I've noticed that a lot of the wild roses in the 'new' wood (the Histon WI wood) have Robin's Pincushion galls on them. I've known for as long as I can remember that these are caused by a gall wasp (Diplolepis rosae), but what I didn't know is that apparently they are most common on plants that are under stress (such as from drought, waterlogging, or hedge-cutting). I wonder what particular stresses these plants are under? They appear to me to be growing vigorously and look very healthy. Anyway, whatever the reason for their relative abundance, the galls are wonderful structures to look at.
I knew about the amazing gall wasp construction Penny, but not about the stress, that is interesting. Perhaps waterlogging if they are looking OK.?
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