Second intermediate host-specificity of Haematoloechus complexus and Haematoloechus medioplexus (Digenea: Haematoloechidae)

Second intermediate host-specificity was examined for 2 species of the frog lung fluke genus Haematoloechus. Nine species of freshwater arthropods were exposed to cercariae of H. complexus and H. medioplexus. Metacercariae of H. complexus developed in all anthropod species used. Metacercariae of H. medioplexus developed only in anisopteran odonate naiads. This difference in host utilization may have epizootiological implications. The potential de- velopment of H. complexus in a greater number of arthropods than H. medioplexus may increase the chances of ingestion of H. complexus by an anuran host. The range of arthropods parasitized by H. complexus indicates that host-specificity of the metacercarial stage of this fluke is not restricted by the phylogeny of aquatic arthropods.