Goldenrod Gall Fly

Duck to avoid parasites

cwilcox | March 8, 2010

During the summer, strange formations can be found on some species of Goldenrod. The stems become enlarged and form a hardened golf-ball like object called a gall. Cut into this weird sphere and you'll quickly find what causes the plant to create such a strange object: the larvae of the Goldenrod Gall Fly. The Goldenrod Gall Fly (Eurosta solidaginis) is a parasite which uses the Goldenrod for protection and nutrition for a whole year while it grows and pupates. When it does, it can seriously damage the Goldenrod, even prevent the plant from flowering and producing seeds. This is a serious…