I am just a novice but I tried insecticidal soap on rose slug last year and it didn't do the trick. I do use insecticidal soap on other things....

But this is a great question, I am interested in the answer.

Hi,
I've had less of a problem since I've been hanging bird feeders. I put out the nyjer(black thistle) seed to attract the small birds like finches and chickadees. It doesn't seem to attract as many nuisance birds like grackles in case you are worried about that. I see the chickadees picking bugs off my large rose shrubs/climbers all the time.
Remy

Praying Mantis eat everything and anything. Here there is a tiny grey bird that comes through in groups and clears them out. I think they are Psaltriparus minimus.

what is the proper climate zone for the praying mantis? They don't seem to grow here by themselves and it must be for a reason.

Wasps devour my rose slugs and I needn't spray anything. Oh, common wrens are amazing little cleanup machines and they have beautiful song, too.

Using natural predators is great, but they won't come to you garden if there's no meat, so you have to permit the sawflies to get a head start. That means a few perforated or skeletonized leaves. Once the good guys arrive, you get a healthy equilibrium.

Avoid spraying insecticides -- this hurts the wasps and other good bugs. And keep cats indoors -- they are a songbird menace.

Thanks, everybody, for the suggestions. We already have plenty of birds hanging around, though, as I feed them all winter and our only cat is too old to bother them. But my feathered friends don't seem to be making a dent. They are probably too busy sitting around waiting for the berries and cherries to ripen. (Sigh.)

I see that I shall have to encourage the population of wasps. Will any wasps work, or do they have to be a particular type? Also, do praying mantises actually eat everything or just the bad guys? I probably shouldn't get them if they are going to be gobbling up the good bugs too!

A Praying Mantis is unlikely to eat a rose slug. The slugs are pretty small and move slowly. The PM usually sets up an ambush and hooks anything that comes by. Including bees and hummingbirds. If you look closely at the pic below, you will notice the bee that came to dinner.

{{gwi:228436}}

I read on the Australian gardening forum that a tea made from espresso coffee kills slugs. (They ingest the caffeine and it zaps them.) I haven't yet tried it but I'll let you know how it works.

@anita22 I set up two bird feeders, one with black oil sunflower seeds and the other with nyjer and sure as shooting I've had several birds that perch on my rose buds, eating the rose slugs right off. Thanks for the advice! I'll have to do the corn trick to get grackles once japanese beetles start showing up here