INFLUENCE OF ODONATE INTERMEDIATE HOST ECOLOGY ON THE INFECTION DYNAMICS OF HALIPEGUS SPP, HEMATOLECHUS-LONGIPLEXUS, AND HEMATOLECHUS-COMPLEXUS (TREMATODA, DIGENEA)

The prevalences and relative densities of Halipegus spp., Haematoloech us longiplexus, and Haematoloechus complexus metacercarial infections in anisopteran (dragonfly) and zygopteran (damselfly) odonate intermed iate hosts were examined. These measures of infection were compared in relation to the ecological habits of the host species. Also, the exte nt of second intermediate host specificity was compared between the 2 species of Haematoloechus. Eighteen species (N = 934) of odonates were dissected and examined for metacercariae. Halipegus spp. generally ha d the highest prevalences and relative densities of infection when com pared with Haematoloechus spp. in this system. Except for 1 host speci es, no significant differences in levels of infection were found betwe en the 2 species of Haematoloechus in anisopterans. Haematoloechus lon giplexus was a second intermediate host specialist, being found in ani sopteran odonates only. In contrast, Haematoloechus complexus was a ge neralist and was found in both anisopteran and zygopteran hosts. Diffe rences in infections among host species suggest that variations in odo nate ecology are sufficient to influence the suitability of larval odo nates to serve as intermediate hosts for these frog trematodes.