Five deciduous Rhododendron species (R. albamense Rehder, R. austrinum (Small) Rehder, R. calendulaceum (Michaux) Torrey, R. canescens (Michaux) sweet, and R. prunifolium (Small) Millais) were tested for resistance to oviposition by the azalea lace bug (ALB), Stephanitis pyrioides (Scott). Control plants were R. mucronatum ‘Delaware Valley White’ (DVW), a susceptible evergreen variety. Rhododendron canescens and R. prunifolium were the least suitable for adult survival and the most resistant to oviposition in no-choice tests repeated six times during a two year study. All deciduous species were significantly less preferred than DVW early in the season corresponding with activity of first generation ALB adults. In late season assays corresponding to activity of second and third generation ALB adults, only R. canescens was consistently less preferred than DVW.
The research reported here was supported, in part, by a grant from the Horticultural Research Institute, Inc., 1250 I Street, NW, Suite 50, Washington, DC 20005. The authors gratefully acknowledge the cooperation of Callaway Gardens personnel for making the facilities and gardens available for research purposes. Appreciation is extended to Leon W. Hepner, Professor Emeritus, for identification of leafhopper specimens and Russell F. Mizell, III, University of Florida, for comments on the manuscript.
2Assistant Professor and Research Technician, respectively.