nearby that are attractive to bees. If your blooms aren't opening, then spray just the buds, not all the foliage. Cut off any open blooms, though, unless you're sure no bees are flying.

After it's dry, the bees can come and they won't die. I use it sparingly myself and my yard is crazy with bees :) I wouldn't have it any other way.

Eta: I keep forgetting to mention that leafcutter bees seem different. If you have telltale leafcutter-bee circles on your foliage ever, rethink using spinosad there. You didn't mention circles cut out of your foliage, but I do want to note that in general :)

This post was edited by meredith_e on Thu, Jul 4, 13 at 22:53

Aphids are sucking insects so you won't see any holes anywhere. if you have a severe enough infestation, they can suck enough sap from the plant to prevent buds from opening. Aphids can be easily controlled with a spray from a water wand. You don't need an insecticide.

Thrips are another possibility and since many of them are very small, , they maybe difficult to see on the plant with the naked eye.

To check for thrips, hold a sheet of stiff white cardboard under the damaged bloom or bud and tap the bloom smartly against the cardboard. If you see tiny creatures moving about on the cardboard, you probably have thrips. We use a white cardboard artist palette that we got at a craft store.

Thrips are not easy to control and the control depends to a large extent on where you are located, because different species are prevalent in different locales. This is one situation where I would suggest you contact your County Ag Extension to get the recommendations for your specific area.

The link is probably more information than you need.

Here is a link that might be useful: Pest Thrips of the United States:

It looks like outer petals are rotting and turning brown. This would probably be botrytis fungus, which spreads in the cool rain. It commonly keeps buds from opening, whereas I have never seen aphids keep buds from opening, and I've watched aphids on roses for 37 years. If you peel off the outer petals, the bud may open.

michaelg:

Yes I have seen buds become deformed and not open under heavy pressure from aphids

To quote from Dale Ericson's ARS article on aphids

"Although healthy plants can usually tolerate fairly high populations without much effect, aphids are extremely prolific and populations can quickly build up to damaging numbers during the growing season. Then flower quality and quantity are reduced and the buds are usually deformed and fail to open properly."

Here is a link that might be useful: Aphids

I was thinking thrips, so you should check and make sure that you see thrips (with that paper test) before you use any spinosad. I hadn't thought of botrytis with your pic, but it's not a great pic, lol. Botrytis will keep buds from opening, yeah, and no insecticide will help that.

What MichaelG said -- looks like botrytis to me, a fungus we get with damp weather. Also could be thrips.

Sunny, dry weather should take care of the botrytis, if you can wait.

I just smash aphids with gloved fingers when I see them. A soapy spray can help too, but In my experience, regular insecticides cause more problems than they cure.

Here is a link that might be useful: Photos of Rose Pests and Diseases