Try a horticultural oil spray first, as the neem will also wipe out predators. If the oil spray doesn't work, then go for a heavier weapon.

Will try it. Thanks, Hoovb. Meanwhile I spent an hour squishing yesterday. Hope it helps!

I had a lot of rose slugs earlier this year and picked them off. Anything you spray to kill them will wipe out everything else as well so don't do it. I would spray with water as you would for aphids but not too hard and hopefully it will knock them off.

Spinosad works on the kind I have (the kind that curl up like a snake) and leaves the beneficials that don't eat the leaves, unless you kill them on contact with it perhaps. Just make sure not to spray when bees are out, and you might cut off any open blooms to be sure. It's toxic to bees until it's dried completely. If the leaf-cutter bees are active, I'd not spray it because I'm afraid it would hurt them even when dry (?).

Squishing is best, but I had so many last year that they ate ALL of the foliage eventually on certain roses, even with my daily squishing. That's just too many!

I am also having trouble with bugs on my two knockout roses. I will try to find some neem oil at walmart to see if I can control them. how often do you need to spray neem oil on roses to kill the slugs.