Susceptibility of Three Rose Genotypes to Japanese Beetle (Coleoptera: Scarabaeidae) Adult Feeding    (View PDF)

Paul Thomas Tiddens and Raymond A. Cloyd

Abstract: Japanese beetle (Popillia japonica) adults are a major insect pest of cultivated roses, causing extensive feeding damage to both foliage and flowers. Insecticides are primarily used to minimize adult injury to roses; however, insecticides may be harmful to natural enemies and their use may be restricted, particularly in public gardens. An alternative management strategy is the use of rose genotypes that express some level of herbivore tolerance. However, there is little information on rose genotypes that are tolerant or less susceptible to adult Japanese beetle leaf feeding. This study evaluated the susceptibility of three new rose genotypes introduced into the Crasberg Rose Garden at the Chicago Botanic Garden, Glencoe, Illinois, U.S. The genotypes were Rosa ‘Radrazz’ Knock Out™, Rosa ‘Crimson Bouquet,’ and Rosa ‘Love and Peace.’ Two laboratory experiments, a no-choice and multiple-choice leaf-feeding assay, were conducted in 2002 and 2003 to assess susceptibility of the new rose and two established genotypes to Japanese beetle adult feeding. Although there were significant statistical differences between the rose genotypes, in almost all cases the mean percentage damage rating exceeded 50%. Mean percentage damage ratings for the 2002 and 2003 no-choice experiments ranged from 15% to 78% and 60% to 75%, respectively. Mean percentage damage ratings for the 2002 and 2003 multiple-choice experiments ranged from 34% to 58% and 47% to 53%, respectively. These results indicate that all the rose genotypes tested are susceptible to Japanese beetle adult feeding and may not be appropriate selections for use in areas with established Japanese beetle populations.

Keywords: Host plant resistance; integrated pest management; Japanese beetle; plant health; Popillia japonica; Rosa spp

https://doi.org/10.48044/jauf.2006.014