Preference of temperate Chinese elms (Ulmus spp.) for the adult Japanese beetle (Coleoptera : Scarabaeidae)

Trees of newly acquired Ulmus species originating from the temperate region s of China and growing at The Morton Arboretum, Lisle, IL, were evaluated i n no-choice and multiple-choice laboratory bioassays and cage-studies for f eeding preference for adults of the Japanese beetle, Popillia japonica Newm an. Ulmus lanceaefolia, U. prunifolia, U. pseudopropinqua, and U taihangsha nensis were less preferred for feeding by adult Japanese beetles. No-choice , multiple-choice, and cage feeding studies revealed that Ulmus wallichiana was moderately preferred, and I! procera and U. americana were highly pref erred for feeding. Dry fecal pellet weights were strongly correlated with t he percent of leaf tissue removed. Feeding preference in the multiple-choic e study was strongly correlated with feeding preference in the cage study a nd in the no-choice study. Likewise, adult feeding preference in the cage s tudy was strongly correlated with preference in the multiple-choice and no- choice studies. The less preferred species of lanceafolia, U. prunifolia, U . pseudopropinqua, and U taihangshanesis show promise for future elm breedi ng programs.