It is not rose slugs, which make holes in mature leaves.

Midge may or may not be a factor. Please say approximately where you live (and add that to your header).

If you found a worm inside the stem, it is a stem borer. I have the Rose Stem Sawfly, but its larva is white with a black head. Stem borers can cause singed growth tips by interrupting the water supply. There may be borers further down the stems; investigate by squeezing for hollowness or maybe snipping. These pests originate with eggs laid near the growth tips. They eat their way downward as they grow. You may see a dark spot in the cross-section of pith-- this is the worm's track. I get adequate control by just finding and killing a few worms per year.

However, I don't think these don't eat off growth tips. The feces indicate some good-sized worm or beetle. Or are they extruded from the worm tunnels? Midge wouldn't leave noticeable feces-- the larvae are around 1/16" to 1/10".

I live in the mountains of Lake Tahoe in Nevada. High elevation and dry. We have had two weeks of rainy cold weather so perhaps that has something to do with the damage, but it is odd that the tips are hollow. Only goes down about 3/8" of an inch. Rest of the cane is fine.

I've not seen any report of rose midge in Nevada. You can probably rule that out.

I guess I'm not clear on your symptoms. How can the growth tips be burnt and also chewed off and hollowed out? If you could get a sharp picture, maybe someone could ID.

I can't make an identification based upon the picture you've offered. If you can get much closer I might be able to make at least an insect order identification.

Based upon that image alone I can say you've probably found a rose slug of some sort (if I recall correctly, there is more than one species of sawfly that are collectively known as rose slugs). However, that image is not distinct enough for me to be certain it's a rose slug and not the caterpillar of some moth or other. I do feel pretty sure that the insect is the larva of either a sawfly (most likely), or a moth (less likely), or a beetle (much less likely), or a fly (even more less likely).

(Oh yeah, in case you've never heard of sawflies? They are very distant "relatives" of ants, bees, and wasps, except they pretty much all eat plants of one kind or another. Many of them are pests of trees. They don't sting (no stinger), and the adults aren't the sorts of flashy insects one is likely to notice. Thus most people have never heard of them.)

Unfortunately, I can't get a picture of it because I have since cut them all out. One theory I have now is that the cold snap may have done the majority of this damage. Doesn't explain the hollow part or the dirt stuff left behind but the problem has not reoccurred in the last few days.