ABSTRACT
There is a paucity of information relative to the molecular biology of protozoa successfully used for the control of harmful organisms. Many articles have been published pertaining to those organisms that can be considered for biological control. In our laboratory we first became aware of this control mechanism when Nosema strigeoidea was used as a hyperparasite to control the eye fluke, Diplostomum spathaceum. 1 , 2 The molecular mechanism for this response was not investigated, but it was noted that the microsporidan was very effective against the cercariae of D. spathaceum. One concern we had was whether or not the microsporidan was host specific. If utilized in aquatic habitats would it infect other organisms including humans?
