Source : Webster's Revised Unabridged Dictionary (1913)

Heteroecious \Het`er*[oe]"cious\, a. [Hetero- + Gr. ? house.]
   (Bot.)
   Passing through the different stages in its life history on
   an alternation of hosts, as the common wheat-rust fungus
   ({Puccinia graminis}), and certain other parasitic fungi; --
   contrasted with {aut[oe]cious}. -- {Het`er*[oe]"cism}, n.

Source : WordNet®

heteroecious
     adj : of parasites; passing through different stages of the life
           cycle on different host species; "heteroecious fungi";
           "heteroecious insects" [ant: {autoecious}]