[4][5][6] The galls of its all-female parthenogenic generation are pink and covered in hairs that are white, red, or brown.

[7] The body of a gall can end with an extended neck when they are of considerable size.

In the spring, the bisexual generation of males and females induces much smaller galls with shorter hairs.

[8][2] The female that correlates with the sexual generation is typically black, and it is usually darker than the male counterparts with the exception of the antennae, while the female unisexual generation has a reddish tone.

[2] There have been signs of generational changes in the F. crystallinum due to the galls depicting developed holes.