Wu, S.A. 2000b Descriptions of male and immature stages of Cryptococcus ulmi Tang et Hao (Homoptera: Coccoidea: Eriococcidae) with brief notes on its biology.. Entomotaxonomia 22(4): 251-256.

Notes: The crawler, second instar female and male, prepupa, pupa and adult male of Cryptococcus ulmi are described and illustrated for the first time, the adult female is redescribed, a key to all stages is given, and biological notes are provided.