I lost a pretty good Double Delight to them or something similar--defoliated the plant to the point where it couldn't recover.

That is a bummer, thanks for letting me know. Guess I won't be leaving them.

Something always comes to eat them. Get them every year. Some times i hunt for them and squish. If you gently tap the rose big ones will fall to the ground. The little guys are attached by a web like and will hang in the air. If you just knock them off without squishing they will crawl back up.

I usually fold the rose leaf over the sawfly and squish it between the leaves.

In my garden it seems to depend on the weather. If June is cooler/wetter than average, the sawflies stick around to raise multiple families and the roses will be defoliated. If June is hot and dry, the sawflies disappear after the first batch and the roses recover just fine. I have more sawflies than usual this year, so I've been hunting and squishing them. The catbirds are helping me out also.

Thanks everyone. I appreciate all the insight. Will try a mixture of everyone's suggestions and hopefully they'll bugger off once it heats up.

Predators such as wasps always control them in my garden. But if you are seeing heavy loss of foliage, say 1/3 or more, you can spray with a soap solution, getting full coverage of the undersides of leaves on the plants that are affected.

I've been experimenting with planting French Marigolds around our roses. Last year was my first year of experimenting and things went very well so this year I have planted Marigolds again to see what happens...

Previous years I used Safer Insecticide Soap and Spinosad with success... I recommend spraying the underside of leaves but also the top side of leaves and canes... And I recommend spot testing the bush before applying to entire bush...

I have noticed, and it may be a coincidence, that my roses planted next to my allium seem less affected. I'm planning on adding more allium this fall around the rest of my roses and hopefully that will help.

The adult sawflies prefer to lay eggs on certain varieties, for example some glossy-leaved roses of wichurana heritage. So you have to consider those preferences when you look for repellent effects. Some roses will not be affected regardless of companions, and others will be.

I got a ton of them on a few roses for some reason, and that does keep up from year to year once it starts, in my experience here. But it used to be in better balance without me having to do much. I don't regret not freaking out over them before. Even now I just watch out for how many there are. A few don't bother me (unless they are on a tiny rose). The roses who get way too many can be taken care of when/if that happens, imho :)

I did some reading and found out they fall to the ground to pupate and then the new sawfly lays eggs for another batch.

I finally found my answer. I noticed that all my newly planted roses have sawfly. I first noticed the sandy coloured spotted leaves. I just snipped them off and hope it helps. I am beginning to regret buying all my roses from the same nurseries. It seems the new ones are getting sawfly and rrd.