The goldenrod galls turn from green, to this pretty autumnal red, to a burnished bronze colour, reflecting of course, the colour transformations of the plant stems as they age over the fall and winter and eventually die back by late spring when the new goldenrod gall fly emerges. In the meantime, many of these galls are opened by squirrels and birds seeking the fat little grubs (goldenrod fall fly larvae) inside, one larva per gall.