Question

Rose Pest   QUESTION: My roses have been attacked by something. There are webs, typically in the crowns of branches from the main canes. Around and within the webbing, the leaves and small stems have died and appear black and are bundled almost as if there is a nest. (It is not spider mite.) Even the large canes of the plants are dying. Upon closer examination, the canes look as if the insides of them have been "bored" out.  Even closer examination showed that the webs and canes were dead to the base of the plants.

I took a local sample to the experts at the Santa Fe Green House and they could not identify the pest (no live insects to be found) beyond saying it was not spider mites.

Any clues? Is this a cane borer of some sort?

I live in Los Alamos, NM and did not even notice these webs until I went to cut off old buds. From far away, the plants looked perfectly healthy.

I'll attach a photo, but I  do have more photos if you would like them.

ANSWER: Yes please another photo would certainly help. There are 5 different kinds of rose borers but I think you have two problems in your rose.

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close up   QUESTION: Okay. Two problems. I've attached a close up of some of the web-like formations. Most of the web formation were larger than pictured here and had leaves pulled up into a big mass of web and black leaves. At the greenhouse we opened up the mass/nest and found nothing inside. Unfortunately, this picture does not capture the size of the webs or the blackness of the nest/mass of leaves inside.

Nor does this picture show the bored out canes.

Answer
Thanks for the photo. I see three problems here. One is that you do have spider mites but to make sure, take a white piece of paper and hold it under some leaves. Hi the leaves and you will be able to see the very tiny spiderlike insects. The other problem with the dead canes is quite normal. When you cut a flower off a rose canes, try an d cut it off at a join. Here is the reason why. The vigor in a rose is all at what is know as the bud eyes. This is where the new canes grow from. The bud eyes on the canes look like the joint lines of your fingers. When you cut back to these eyes the energy is strong enough to seal off the open would of the cut cane. However if you cut too far away from the eye, the cane gets infected and slowly dies back just like your have. Any cut cane will get bacteria in it and that is why it should be sealed by the rose bush to stop if becoming serious. The bigger webs are a spider that likes roses near it's home. I would prune back your roses in all the areas you cut the blooms off. I honestly don't see any evidence of a rose borer. As you know these guys are easy to spot as they are obvious when they make their holes. Hope this helps.