I went out yesterday and ruthlessly pruned out all canes that had the tell-tale swellings of rose stem girdler, trying desperately to reduce their number for next year. I will have a bonfire today to deal with all the prunings and feel satisfaction imagining the pests burning up in the fire! Roses hardest hit:
I have over 80 roses in this garden, large and small, antique and modern and most are rarely infested with rose stem girdler, but the roses I listed above are always hit here, year after year, and so can't attain their potential. I'm wondering what it is about these in particular that are so attractive to this pest. And how far will these small flat-headed, metallic beetles (Coleoptera) travel for their choice of egg laying ground? There are no stands of raspberry or blackberry canes in this neighborhood that I have ever seen to harbor the pests - nor does anyone else in my area grow anything more than the occasional hybrid tea rose and yet judging by the number of infested canes in my yard (and many of those canes with 3, 4, 5 or more separate swollen girdling sites) there was a lot of insect activity this year, more than usual I'd say. I wasn't able to keep on top of watching for this pest and keeping it pruned out the last two years due to health issues and I'm hoping that now that I am much more physically able I will be able to reduce the numbers simply by being more diligent. If not, these particular roses will have to go. We'll see what happens next year after I've cleaned the garden out this fall. Just hoping my bi-focals and I haven't missed too many and I will have to go over everything again when the leaves are gone, or in very early spring when the snow melts to catch any more swollen canes and remove them. Doesn't seem there is much else I can do, is there?