Whether they can or can't crawl back up, new crops of them hatch out all the time. Like aphids, Japanese, Fuller, Curculio and other beetles as well as all other insects which suck or chew the plants, you have to continually battle them during their "season" using whatever methods you've selected. I'm not recommending any method nor attempting to encourage you to go "nuclear" on them, but the less toxic your method, the more interactive you have to be with the control. With more generations regularly hatching from eggs, and more eggs being deposited as long as conditions favor their reproduction, new "slugs" are appearing daily or every few days. So, if you're knocking them off, picking them off or washing them off, you have to be diligent at it. Pick, knock or wash them off daily or every few days as your time, energy and infestation dictate. Or, go with an organic control like the bacterial Spinosad, which knocks down all of the hatched slugs at once for two weeks. That has to be sprayed twice monthly unless it's all washed off by a heavy rain. Yes, it can kill the predators, too, but all "insecticides" will. The point is, you have to determine whether you want to constantly battle them or take stronger measures against them. They not only cause unsightly damage, but ANYTHING which reduces the green leaf area of the rose, inhibits, reduces its ability to feed itself. Reduce the leaf surface area sufficiently and you inhibit the plant's immune system, weaken the plant,by causing it be malnourished, making it more susceptible to other damaging factors such as fungal attacks and potential freeze damage in winter, if that is a possibility where you live. Kim

The most common "eater" of rose leaves in California is the Bristly Rose Slug, the larvae of the Rose Sawfly. The sawfly is a pudgy little wasp. It lays its eggs on the UNDERSIDES of the leaves and the caterpillars feed on the UNDERSIDES of the leaves. The rose slug is tiny, no more than 1/4-inch long and very slender, and it's the exact same pale green as the undersides of the leaves. Talk about hard to see and find! It's the critter that "skelotinizes" rose leaves. It's pretty easy to get rid of, actually. Almost any good spray will do the job: insecticidal soap, Neem, pyrethrum. The trick is to spray thoroughly UNDER the leaves. Not stand back and spray all over. You have to get UNDER the leaves. By the way, a commonly suggested spray for rose sawfly is BT. It doesn't work. It doesn't work because it's meant for the caterpillars of moths and butterflies. The rose slug is the larvae of a wasp. And I'm not sure of any beneficial insect that preys upon it. As for your rose buds, Applenut has a good idea. Go outside late at night with a flashlight. The critter most likely is an earwig, sowbug or pillbug. It also might be a slug or snail. Joe

In the spring the female leaf cutter bee makes blankets for her young by cutting out semi circles in the rose leaves and wrapping them around them. Every semi circle she bits off is identical. These bees don't stay too long and it doesn't damage the rose plant.

It is not bad for the plant at all. Foliage of any naturally occurring species gets munched all the time by various insects with few, if any, ill effects. It is more a cosmetic or aesthetic issue than anything to be concerned about. I have a high tolerance for leaf disfigurement on most plants as the cure is typically worse than the problem, as most insecticides - and certainly Sevin - will kill off the natural predators and other beneficial as well. I prefer to let nature take its course :-))