Leaf consumption capacity and damage projection of Octodonta nipae (Coleoptera: Chrysomelidae) on three palm species.
The nipa palm hispid, Octodonta nipae (Maulik) (Coleoptera: Chrysomelidae), is considered to be the most important invasive pest of palms in southern China. To evaluate the differences in the damage potential of O. nipae on three different host palms, the daily feeding rates of O. nipae were studied based on the age-stage, two-sex life table theory. There were no significant differences in consumption rate during the first to third instar among palm species. However, O. nipae consumed a greater area on Chinese windmill palm Trachycarpus fortunei (Hooker) H. Wendland and Canary Island date palm Phoenix canariensis Chabaud leaves than on pygmy date palm Phoenix roebelenii O' Brien leaves. Females consumed more food than males on all three palms tested. The net consumption rates were 11,007.6, 8,998.0, and 5,773.5 square millimeters per individual for O. nipae reared on Chinese windmill palm, Canary Island date palm, and pygmy date palm, respectively. The host palm had a significant effect on consumption by both male and female O. nipae, and the damage potential was higher on Chinese windmill palm and Canary Island date palm. According to the finite consumption rate, O. nipae could cause more severe damage on Chinese windmill palm and Canary Island date palm than on pygmy date palm. These results provide the first assessment of leaf area consumed and the potential damage by O. nipae on three host palms. Population projections based on age-stage, two-sex life tables, and stage-specific consumption rates can reveal the stage structure and damage potential of the pest population. This approach offers a promising tool for quantitative assessment of the feeding capacity of this invasive beetle.