It took me a while to ID this critter, as there is so much misinformation out there.
But the evidence of what I am dealing with, is in the classification of the insect's shape, form and colouration.
It looks as though we have a Cnaemidophorus rhododactyla larvae (Rose Plume Moth) feeding on these Rosa glauca flower buds.
I've seen posts naming this same larvae as Rose Budworm, Leaf-roller, Sawfly and Rose Chaffer larvae.
Something was amiss. The shape and colouration of the larvae didn't match the information I looked through. Thankfully, the tapered - semi dotted red stripe behind the head was a true help in trying to ID it.
It's a alien Moth, originating from Europe. This saddens me, as I hate to see non-native insects devouring my plants. For now, the control I am using is hand removal. I collected about 7 off this rose bush alone. They fed on nearly 20 blooms already, starting from the base of the bush. They make huge puncture holes in the rose buds and eat the entire contents, leaving only the sepal leaves (rose bud outer casing leaves).
One positive outcome: I tossed the larvae on the patio near by and a lovely Robin came and had an easy meal. Yum!
I love Rosa glauca for it's simple, open faced flowers that pollinators adore. I am really vigilant in trying to remove the larvae as much as possible. We had such a prolonged cold spring, and now to see potential blooms withering from damage, is rather disheartening.
Just note: It is important to get specific info in dealing with larvae, especially if you want use biological controls like BTK sprays.
Use this great site to help you pin-point and ID what you are dealing with before you choose a spray control or removal. ----> Bug Guide Website Don't forget, there are many beneficial insects that are a gardener's best friend.
Click on this link for more info and photos of the Cnaemidphorus rhododactyla larvae and moth.