A heteroecious parasite is one that requires at least two hosts. The primary host is the host in which the parasite spends its adult life; the other is the secondary host. Both the primary host and an unrelated alternate host are required for the parasite to complete its life cycle. This can be contrasted with an autoecious parasite which can complete its life cycle on a single host species. Many rust fungi have heteroecious life cycles:[1]

In parasitology, heteroxeny, or heteroxenous development, is a synonymous term that characterizes a parasite whose development involves several hosts.[2]

Fungal examplesEdit


The phenomenon of heteroecy was first discovered by A.S. Ørsted in 1863.[3]


  1. ^ Schumann, G. & D'Arcy, C. (2010). Essential plant pathology. APS Press
  2. ^ Odening, Klaus (1976-01-20). "Conception and terminology of hosts in parasitology". In Dawes, Ben (ed.). Advances in Parasitology. 14. Academic Press. pp. 24–25. ISBN 978-0-08-058060-9.
  3. ^ Ørsted, A.S. (1863) Om Sygdomme hos Planterne, som foraarsages af Snyltesvampe, navnlig om Rust og Brand og om Midlerne til deres Forebyggelse. Kjøbenhavn