Abstract: To study whether Ophraella communa has host specialization on Ambrosia artemisiifolia and Xanthium sibiricum, a dual-choice trial was conducted to study the host selection of the O. communa originated from A. artemisiifolia (ragweed cohort) and X. sibiricum (cocklebur cohort), with the leaf consumption of the two cohorts on five relative plants X. sibiricum, A. trifida, Helianthus annuus, H. tuberosus, and A. artemisiifolia measured. The ragweed cohort O.communa showed a significant preference for A. artemisiifoliaover X. sibiricum, while the cocklebur cohort O. communa showed a significant preference to X.sibiricum over A. artemisiifolia, as manifested by the relative over-preferences. The leaf consumption by the two cohorts differed significantly on sunflower, but had no significant differences on the other test plants. Ragweed cohort showed a significant preference to A. artemisiifolia over the other test plants, with a consumption of leaf discs by 51.27 mm² in 24 hours, but showed less difference in the preference to other test plants, with the consumption of leaf discs by <40 mm². The leaf discs consumption of A. artemisiifolia by cocklebur cohort was 52.24 mm², not different from the consumption of sunflower and A. trifida but greater than that of X. sibiricum and H. tuberosus, and no significant difference between the latter two plants. It was suggested that X. sibiricum could be a suboptimal host plant as an alternative to optimal A. artemisiifolia for the leaf beetle O. communa.

Key words: Changbai Mountain, Ecotone between forest and marsh, Regional climate change, Succession