Eriophyid Mite Populations found on Different Rosa Species
Collins, S. B., Q. Cheng, B. England, K. Solo, F. A. Hale, A. S. Windham, D. Byrne, N. Anderson, and M. T. Windham.  2017.  VII International Symposium on Rose Research and Cultivation, Session 7, Poster 9, Angers, France, July 2-7.

Rose Rosette Virus has destroyed thousands of roses in the United States. The virus is vectored by the eriophyid mite, Phyllocoptes fructiphilus. This mite is only found on Rosa species. However, little is known about the host range of eriophyid mites within the genus Rosa. To determine if resistance to eriophyid mites (defined in this study as lack of reproduction on the host), eighteen Rosa species were planted in a completely randomized design at the Plateau Research and Education Center. Eriophyid mite populations were estimated every two weeks from May to September in 2016 by destructive sampling of shoots from which mites were extracted via sieving and then counted using a stereomicroscope. Mite counts were expressed as number of mites per gram of leaf tissue. Due to large variation in data (on a given date, mite counts could range from more than 900 mites/g plant tissue to 30 mites/g plant tissue for R. species where mites could reproduce), the mite counts were converted into a binomial variable where 0 (mite not reproducing on the plant) was less than 20 mites/g plant tissue and 1 (mite reproduction on plant) indicated samples with more than 20 mites/g plant tissue. Low levels of mites were expected on all plants since this study was located in an area with high numbers of roses heavily infested with eriophyid mites which were constantly ballooning onto test plants. Entries of five species (R. arkansana, R. palustris EB, R. clinophylla, R. nitida and R. wichuriana Basye ARE) maintained low mite populations that were not statistically different from zero (p=.05). There were differences in the eriophyid mites’ ability to reproduce on the different accessions of R. wichuriana and R. palustris tested, indicating intraspecific variability in the resistance to mite reproduction. This report uses data from the first year of a multiyear study.