Carpenter, Geo. H. The Life-Story of Insects. Cambridge University Press 1913. Archived from the original on 2015-03-30. Retrieved 2015-03-29. https://www.gutenberg.org/ebooks/16410
Richards, O. W.; Davies, R. G. (1977). Imms' General Textbook of Entomology: Volume 1: Structure, Physiology and Development; Volume 2: Classification and Biology. Berlin: Springer. ISBN 0-412-61390-5. 0-412-61390-5
Carpenter, Geo. H. The Life-Story of Insects. Cambridge University Press 1913. Archived from the original on 2015-03-30. Retrieved 2015-03-29. https://www.gutenberg.org/ebooks/16410
Carpenter, Geo. H. The Life-Story of Insects. Cambridge University Press 1913. Archived from the original on 2015-03-30. Retrieved 2015-03-29. https://www.gutenberg.org/ebooks/16410
Gordh, Gordon; Headrick, David H. (2010). "Imago". A Dictionary of Entomology, 2nd ed. Wallingford, Oxfordshire, UK: CABI. p. 725. ISBN 978-1845935429. OCLC 441191893. https://archive.org/details/dictionaryofento0000gord/page/724/mode/2up