Ratzeburg, J.T.C. 1852 . Die Ichneumonen der Forstinsecten in forslicher und entomologischer Beziehung. Ein Anhang zur Abildung und Beschreibung der Forstinsecten. Nicolaischen Buchhandlung Berlin I-XVIII, 272 pp.

Notes: Title in English: [Ichneumonidae of Forest Insects in Forestry and Entomological Relationships; An Appendix to the Illustration and Description of Forest Insects]. Species mentioned include Chermes piceae, C. strobi, Coccus aceris, C. alni, C. betulae, C. cambii, C. pini, C. pruni, C. quercus and C. racemosus.