You may want to take a picture. However, if these are tiny green bugs on the new growth, they may be aphids. Those won't hurt your roses, more of an eyesore for us. You can just squish them :-)

Where are you located? Could you post a photo of the insects? Or a better description ("green bugs" is not very helpful)

if you do have aphids, depending on location and level of infestation, aphids can be a minor problem or a serious one.

I disagree that they can't hurt your roses - they can. (see photo)

However, they can be controlled without an insecticide.

Thank you for that photo nickl. Some years I have gotten aphids that badly and have been a bit puzzled by comments that aphids can't hurt your roses. What non insecticidal methods (aside from squishing) would you recommend?

I had a pretty bad infestation of aphids this spring and I didn't want to use insecticide, so I ordered 5,000 ladybugs and released them into my garden. Within a week, there wasn't an aphid to be seen. I've also heard that a hard spray of water can knock them off.
Maude

There is disagreement on this forum whether aphids are a serious threat or not. In either case, the predators of aphids will show up in a week or two and take care of most of the problem (ladybugs being a major predator, but I've also seen small birds chowing them down also). In the meantime, unless you are queasy, just gently run your fingers and thumb along the bud and stem--that will kill them.

Kate

If I had an infestation of aphids that thick, I would put my hand behind the affected growth, and blast it with water, while brushing at the little #@#$%#$##'s with water. That's enough to do the job.

I've actually seen a few aphids this year, for the first time in a long time. I haven't seen a heavy infestation of aphids like that, though, since I quit using pesticides in my garden. There are enough predators here to take care of them.

I think a heavy infestation of aphids (as shown) actually COULD do some damage -- but they're so easy to eliminate without chemical pesticides that it's simply not worth using them. The harm they do far outweighs the good they do.

Jeri

Jeri:

A good water spray - best with a water wand so you don't get soaked yourself - is the preferred control for aphids even for a small infestation. It's important to cover the top and bottom surfaces on the plant, hence the water wand.

The water spray will knock the aphids off the plant but still make live prey available as a meal for their predators, so the predator population can continue to build without having your roses subject to damage.

Not only do insecticides reduce the predator population directly, but they leave no live prey, so the prey-predator cycle has to start all over again.

Best with a water wand -- but of course, in SOME weather, getting soaking wet ain't such a bad deal. ;-)

Yuppers. Water's a fine "pest control" product.

Jeri :-)