Could be Sawfly Larvae. I've had them a few times and was able to just squish them (I know it sounds nasty) and get rid of them but if you have a lot you may need to spray. Maybe someone can comment on the best spray to use.

Laurie

Here is a link that might be useful: {{gwi:277135}}

Slugs/snails will leave the "see through" area on leaves you describe. I have a lot of slugs around here, but usually they don't bother my roses. However if they were confined to a container with nothing else to munch on, I'm sure they would do a number on them. As for cutting off the leaves the worms ate, outside of appearance, that really wasn't necessary. The more green foliage you have(even if it's tattered) the better. Powdery Mildew is something else. It usually attacks new, tender growth and some roses are more prone to it then others. You can do some things to curtail it culturally, but even if you do everything right, some roses will get it regardless. Here are some cultural hints on preventing P.M.: Good air circulation around the bushes is very important. Also make sure the roses are not allowed to dry out. In experiments, roses subjected to drought were more prone to attacks of P.M. There are spray materials you can use to help you with all of insect/fungus problems. It just depends on whether you care to use them.

For slugs try Sluggo. But in my experience slugs leave holes, not light spots. That sounds more like insect damage and for that you need an insecticide. You might want to try neem oil which is organic and will help with the mildew as well. Otherwise any rose spray will do the trick. Get the pre-mixed kind in a spray bottle.

I've got a lot of that, too, but can't spot the caterpillars or slugs in order to squish them. So I'll trust the above poster and leave the holey leaves on to make what food they can. ;o) Maybe if I find it becoming more of a problem, I'll try the neem oil. Will this ever be a devastating problem?

I found them! They are little tiny green worms! They have eaten the top layer of leaf, which leaves the skin I guess! Not sure what kind of spray to use. Thank you all for your input!

I tried last year a spray for catterpillars - doesn't work on these guys. I got rid of them this year though with Orthene. This hungry creatures ate most of the leaves on my minis :( Not much fun to see only flowers with skeletons of branches. It's been about three weeks by now and my roses are recovering very fast.