Persistence of mermithidae (Nematoda) infections in black fly (Diptera: Simuliidae) populations.

Data on the persistence of mermithid infections in black fly populations over several years indicate mermithid infection rates are relatively stable over several years in a stream. These data were from specific sites in a variety of streams all having the same simuliid fauna present each season. This suggests that the suitability of the stream bed for the free living phase is very important in regulating mermithid populations.