Response of kudzu ( Pueraria montana var. lobata ) to different types and levels of simulated insect herbivore damage

Simulated herbivory experiments in weed biological control have been used to predict the type and level of damage needed to suppress invasive plant growth and reproduction in the introduced range. Prior to host-specificity testing, this information is used to prioritize potential biological control agents based on their feeding guild and habit. In the current study, two levels of leaf cutting and terminal clipping damage to kudzu, Pueraria montana var. lobata (Fabaceae), were applied to plants over a 2year period near the center (North Carolina) and edge (Delaware) of kudzu’s invasive range. Damage type and levels were selected to imitate feeding by two herbivore guilds found on the plant in its native range. Above- and belowground biomass, total vine length and average internode length were significantly reduced by 75% leaf cutting for plants grown over a single season in Delaware. In North Carolina, several treatments reduced plant biomass, but only 75% leaf cutting was consistent in significantly reducing above- and belowground biomass compared to the control for one- and two-year-old plants. These findings suggest that damage to aboveground plant parts can reduce the ability of newly established plants to produce and store carbohydrates, which can contribute to successful biological control. Therefore, insects in the leaf-feeding guild should be investigated for potential host-specific biological control agents of kudzu in China.