Population dynamics and ecological drivers of the naturalized weevil Ochyromera ligustri: A potential biological control agent of invasive Ligustrum sinense

Ochyromera ligustri, commonly known as the ligustrum weevil, is a non-native insect that has become naturalized in the southeastern United States. It is a natural enemy of Ligustrum sinense (Chinese privet), a widespread invasive plant in this region, and may have potential as a fortuitous biological control agent against Chinese privet. Despite the ligustrum weevil’s presence in the U.S. since the 1950s, little is known about its ecology, dynamics, or potential impact; either beneficial or harmful. To better understand the ligustrum weevil’s role in the United States, a foundational knowledge of the ecological drivers and population dynamics of the ligustrum weevil is necessary. This study investigates the population dynamics of the ligustrum weevil across five Chinese privet-infested sites with five survey plants each in southern Louisiana over the course of one year by assessing how weevil abundance changes with different biotic and abiotic factors, including host plant phenology, temperature, and seasonality. Additionally, I analyzed iNaturalist observations to explore the broader patterns in ligustrum weevil numbers across its United States distribution. Overall, through both nation-wide iNaturalist and southern Louisiana field surveys, this study investigates the ligustrum weevil’s population dynamics and drivers to inform future studies and management decisions.