Chris Wilson, interim chair of the UF/IFAS Soil, Water, and Ecosystem Sciences Department, became interested in pesticide impacts on pollinators after observing a product label indicating insecticide treatment on a bag of pansies. This led to a research project focused on understanding how pesticide use in ornamental plant production affects pollinators such as bees, butterflies, and hummingbirds.

Wilson, in collaboration with his wife, Sandra Wilson, a professor in UF/IFAS Environmental Horticulture, received a $750,000 grant from the USDA National Institute of Food and Agriculture to investigate methods for minimizing pollinator exposure to insecticides. Their goal is to develop guidelines for industry practices that protect pollinators while maintaining pest control in the sector, which is valued at over $21 billion annually.

“Pollinators, which we are trying to support by planting flowering ornamentals, may be unintentionally harmed by our efforts to help them,” said Sandra Wilson.

The research focuses on how different pesticide application methods influence pesticide levels in nectar and pollen. Early experiments examined thiamethoxam, a systemic insecticide, applied to plants like Indigo Spires salvia. 

Results showed that soil drenching with the pesticide led to significantly higher concentrations in nectar (up to 117 times higher in some cases) compared to spraying. Interestingly, drenching also resulted in higher pesticide levels than spraying, contrary to initial expectations.

In a related study on lantana, the researchers found that spraying thiamethoxam on the plants generally did not result in detectable pesticide levels in nectar, possibly due to the plant’s tissue characteristics. However, soil drench applications increased pesticide concentrations as application rates and flower development advanced.

Future efforts include further research on pesticide effects and the dissemination of findings through workshops and educational materials. The goal is to collaborate with the ornamental industry to establish best practices that balance pest management with pollinator conservation.

*Featured photo courtesy of UF/IFAS.

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