PARENT SESSION
Poster Session #62: Parasite-Host Interactions.
Thursday, August 8. Presentation from 8:00 AM to 9:30 AM. Exhibit Hall B & C, TCC
155
Large potential host ranges of Drosophila-parasitic nematodes.
Perlman, Steve*,1, Jaenike, John2, 1 University of Arizona, Tucson, AZ2 University of Rochester, Rochester, NY
ABSTRACT- While there is much data on the actual host ranges of parasites in nature, very little is known about their potential host ranges, in particular the contribution of host phylogeny to the ability of a parasite to colonize a new host species. We assessed the ability of five different species of allantonematid nematode parasites to infect and develop in 24 taxonomically diverse species of mushroom-feeding Drosophila flies. The experimental infections showed that the potential host ranges of the nematodes are much larger than actual ranges, even for parasites with only one known host species in nature. Novel hosts that are distantly related from the native host are much less likely to be infected, but among more closely related hosts, there is much variation in susceptibility. Thus, there is a noticeable, but noisy, phylogenetic signal to the potential host range of a parasite. Potential host ranges were found to differ greatly between the related parasite species. All nematode species that successfully infected novel hosts produced infective juveniles in these hosts. Most novel infections did not result in significant reductions in the fecundity of female hosts. The large potential host ranges of these parasites, in combination with the high potential for host colonization due to shared mushroom breeding sites, explain the widespread host switching observed in comparisons of nematode and Drosophila phylogenies.
KEY WORDS: parasitism, coevolution