RANGE EXPANSION OF GREEN TREEFROGS (HYLA CINEREA) IN SOUTHERN ILLINOIS: NO EVIDENCE OF PARASITE RELEASE.

For several decades, green treefrogs (Hyla cinerea) have been undergoing rapid range expansion northward and eastward in Illinois, Indiana, and Kentucky. While range expansion of green treefrogs in these states may be linked to climate change, a recent study suggested this expansion could be facilitated by parasites, given that expanded range populations of green treefrogs from Kentucky and Indiana exhibited significant decreases in helminth species diversity compared to those examined from historical locations of Kentucky. Because rapid range expansion may lead to hosts escaping their parasites (= parasite release), a reprieve from parasitic infection could allocate additional resources to growth and reproduction and thus facilitate the expansion.

HELMINTH DIVERSITY OF GREEN TREEFROGS (HYLA CINEREA) IN THEIR EXPANDED GEOGRAPHICAL RANGE.

There has been a growing interest in characterizing the parasite faunas of species populations as they expand their geographical ranges as a result of climate change. Expanded-range populations often exhibit lower parasite diversity than historical-range populations, and reduced parasitism may, in part, be attributable to expanded-range populations escaping their native range parasites. The present study compares the helminth faunas of green treefrogs (Hyla cinerea) from 4 historical and 4 expanded-range populations to determine whether these latter populations have undergone parasite escape.

Host Diversity Affects Parasite Diversity: A Case Study Involving Unionicola spp. Inhabiting Freshwater Mussels.

Water mites of the genus Unionicola are common parasites of freshwater mussels, living on the gills or mantle of their hosts and using these tissues as sites of oviposition. Although surveys of this mite fauna among North American unionid mussels indicate that these mites represent highly diverse assemblages, we know very little regarding the determinants of Unionicola species diversity among their molluscan hosts. The present study addresses the relationship between host diversity and mite diversity for Unionicola assemblages associated with unionid mussels of North America.

A Comparison of Helminth Faunas of Cope's Gray ( Hyla chrysoscelis ) and Green ( Hyla cinerea ) Treefrogs in Areas of Recent Niche Overlap.

This study compares the helminth faunas between Cope's gray treefrogs ( Hyla chrysoscelis ) and green treefrogs ( Hyla cinerea ), in areas where they have recently overlapped due to range expansion by H. cinerea , to determine whether or not 2 species of frogs with a high degree of similarity in many of their life history traits also exhibit similarities in the composition of their helminth assemblages. Results of this study did not find significant differences in helminth species diversity when sympatric and allopatric populations of the same species of frog were compared.

Patterns of species richness among assemblages of Unionicola spp. (Acari: Unionicolidae) inhabiting freshwater mussels (Bivalvia: Unionoida) of North America.

Water mites of Unionicola species are common symbionts of freshwater mussels, living on the gills or mantle and foot of their hosts and using these tissues as sites of oviposition. Although surveys of the mite fauna among North American mussels suggest that these mites represent highly diverse assemblages, there are currently no quantitative data characterizing Unionicola species diversity among their molluscan hosts. The present study addresses patterns of species richness of Unionicola assemblages from freshwater mussels, including the relationship between richness and host specificity among these mites.

Mitochondrial genome sequence of Unionicola parkeri (Acari: Trombidiformes: Unionicolidae): molecular synapomorphies between closely-related Unionicola gill mites.

The mitochondrial genome of Unionicola parkeri is a 14,734 bp circular DNA molecule. The sequence and annotation revealed a unique gene order, related to but distinct from the gene order in the closely related species U. foili.

Mitochondrial genome sequence of Unionicola foili (Acari: Unionicolidae): a unique gene order with implications for phylogenetic inference.

The mitochondrial genome of Unionicola foili is circular, 14,738 bp in length, and contains several notable features. The sequence and annotation revealed a unique gene order, continuing a pattern of highly rearranged mitochondrial genomes in the Trombidiformes. U.

Host specificity among Unionicola spp. (Acari: Unionicolidae) parasitizing freshwater mussels.

Water mites of Unionicola spp. are common parasites of freshwater mussels as adults, living on the gills, or mantle and foot of their hosts and using these tissues as sites of oviposition. The present study addresses specialization among North American Unionicola mussel-mites using 2 measures of host specificity: (1) the number of host species used by a species of mite; and (2) a measure that considers the taxonomic distinctness of the hosts utilized by mites, weighted for their prevalence in the different hosts.

Random amplified polymorphic DNA analysis of kinship within host-associated populations of the symbiotic water mite Unionicola foili (Acari: Unionicolidae).

Kinship relations within populations of unionicolid water mites are not well known, owing to their complex life cycles and the fact that interactions between active and resting stages for some species are transitory. A number of species of unionicolid water mites are, however, obligate symbionts of freshwater mussels and spend most of their life cycle in association with these hosts. Among these species of mites, parents and offspring are more likely to co-occur and thus provide opportunities to address questions related to the structure of the mating system.

Host sex preferences and transmission success by the water mite Unionicola foili (Acari: Unionicolidae) parasitic on the midge Chironomus tentans (Diptera: Chironomidae).

This study examined whether ecoparasitic larval Unionicola foili exhibited a sex bias when infecting laboratory populations of the host insect Chironomus tentans and whether an association with male or female midges increased the likelihood of larval mites returning to the aquatic habitat. When laboratory populations of C. tentans were exposed to larval U.