The rose slugs are pupating underground. In spring they will become winged adult sawflies that will lay eggs on rose leaves. Dormant oil will have no effect on them, or likely, much of anything. It may harm beneficial mites. A thorough spray of summer oil might be effective against the little worms; about like using soap, risk of foliar burn.

Thanks Michael. Are the rose slug larvae visible now in the ground...too deep? I'm glad that you answered my question. Less work for me, better for the mites.
So I will go with the summer weight spray (as soon as I see the slugs?) paying particular attention to the day and nighttime temps?
Thanks so much. I hope you are doing well.
Susan

Now I'm reminiscing about Jean and her dawgs and those lovely Victorian homes that she rescued. She did spray lime sulfur in late winter -- I'm thinking it was intended to kill overwintering BS spores and treat scale.

Yes, Jean was here before my time but I know the area where she lived. A wonderful area for a rose garden.
I hope she is still growing roses somewhere!
Susan

Leaves will drop gradually over the winter and spring depending on the severity of cold. It is OK to pick them off if you want to fuss, also OK to leave them on, as I do.

Susan, I doubt you would be able to find the pupae. There probably aren't very many.

Thanks Michael! Subk, I am going to take Michael's advice and do a summerweight spray when I see the slugs. I didn't have any BS issues to speak of last year (I sure hope this year is the same) so I'm not really worried about diseases. I think if I get on top of the slugs I can likely keep them in check with hand picking/oil spraying.
I used the vigorous water spray method last year on the aphids and that worked so well...
Did you have those huge grasshoppers last year? I wonder if they came from mulch or something I brought in...Some of my polyanthas have yet to recover (they were attacked when I was gone for two weeks this summer).
Let me know what you are going to do Subk ad how it works for you.
Susan

Susan I didn't have any grasshoppers, but the rose slugs were again this year pretty devastating for me too. Hand picking is nothing short of a joke. I think I'm going to try spinosad for some control this year as it is the only possible solution I know to try.

For blackspot I WANT to spray sulfur lime/dormant oil simply on the basis that it is what Jean did and she's the only one I've heard of having great success with OGRs here. That's a good enough endorsement for me. I just haven't figured out how to do it.

I am completely confused on how/when to spray LS as well as what is the dormant oil component of it is. I don't understand the dormancy/weather/timing of it and the more searches I do on GW the more confused I get. I keep think there is some illusive hunk of information that I don't have, but I don't know the right questions to ask to find and answer.

If anyone could direct me to a primer on winter spraying that includes how to recognize the ideal timing of it here in my zone as it relates to weather and growth dormancy (and my mostly tea and tea noisette roses) I'd appreciate it!