While spraying off a large area to prepare for new garden I came across this wild rose with furry balls growing directly from the leaves and stem sides. Attached is photo. I sprayed this area over a year ago with Roundup but didn’t get back till now. The plant may have survived this spraying as I avoided it as soon as I spotted it amongst everything else.What is it? Could it have been the previous Roundup affecting the plant? Thanks Lar Duffy
This is an unusual, though not rare, condition caused by a wasp which lays its eggs in the bud of the rose stem. The eggs produce hormones that cause the formation of a gall on the stem that grows out, inside which the larvae are protected. When full size the larvae emerge, having pupated in early spring. It is known as ‘moss gall’, ‘Robin’s pincushion’ or ‘Bedeguar gall’ and is caused by the wasp Diplolepis rosae.