Tragardh, I. 1939 . Sveriges skogsinsekter. [Insects of the Swedish Forest.]. Hugogebersforlag Stockholm, Sweden 416 pp.
Notes: Scale species mentioned include Chionaspis salicis, Physokermes piceae, Gossyparia spuria and Cryptococcus fagi.
Tragardh, I. 1939 . Sveriges skogsinsekter. [Insects of the Swedish Forest.]. Hugogebersforlag Stockholm, Sweden 416 pp.
Notes: Scale species mentioned include Chionaspis salicis, Physokermes piceae, Gossyparia spuria and Cryptococcus fagi.