Thank, this is a very smart post.

The term "borer" confuses a lit of people. Holes in cut cane ends signal the relatively benign ones, which are small carpenter bees and certain beneficial pygmy wasps. These are not eating the rose stem; they are just using a small bit of it for a nursery. The SCB, which looks like a large winged black ant, eats only pollen and is a major pollinator. The tiny wasps eat aphids and other small pest insects. I stopped worrying about these 25 years ago. I don't seal cane ends, and I don't prune out the bored cane ends except during spring pruning. Maybe one out of 500 hundred of these goes deep enough to ruin a cane.

On the other hand, the rose stem sawfly larvae will ruin every infested cane unless you catch it early. Look for wilted growth tips on one or a few canes when the rest of the roses look perky. Squeeze canes a foot or two below the wilted tip, checking for hollowness. Look for girdling cuts in the bark near the tip. The villain is a white segmented worm with a black head. It does not enter cut cane ends, but comes from eggs laid near the growth tip. If not discovered and killed, it eats its way down the length of a cane.

I too have the minor holes in the ends of pruned canes; they are rarely bigger than an eighth of an inch in diameter and they don't seem to affect the roses in any negative way. I also don't bother with sealing canes.

Michaelg, thank you for adding to this in such an informative
way!