Heteroecious
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 are prime examples of a heteroecious life cycle. Parasitic heteroecious fungi include ▪
Gymnosporangium; the juniper is the primary host and the apple, pear or hawthorn is the secondary host ▪
Cronartium ribicola; the primary host are white pines, and currants the secondary. ▪
Hemileia vastatrix; Primary host is coffee plant; Unknown alternate host ▪
Puccinia graminis; Primary hosts include: Kentucky bluegrass, barley, and wheat; Common barberry is the alternate host. ▪
Puccinia coronata; Oats are the primary host;
Rhamnus spp. is alternate host. ▪
Phakopsora meibomiae and
P. pachyrhizi; Primary host is soybean and various legumes. Unknown alternate host.