infestation

from WordNet (r) 3.0 (2006)

infestation
    n 1: the state of being invaded or overrun by parasites
    2: a swarm of insects that attack plants; "a plague of
       grasshoppers" [syn: {infestation}, {plague}]

from The Collaborative International Dictionary of English v.0.48

Infestation \In`fes*ta"tion\, n. [L. infestatio: cf. F.
   infestation.]
   The act of infesting or state of being infested; molestation;
   vexation; annoyance. --Bacon.
   [1913 Webster]

         Free from the infestation of enemies.    --Donne.
   [1913 Webster]