The species (or group of species) that a parasite
infects during its adult stage, when it is capable of reproducing. Many parasites
live in different host
species during different parts of their life cycles. Generally, the parasite
is most harmful to its primary host
. Compare intermediate host
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.